Scooter - A Miata Journey and ITB Noises
 

Hi all,

This is my first time writing a build thread, but I figured I'll give it a shot and share my journey with my NB Miata. This little car has changed my life and how I see this hobby. The car went from a fun daily driver, to a fun weekend car, to a fun trackcar that goes on the road sometimes.

Let's start with how the car was when I bought it in August of 2017:

First day:
https://www.miataturbo.net/attachmen...1&d=1701966817
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The previous owner left a host of receipts of various autocross events it was taken to. Mods were lowering springs, sway bars, intake, NB2 header, an aftermarket muffler and what seemed to be a homemade rollbar. I think the rollbar was more of a mouse trap. Someone had removed the CEL to hide an EGR/MAP sensor code, and I fell for it. Got the thing for $3800 and some oil leaks, so I didn't mind. Believe me when I say this muffler was quiet but sounded good. The large tip was just for looks haha.

At this point I just put many miles on the car. It was my daily driver for a year until I moved to New Mexico and it stayed behind for a while. I even considered selling it at this point in time. I had made no further mods, just maintenance (plugs, wires, timing belt, water pump, etc.) and my philosophy at the time was to keep it a fun daily driver.

https://www.miataturbo.net/attachmen...1&d=1701966817

After a year I found myself wishing I had the fun little daily driver to enjoy in the mountains, so I drove it across the country on 06/23/2019:

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At this point, I had broken the engine in the Stealth being an idiot. You see, two step is not very good on some valvetrains. Improperly installing rocker arms is also not good on valvetrains. The Stealth was my weekend fun car, and now the Miata had to take that role until I rebuilt the Stealth.

I proceeded to just enjoy the little big Miata for a while, driving it after work and on weekends. I even got to park behind the one that started it all for Mazda at a cars and coffee event:

https://www.miataturbo.net/attachmen...1&d=1701966817
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I'll end this post here and start a new one. But it was at this point that the mod bug took hold, and the build began.

Clean looking car! Looking forward to seeing the rest of the journey.

I always had the pipe dream of taking my car on a long road trip to somewhere a few states over, hitting some killer roads along the way. However, that ship might have sailed as my car is no longer super comfy to drive for more than a few hours at a time :rofl:

Scooter?!

That brings back memories of a sorta similar car here called Scooter, and its now-departed driver.

Keep up the good work!

Thanks! More to come, but may need to call it done for today after the next post.

I hear you on the lack of comfort. In its current state it is tough driving this car more than 2 hours without stopping. But I still do it for a killer road trip to Colorado or through northern New Mexico every once in a while!

Oh, sorry! I hope it isn't insulting. The car is called that because my mom called it a "chivichana", a sort of cuban home made scooter, so it stuck.

At this point it was 2020, the Miata is in New Mexico, and the mountain roads were really showing how bad the suspension was. The car was scraping the fender liners in hard corners, and sometimes felt unstable over bumps when going fast. Not to mention smacking the bump-stops was a normal occurrence. I was also seriously wanting to take it to the local track.

Out of nowhere some unfortunate events happened to a friend's NB, and he sold me his OEM hardtop at a good price:


https://www.miataturbo.net/attachmen...1&d=1701967136


Another friend of mine convinced me to buy what I would consider to be the component that began this build; A set of Xida coilovers. I couldn't find any pictures of them when they arrived, because I installed them that same night. I know I took one, but it's lost to the digital gods. That happened around May of 2020. From then on things progressed quickly (for my pace that is). To improve the driving experience, the car got Xida race coilovers, PacoMotorsports strong arms, a center console delete, carbon fiber Lotus seats, a lowering bracket for the driver seat, and the A/C compressor left the chat. I also put its first nice set of tires on, some Continental ExtremeContact Sports and removed a few other bits to reduce the weight some.


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After that round of mods it was a hoot on the mountains and handled amazing. No longer did I have to go wide on some corners to avoid a dip, and found myself testing the limits. Friends and I penciled June 26, 2020 for a track rental and off I was....to fix some oil leaks. After some torch action on the crankshaft sprocket, a sacrificial two jaw puller, and many rounds of cussing, I was able to replace that front crank seal, the timing belt and water pump. Also at this time I did the usual things for trackday prep, like oil change, brake fluid flush, and getting psyched!


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Scooter was ready, but the cat wasn't impressed.


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Next up was trackdaaaaaaaay!!

Trackday arrived, and friends and I went to Sandia Speedway. I had hundreds of hours in a racing simulator and was feeling confident. Went out on my first session under instruction of my friend, and after two hotlaps was feeling like Ayrton Senna at Donington 1993. Going through the backstraight feeling like hot stuff, blew through a braking zone, unloaded the rear and spun the car off the track. It stopped by the grace of a dirt trap. I wish I had a video of this, because I only remember a wave of dirt and dust going over the hood and into the car. But I do have pictures of the aftermath:


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The only damage was to my ego, and after a pep-talk, dusting off the car and my shame I got back out to the track and started learning. It quickly became obvious that the Continental ExtremeContact Sports are not track tires, and I kept overdriving them (later I would find that I had flatspotted one!). Fast forward a few hours and I'm trying to set my fastest lap of the day. You'll want audio for this one:





I couldn't believe it. What a manus. The engine didn't sound happy and started to stumble. It cleared up after a while, and then it stalled in the pits. FAK. After making sure no rods had escaped and checking the oil dipstick for metal, I started it and it idled. I began the drive home and the car leaves me stranded every 15 minutes. I'll cut to the chase, the CAM sensor had died and somehow kept overheating. My friend drives an hour and a half to pick up the only one I found in the vicinity, then captured this picture of an idiot fixing his Miata on the interstate. The rest of the drive home was uneventful.

https://www.miataturbo.net/attachmen...1&d=1701967617


I spent the night researching what happens to a stock BP at 9k RPM. This one had survived, but from this point forward there was a notable oil consumption issue. Regardless, trackday was a blast, and I couldn't wait for more. The Xidas were amazing, but I could tell the suspension needed more work, and could feel a fair amount flex in the chasis. Next up I ordered some FM frame rails and butterfly braces, SADFab bronze bearings, poly bushings, Supermiata radiator, FM coolant reroute, Blackbird GT3 Rollbar, and Toyo R888R tires.

https://www.miataturbo.net/attachmen...1&d=1701967685

I'll speed forward a bit. Now I had a plan and vision for Scooter; it was to follow the "slow car fast" ethos, but I wanted it to be a little different, and teach me. Like most around here, I always wanted to turbo the car (I'm a Mitsubishi fanboi after all), make 200+ whp on boost, but it was around this time that I became interested in Webber carburetors and ITBs through the same friend that introduced me to Miatas, to trackdays, and to the Xidas. I'll leave this post at a progression photodump.


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Might just be me but the photos aren't showing up. I wanna see the car filled up with dirt!

Money shifted my stock motor above 8k rpm a couple times too, luckily without any notable effects as it was leaking too much oil to tell if it started consuming some as well.

Seems you were progressing the car at record speed during this point in its life!

It wasn't just you. I had removed the attachments to attempt to cleanup the thread some. The images were cached for me so I thought it was working, but turns out it wasn't ok! I just re-added them all. Try a hard refresh (CTRL+SHIFT+R) and let me know if it's working now, please.

They are workin! I saw them broken this AM too, they are def back and working now.

Love the thread man! Ricardo is a great dude, an awesome tuner, and a good driver! Keep the posts comin'!

I'm glad I'm not the only one that made the BP scream like a B18 at least once! My soul still hurts watching that video.

Glad you think so. I was struggling with motivation and confidence during this time after damaging the Stealth's engine. Luckily my car friends kept pressuring me to continue.

Sweet! I'm glad the pics are back.

Thanks Nate! That means a lot. I'll post the next steps tomorrow. MS3, another trackday, and peer pressured into doing the ITBs right after a car meet.

No way, he would be chuffed to read this thread!

So that was a 5->6 change that got 4th instead? BTDT, mine survived unscathed. The over-rev probably didn't do anything if the rods survived, but if you are going to work that engine harder at least do a quick and very dirty check on them without lifting the head.. See my build thread for my method, it only compares the height of the paired pistons but better than just crossing your fingers and hoping ... these rods are weak.

Yeah, I spun on my first lap with the instructor beside me, after him showing me Race Driver 101 for three laps!! His comment was 'At least you are trying', not sure what he was actually thinking though - couple of decades later our paths crossed again, and we had a laugh about it!

phew. I'm glad.


It was a 3->4 that found 2nd. I'll check out your method and give it a shot, but at this point the motor will be out of the car by next season to make way for a BP-6D. More on that later. I've avoided doing a compression and leak down test on the engine because I'm afraid of what I'll find, and it just kept running for years and thousands of miles later.


haha, that's awesome. It's good that you got a laugh out of it later. My friend and I still laugh about it too.

Nice looking car! I'm excited to see another ITB build. What brand are the ones you have? They don't look like Jenvey, BBR, or OBX.

Thank you! These are Borla Induction Series 2000 ITBs. Previously known as TWM Induction.

Had to go rummaging through old drives to find more pictures of this stage, so here we go.

Shiny ITBs are sitting in my table, and an MS3 is calling. I start researching how to get it all put together and running, and come to the conclusion that there is a world to learn. Fun and exciting. First I decided to install a shorty console and relocate the window switches to it. I had previously installed a set of LRB aluminum door cards as well, and deleted the radio and speakers.


https://www.miataturbo.net/attachmen...1&d=1702433268

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Next up was the MS3 install. I won't lie, this was a pain to get installed. The instructions made it seem like it would just go in the stock location and use the stock mounting holes, but that wasn't the case. The singular motorsports mount was awesome, and with that out of the way, the car started on the first try! Nice.


https://www.miataturbo.net/attachmen...1&d=1702433360

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I spent sometime learning TunerStudio, MegalogViewer HD, MS3 and tuning fundamentals. Some tunings later, it was off to the track again. Big thanks to my friend Kristina for running around the track taking pictures!



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This trackday went very well. I had small off-track excursions, with the worst damage being a bent butterfly brace, and the coolant hit over 230F at least once. Laptimes were ok, around 1:39 to 1:42, but the car was fun and I was revving it to 7500RPM already. The tune was a mess. The car ran and idled, but it was rich at the lower altitude, and lean at higher altitude, and had different running states between cold and heatsoaked. I won't go into too much details, just know there was a lot of work to be done but I was stoked that it had no major failures!

Right after I installed a SuperMiata radiator, FM coolant reroute, and deleted the MAF. Took the car to the local meet, and got peer pressured into starting the ITB install that day....


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I didn't take many pictures of the specific modifications that had to happen to fit these, but from what I remember:
1. Bend the fuel feed line slightly to allow space for the air filter
2. Shorten and resolder throttle cable
3. Modify throttle cable adjuster (provided by Borla) to fit the Miata cable
4. Cap stock injector ports at the head
5. Modify wiring to use a new TPS and reroute other wires (e.g grounds)
6. Mount a vacuum block for the MAP signal and brake booster

After all of these mod and a modified tune, we said screw it and gave it a crank:




The damn thing started on the first try again! I was so happy. Big shoutout to my friend Richard for letting me use his shop, and helping me get these mods done. It took one week of afternoons to get the car started. Richard wasn't happy with the other side of the engine bay, so we decided to install that sexy ISR header. It took some grinding and cutting to make it fit the mid pipe, but the end result looked really cool:

https://www.miataturbo.net/attachmen...1&d=1702434006

I'll stop this one here. This was around June 26, 2021, and from then on began the tuning, more learning and issue discovery phase of ITBs. The next goal for Scooter was to make it to its first cars and coffee and another trackday as an ITB Miata!

Awesome, that ISR header really does (did) look cool aye?

Love the pics you dug up, and love that first start video. The manic cackling is hilarious, and I love it.

It really did look cool. Unfortunately, the craftsmanship didn't hold up, and it had a very bad resonance that travel through the car around 3600RPM, which is probably what cracked it.

Hahaha I'm glad you liked that. I was so happy when it fired and I heard those snorts for the first time!

It's almost been a month already! So next in the saga was getting the car tuned. ITBs are very finicky, and cannot be tuned using Speed Density. Alpha-N is the only reliable way to tune an NA ITB engine so I had to learn that method. Megasquirt has a cool tuning algorithm, called ITB Mode that blends SD and AN into one table, and that allows the best of both worlds. SD while idling and cruising, and AN during higher loads! The tricky bit was to learn how to setup ITB mode, and to gather all the data I tuned the car on a Hybrid Alpha-N setup, went to a trackday and gathered a couple of hours of different load areas. Right away I could tell something was very wrong with the tune though. Idle VEs were around 88, and the car was pig rich during warmup (10 to 11AFR), and fixing warmup messed up the running at operating temperature.

A few pics of the first time I took it out on a weekend cruise:

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A few pics of the first trackday. There aren't many because I spent the whole time looking through the data and learning. Something I enjoyed was watching the header change color week after week. Sorry about the dirty engine bay on these....I may have confused Scooter for a rally car during this trackday.....

https://www.miataturbo.net/attachmen...1&d=1704829312

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All the while I was chasing my tail on the warmup issue, the idle SUCKED when cold and I had to feather the throttle when coming to a stop to keep it from stalling. If there is anything you learn from my journey is that ITBs without an Idle Valve are a PITA to live with. But for the next 6 months or so I just kept learning how to tune the damn thing, and was loving the noises.

At some point in 2022 my friend Tim pitches the idea of going to Flyin Miata summer camp. At first a trackday was mentioned, which was later changed to an autocross. I wasn't stocked on the idea of autocross, but a road trip to Colorado sounded like a great time. Just a few issues to address, my suspension bushings were looking...expired, and I couldn't stand the idle issues anymore. I also had been thinking of installing longer trumpets and see what difference they made. So Tim made me an aluminum bracket to install an NB Miata IACV, I got busy designing and 3D printing some Carbon Fiber trumpets, installing SADFab bronze bearings, new alignment and more tuning!


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Unfortunately that's as much camber as the front could do. I knew I wanted more down the line and started researching extended ball joints, but that was a project for a later time. At this point I had also removed the power steering and was recommended to run that much caster to help the return to center and the steering effort was considerable but not unbearable. On the next update I'll add pictures of FMSC and the next trackday for the car!

Loving reading this thread. The and thoroughness and abundance of photos are greatly appreciated.

Have you run less than 6* of caster without power steering since the first alignment? I was never able to produce less than 4.7* with my current setup but never had an issue with steering effort. I remember being nervous at first because it seemed like the general consensus was that you should run degrees of caster or even a hair less if possible.

Excited to hopefully see the carbon trumpets on the next post!

I'm glad you're enjoying it! I'm doing my best to find pictures in order.

Yes, I've ran less than 6* fairly recently while I was testing different alignments. I tried -3* camber and 5* caster which was nice on the street with no return to center issues, and the car was palyful. On track it oversteered and locked the front brakes fairly easy. I could have fixed that with sway bars and adjusting the brake bias, but I decided to re-align instead because the tire wear was rough and it sees 200miles of road just to get to a track. Now I run -2.56* camber and 5.5* caster which made the car neutral as I expected based on my saw bar settings (rear is set at the middle, front isn't adjustable). I can make the car oversteer if I try which is great, steering effort is still considerable but I don't mind it. I based my alignment off the supermiata specs for dual duty, and my alignment mechanic's recommendations for the caster, so far the tire wear in the last two events has been great and tire temps were good too.

The carbon fiber trumpets are in the last picture above! They're not weaved carbon like you might have expected because they're 3D printed. I used a carbon fiber polycarbonate filament from Prusa: https://www.prusa3d.com/product/prus...-black-800g-2/

Link to print: https://www.printables.com/model/453...hrottle-bodies

Next in the timeline was Flyin' Miata Summer Camp 2022! With the car aligned, an IACV, and new trumpets, it was time to get some stickers! These arrived just in time and I recon it was 1% HP gain per piggy!

https://www.miataturbo.net/attachmen...1&d=1705072813

Also, this is how these trumpets sounded now:



Scooter was washed and ready for the 10 hour roadtrip! and the majority of these pictures were taken by Tim.

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At one point we were going around a U-Turn in an insanely fun section of mountain road and Tim pulls over to take this picture. A favorite of mine.

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On our way to Ouray, enjoying Million Dollar Highway, we came up on a group of RVs parked at a pullout. We had a set of radios for communication tuned on the walky-talky band and heard them say "Check out these MX-5s coming up. That must be so fun!". Yes dear stranger, it was a blast!

Stopped at Ouray for a break. No A/C and manual steering was doing a number on both of us. This was on a very hot day for Colorado. I had never felt a chassis heatsoak and radiate heat like this before....

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We eventually made it after many insane elevation changes, fantastic vistas, and neither car skipping a beat!

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The next day was autocross, in which neither of us were going to participate in. We went by to spectate for a bit, then went downtown to checkout some art and museums. Later that day was a cruise through Colorado National Monument. I'm really bad at taking pictures so this is all I have from that afternoon, and neither of these were taken by me....

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The last day was the meet and greet at the FM Headquarters, and I was stoked for that. It was such an awesome day meeting fellow enthusiasts and all the FM staff. I got to chat with all of them, at least for a little while and can only imagine how exhausting that can be for them. At any rate, I learned a lot and made great acquaintances. A gentleman that was driving in-front of me through the National Monument said something about "the exhaust of the car behind me sounded really nice through the tunnel, and it was loud!". I don't remember if I told him it wasn't the exhaust haha.

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That last picture is also one of my favorites because it reminds me how accomplished I felt after getting Scooter all the way to Grand Junction and back on what was a very homebrew tune, and my first standalone ECU. We had both come a long way! The drive back home was very fun, and the next mods were already in boxes at home. The engine was consuming around 1QT of oil per 400 miles at this point.

I keep having issues with pictures unattaching if I take long writing a post. Any suggestions on how to attach pictures better?

Ahhh mega derp on my part. I should've looked closer. So cool! I envy the guys who have the ability to make/3d print one-off parts for their cars.

Great feedback on the alignment. I'm with you in regards to high camber and having to drive long distances to wail on the car. My car's had 3*+ of camber in the front for over a year and I was driving nearly 200 miles to the track before I started towing it. Getting to the canyons from where I live is a 50+ mile drive minimum as well. Felt so wasteful killing my inner edges with all that mileage just to go rip the car hard lol.

Road trip looks like it was super fun, albeit a little bit hot haha. Looks like you guys covered some solid ground! My buddy and I are actually toying with the idea of driving out from Cali in July to race Global Time Attack at PPIR. We'll be passing through Grand Junction via the 70on the way. Any must hit roads you remember from that trip? The one near Colorado National Monument looks pretty sweet on Google Maps.

I've also noticed that pictures seem to disappear if I start a response on here and leave my computer for a few hours. No clue how to get around that...

Thanks! It is fun being able to make small parts. Lately I've been making GoPro mounts for the Blackbird bar, and designing a mount for my external GPS too. If you have something in mind shoot it my way and I'll give it a crack!

Highly recommend doing that drive, if anything just for the experience. There are a lot of awesome roads on the way to and around Grand Junction, but I don't know if they would be on the way for you, since we launch from New Mexico. Off mind, going through Grand Mesa was bananas, Million Dollar Highway (US550) between Silverton and Ouray both ways, and Colorado National Monument is a must as well. One of the most fun road I've driven was CO-92, the closest end to US50. It has great twisties, sweepers, U-turns, straights, great views and super smooth. There is a beautiful lookout/rest stop that I highly recommend, Pioneer Point. But there are so many awesome roads in Colorado that you could chart a route, look for paved backroads around it and likely have a blast in the Miata. As long as they're paved :D Sometimes the driving isn't mind-blowing, but the views are.

Heck yeah dude, love to hear that! I was gonna say, it seemed like the 550 would have to be your guys' route. I've only been out that way when driving from Moab to Durango a few years back. That was in a Ford Econoline van, though. Definitely not the most fun canyon carving vehicle.

Maybe we'll detour and unload the cars to drive the 65 to Grand Mesa then. Silverton to Ouray looks incredible but is probably a bit out of the way. Same with the 92. All of those roads look insane though! So many awesome routes you could put together through there. Agreed on the views as well. I've been to Aspen and Vail a few times in the summer and that whole stretch of mountains along the 70 looks like it's straight out of a Hallmark postcard. Jealous you guys got to drive through hours of that in the Miatas.

Funny you'd mention the GoPro mounts on the rollbar. I've actually been meaning to pick one up for mine. They're for a 1.75" OD? If so, I'd happily buy one off of you!

yep, 550 is a constant for us. There was a lot of traffic and construction on our way back in 2023 which was a bummer, but still great views. Ha, it is a much different drive in a Miata than a van! You'll like Grand Mesa though. It's scenic and fun. I-70 does have awesome views too! It's wild how beautiful different areas of the US can be.

Shoot, that's cool. Yes, it is for a 1.7" OD bar. My bar is closer to 1.77" OD (45mm), but the print is slightly larger to allow a felt or rubber insert that prevents marring and helps with grip. I'll send you a PM, and if you like it, maybe buy me a coffee or something.

Seriously wild. I remember the Pacific Northwest having my favorite views in the US until I visited central CO in the summer. They're pretty damn close now haha.

And sweet! That's perfect. I usually slap a little mastic tape on the inside of clamp mounts to dampen vibrations. Seems to make the GoPro rely less on image stabilization. Ill buy you two coffees for your trouble.

Redursidae, love a good ITB car. The thought of ITB'ing my car crosses my mind several times every day.
However your thread is so far lacking a video with driving ITB sounds, only idling. I demand driving :D

Hi hello, I'm still here and so is that Scooter... and tbro is still around if thats who you meant :D

Good to see you here SD, I'd heard you had Scooter - not been washed away yet?! Yeah seeing the name brought back memories of Slammer and his exploits, especially at Wakefield - that has to be 20 years ago now!!!! Did you buy it from his estate, or later (from tbro?)? All that stuff has disappeared from the forum, so hard to trace things when they crop up again.

Thank you, and you’re correct! The truth is that most of the videos I have pre-2023 don’t make it justice, and usually were very shaky. I promise some are coming in the next update, including a 7400 RPM flyby at the track!

I’m very curious to see your Scooter though! Do you have any pictures, videos or build thread to share?

The next milestone after FMSC 2022 was taking the car to the track again. This time it had fresh suspension, a good alignment, and felt good overall.

There were a few notable things this day:
1. I had a sparkplug come loose on the way to the track. I noticed the car was knocking a lot, took off my earplugs and heard an odd popping noise. Tightened the plug and saw no damage from this.
2. Had a LOT of knocking going on at the track. It was good data because it showed my sensor and configs were working. But it wasn't because of ignition advance, instead it was lack of fuel! Later on I would learn that the Innovate wideband was reading richer than actual because of voltage offset, and I almost popped this motor trying to get some fuel economy. It also explained why I had to idle at 14.0 instead of 14.7....
3. Got to drive around the track with a Yamaha R6 and also chase my friend Tim. Lots of fun this day.

First to address the lack of driving videos!

7400 RPM fly-by:



Chasing Tim around Sandia while trying a new line:



I supposed I haven't mentioned the exhaust in the car much, but it is a stock replacement unit from Rockauto, sitting behind a cobalt midpipe with a catalyst. I had a local shop cut the cartoonish tip off the muffler Scooter had and put it into the Rockauto unit. Likely a restriction, but I was after a quiet exhaust so that the ITBs is all I hear. Trust me when I say that it is loud in the cabin at WOT. For comparison, the sound the GoPro gets is roughly what I hear in my helmet.

A few more pics from the trackday:

https://www.miataturbo.net/attachmen...1&d=1705350035

https://www.miataturbo.net/attachmen...1&d=1705350035

https://www.miataturbo.net/attachmen...1&d=1705350035

After this trackday I wanted a way to keep an eye on AFR, Coolant and eventually Oil Temps without having my tablet plugged in. I also decided I wanted a CAN based wideband controller. I installed a CANChecked MFA 2.0 where the oil pressure was in the dash. Also ordered a Spartan 3 controller, and an FM 10" LBBK!

https://www.miataturbo.net/attachmen...1&d=1705350035

https://www.miataturbo.net/attachmen...1&d=1705350035

https://www.miataturbo.net/attachmen...1&d=1705350035

https://www.miataturbo.net/attachmen...1&d=1705350035

Unfortunately, this is also when issues began to surface all at once, and the car wouldn't see another trackday or much driving the rest of the year. I also had to drive the Stealth to Florida and get that project going after years of ruminating and dreading it.

Not Miata related, but turbos are cool!

https://www.miataturbo.net/attachmen...1&d=1705350309

https://www.miataturbo.net/attachmen...1&d=1705350309

Ah that sweet sweet sound :)

I’ve got a thread here for my car, it’s been a bit since I updated so I should: https://www.miataturbo.net/build-thr...another-89305/

Awesome stuff, that ITB sound is always incredible!

I need to look into that multi function gauge display. Seems like it'd be a lot neater than adding a bunch of extra gauges. I am not sure how much I trust my 34 year old NA6 oil pressure gauge I swapped into the cluster, and having an oil temp gauge in one of the AC vents is not ideal on days where I really want the AC on max.

I took a read through your thread and really like your car. It sounds very nice! Would love another update on it soon.

Thanks! They sure make driving the car fun.

It's a CANChecked MFA 2.0 for MX5; I recommend it. This one worked great on MS3, but unfortunately has a bit of trouble with the Link G4X I run now. CANChecked support sent me an updated firmware that fixed most of the issues, but the shiftlight is buggy (flashes continuously) when it activates, so I turned it off. The new version adds WiFi, an updated UI, fully configurable CAN stream, and CAN switch capability, which is very tempting. But this one is doing its main job well for me, and I could spend the money elsewhere for now.

Winter 2022
 

As I mentioned in the last post, the end of 2022 was tough for Scooter. I had issues show up one after another, and wasn't able to track the car or drive it much by the end of the year. This post won't be in good chronological order because I rather mention the issues and how I fixed them.

Issue #1: Fuel pressure drops and fuel leaks

From day 1 of installing a fuel pressure sensor I noticed that fuel pressure was dropping to ~48 PSI at full throttle, sometimes as low as 45psi.

https://i.imgur.com/USrmpBr.png

I asked shops and people around and was being told this is normal with large injectors on a returnless fuel system. Mhmmm, odd; but these injectors are not being worked hard, and if so, how does the ECU account for this? MS3 doesn't use the fuel pressure input to change pulsewidth, but when set to "returnless" it does change it based on a calculated differential fuel pressure. But I just had a feeling something was wrong with the hardware. One Friday I was letting the car warmup to go to work when I start smelling fuel out of the engine bay. Lo-and-behold there was a massive fuel leak from the pressure regulator attached to the fuel rail.

https://i.imgur.com/U7GHW8U.jpg

This regulator was provided by Borla, and although not used in this system, they told me to leave it in place with no vacuum reference, so I did. I contacted Borla, and they sold me a block off plate to eliminate the regulator. They also sent me the wrong bolts for said plate. I got some at the store and bolted it all together.

https://i.imgur.com/AR3rSYs.jpg

With the regulator blocked off, the car started and the leak was fixed. I went out for a drive and it was bucking like a horse at part throttle ~3.2k RPM, but was fine at WOT and idle. What the hell.

https://i.imgur.com/vY9ibqI.png

A quick peek at the datalogs showed the fuel pressure was fluctuating wildly at part throttle (Peak of 63, valley of 38 PSI)! But held closer at idle and WOT. BRUH. This may not be nearly as noticeable in a plenum setup, but with ITBs the pressure caused by the short runners does weird things, and differential pressure moves around a lot. Right away I knew the fix was to add a fuel pressure damper, and this means that the regulator was acting as a damper. Some googles later I found this adapter from radium engineering that allows the stock fuel pressure damper to be installed.

https://i.imgur.com/4DEUXLz.jpg

https://i.imgur.com/0ROYxJQ.jpg

BUT, yours truly had gone gorilla on the AN cap at the end of the rail, and ganked the threads....nice. I bought a tap to rectify the threads and sent it.

https://i.imgur.com/Hju2EiF.jpg

https://i.imgur.com/vWW0mVS.jpg

https://i.imgur.com/BqX7Tx5.jpg

Took the car out for another drive and the issue was fixed! I didn't find any datalogs from the results, so I'm sorry for that. But what is that noise when I hit a bump?? And why does it go away when I brake?

Issue #2: Play in Bushings?

A couple drives after fixing the fuel pressure issue I start noticing a noise coming from the left rear suspension. It went away touching the brake while driving, and it got worse with bumps or when the rear was unloaded. The car didn't feel weird, but it sounded serious. Checked all bolts, and all was torqued to spec. Checked for play in the bearings and WOOAH dude, what's that? The RLCA bolt was moving. I could actually move it with my hand up and down, side to side. FAK.jpg . Disassembled the bushing to find this:

https://i.imgur.com/NYyPZfX.jpg

I contacted Sean @ SADFab, and he said this could be caused by something being loose, or the spindle having play. I promise all was torqued to spec, and the spindle doesn't have any oddities going on, but he didn't know what would be causing it otherwise. Maybe I screwed up something in the install? At any rate, I decided to swap the orientation of the bolt, and swapped the sleeves with the right side. I also remembered I hadn't greased these in a while, so decided to do that too. After some fumbling the issue seemed fixed. 1 year later, and the play hasn't returned. If any of you have any insight or suggestions as to what caused this, I would really appreciate it.

Issue #3: Brake fluid leak

Around the time I took the car to FMSC 2022 it sprung a brake fluid leak by the rear calipers. It seemed to originate around the hand-brake adjusting bolt. Not having a lot of time before the trip I bought a replacement set from Rockauto and got that fixed. Unfortunately, the Rockauto ones started seeping fluid from the same place....but I realized it only happened when I used the hand brake. Really weird. I was already planning to install the FM LBBK before winter, which would delete the hand brake, so I began getting used to not using it. It was time for some nicer brakes (and less weight!), so on went the FM LBBK!

https://i.imgur.com/K6TUxhD.jpg

Issue #4: Warmup, Cold Idle, and Weird VE Table

Since day 1 of installing the ITBs and the DW550 injectors things just looked very weird with my VE table and the warmup was overly rich, even with 100 in the WUE table (around 20% richer with no WUE). In addition, the cold idle wasn't great even with the IACV plumbed to the vacuum manifold, and I had to help the car idle for a couple of minutes in a cold start. DIYAutotune support wasn't able to help me with the VE issue, and DW told me the injector data provided was correct. This warmup issue made me really want closed-loop EGO during warmup, but MS3 doesn't have a nice way to change AFR target at different coolant temps or engine running time. In hindsight, I should have ran closed-loop EGO anyways with a long post-start delay. But even more in hindsight, the injector data was/is very wrong. I'll mention more about the tuning when we get closer to current times. I was tired of going in circles with this issue, plus wanting more OEM functionality and future expansion made me want to get a Haltech or Link G4X.

Here is what the VE table looked like by the end of 2022:

https://i.imgur.com/R9U75t9.png

After some emails with Kris @ KORacing (and lots of research) I ordered a Link G4X NB1 plugin. One live session later he had setup really good injector data for Scooter. The tune became much more predicable since then. There is still some richness going on at cold idle which I'm chalking up to the odd IACV plumbing, phenolic intake gasket, and DW injector behavior when cold, but it isn't anything that closed loop EGO can't take care of. I'm very thankful to Kris for his huge help.

A few pics of the Link ECU and what the VE table became once I tuned the car in 2023. One thing to note is that this VE table is Hybrid Alpha-N, compared to ITB mode in the MS3 table above. Some of you may notice something was still very wrong with the Link VE table.

Pretty board
https://i.imgur.com/7MdkUa7.jpg

https://i.imgur.com/gQnYrBZ.jpg

USB Connecton and CAN Bus 1
https://i.imgur.com/28qfTon.jpg

The expansion looms for extra digital, analog, and temperature inputs.
https://i.imgur.com/RB3oIEx.jpg

MAP line, and decided to put CAN and USB to the rear
https://i.imgur.com/hEe1LEr.jpg

Connected to the ECU for the first time. Yes, it was 6 C in the garage.
https://i.imgur.com/YV4gYwb.jpg

VE Table by the end of 2023
https://i.imgur.com/uYPVsBC.png

This was it for Winter 2022. By March 2023 Scooter was running well, cold starts were much improved, and I was enjoying learning a new ECU ecosystem. The setup at the time was Link G4X, Spartan 3 wideband controller (CAN input), fuel pressure sensor, and the usual other sensors to run the engine.

Yes...one of us! One of us!

Kris is great, I've been working with him since....many years. He helped me understand the limitations with MS, and convinced me to switch to Link after tuning a number of MR2s, BMWs, and then some Miatas on the G4x platform.

Quick hint, you can right click on your fuel table and click "reverse load axis", and it'll look more like a MS table, which I still prefer.

haha yes. I've enjoyed the G4X and wish I had installed it sooner. The manual alone is worth everything.

Thanks for the hint! I should use that for the comparisons here on the forum as most people are used to seeing the power row on the top. Going to update the picture above.

ABQ Super Lap Round 1
 

For 2023 I had a few goals for Scooter:

- Begin building (or finding) a replacement engine. The original BP-4W was burning 1qt of oil every 350 miles. With over 177k miles (a large portion being hard miles), and at least one 9k RPM overrev, what more can I ask of this little guy?

- Race in the local ABQ Super Lap time attack for the 2023 season

- Make it to Flyin' Miata Summer Camp 2023 and participate in their trackday

- Have fun and learn more car-tooning :D

So I got right to it and picked up a junkyard motor and spare 5 speed. No warranty, no returns.

This picture was actually taken in July 2022....the engine sat outside a while.
https://i.imgur.com/XwhSr1O.jpg

Finally on the stand in 2023
https://i.imgur.com/e9mBJWN.jpg

I went to turn it and it was seized. :doh: I had checked it at the junkyard, so I guess I caused it by letting it sit outside too long. One disassembly later and 3 sets of piston rings were rusted, along with a few valves. Great. It was my first time tearing down an engine, so at least got that out of the way. The search continued.

Since I can get a bit dumb in competition, I decided to play it safe and got me a Schroth SHR Flex to go with the Schroth ASM harnesses. An MPI Mazda Cup wheel got into the mix with an NRG Keyway quick release and an MPI hub.

https://i.imgur.com/jx5qlPZ.jpg

https://i.imgur.com/h3SStbY.jpg

https://i.imgur.com/XVOI8Ex.jpg



I had wanted one of these MPI wheels since I first saw them in the MX-5 Cup Racecars. I love how it feels. It's a very ergonomic wheel and sets the mood really well ;)

Next, put the car on scales to corner weight it. First two pictures are no driver, and 3/4 tank of fuel
https://i.imgur.com/CLwM2QS.jpg

https://i.imgur.com/XnwpafW.jpg

Now with me in it and 3/4 tank of fuel. 50/50 cross, 51.4/49.6 F/R
https://i.imgur.com/xxQBAoc.jpg

Didn't have to touch a thing!

To keep the spark going, Scooter got a set of Denso COP wired for sequential ignition. I ordered these from GFB Development and were a breeze to install. This was the first start with them:


Zero fuzz on the ECU side, just two extra wires for the Coil 3 and 4 signals, change the ignition dwell and tell the ECU to use Direct Spark. I can't say I've noticed any performance gain with these...but they look nice. I also didn't have to adjust the ignition offset, which was surprising.

And before the first round of time attack it was up to an oil change, greasing the bronze bearings, greasing the sway bar mounts, aaaand the Jongbloeds don't fit the LBBK. DUDE. I had forgotten to check the fitment an it's the night before ABQ Super Lap Round 1 :loser:

So on went the Konigs and the Continental Extreme ContactSports once more. Those poor poor tires.

https://i.imgur.com/bOCF17q.jpg

https://i.imgur.com/Khjg5pp.jpg

https://i.imgur.com/Nm0OYxx.jpg

https://i.imgur.com/GoA809v.jpg

Video of the time attack session that day. I had to go into this trackday with a test and tune mentality. It was the first time on track with the LBBK (the brake bias wasn't dialed yet), not on track tires, and first time with the Link ECU here too. Lots to learn. But it was a successful day, aside from flatspotting 3 out of 4 Continentals :noob: I'm heavy on the brakes....



The times were nothing to write home about: 1:39s (Spec Miata mid pack is around 1:35 to 1:36. A fast Spec Miata hits a 1:32), but I was stoked with the car and the event. Great community.

My father-in-law asked if Scooter could hit over 1G in the corners, and since one of the cool extras of the G4X is the internal G sensor, I threw some dots on a scatter plot to show him.

https://i.imgur.com/VYZB26p.png

Cats given out. Still enjoying reading the thread. The Link having a G sensor is a cool feature!

With your custom mount, did you have to crank the exposure way down on your GoPro to get footage from the outside of your car to show up? I used the mount you sent me for the first time yesterday and the angle came out spectacular! Unfortunately, I didn't mess with any of the camera settings and the footage came out all overexposed since the camera adjusts for the darker foreground of the interior. It's pissing rain here but I'll give it another go next weekend.

https://cimg5.ibsrv.net/gimg/www.mia...fc8dbc8ca0.jpg

Thank you, and glad to hear you're still enjoying it.

I haven't figured out the exposure issues fully yet, but yes I have to play with the ISO setting, and also try centering the frame on the outside to give it some help (I think Emilio said to do that in one of his posts). Checkout this video about the ISO settings: . Let me know what you figure out, because I still have to fiddle with it every time I use it, and more often than not I just forget to configure it and have overexposed videos.

I should've searched for this video beforehand haha.

I'm currently running a first-gen Insta360 cam, and the automatic exposure it selects is entirely up to positioning rather than orientation since it's recording everything around it at once. I'll have to see if I can manually dial in the settings a bit better. I also have a GoPro Hero 5 session (the tiny one), that I've used a handful of times with varying success. I remember having to dial down the exposure to avoid blowing out the exterior view, and could usually get the interior pretty visible unless it was a cloudless midday session in the desert and was super bright out.

I'll mess around a bit and report back. At any rate, the footage is gonna come out awesome with the new angle once the camera is dialed in!

Haha no worries. I like how your camera shows your feet in that angle; my GoPro doesn’t catch the feet well in that angle. Maybe I should snatch one of these Insta360s. I guess they use the same mounts as the go pro then? That’s cool.

And glad you like the mount! Let us know how the settings work out

Heck yeah, it captures all the footwork and even the water bottle mount! What more could you ask for haha.

I'll keep you posted. Excited for the next update on the car!

ABQ Super Lap Round 2!
 

Since the junkyard motor was seized, I started looking for alternatives. After quotes from local machine shops, it seemed that swapping to an used VVT motor would be more cost effective for now.

I also ordered a Fluidampr harmonic balancer and a 36-2 trigger wheel from Supermiata, hoping that it would help with some of the harmonics at high RPM for the "new" engine build, which I want to rev to 8k eventually. Buuuut I couldn't let it sit around until then, so it got installed right away. This was a straighforward process, remove old balancer, install new balancer with new trigger wheel. Set the Link to use the MX5 36-2 , and set base timing. I did have to fiddle with the sensor air gap a bit.

https://i.imgur.com/edrjK6y.jpg

https://i.imgur.com/SR86Eib.jpg

https://i.imgur.com/HfTHR1P.png

https://i.imgur.com/do8doKv.jpg

The 36-2 trigger gives the ECU a lot more resolution which caused the idle ignition control to react faster. In the Link G4X, idle ignition is done by a closed-loop PID algorithm that looks at idle speed (instead of a correction table). With the new resolution, the engine sounded a bit "different" at idle, so I decided to reduce the Proportional. I first made it 0.5, but later found that 1.5 was fine and much quicker reacting.

The engine had less vibrations at higher revs with the Fluidampr, but meh, splitting hairs. Scooter runs Mazdaspeed (or Mazda Motorsports?) harder rubber mounts, so vibrations are present at idle no matter what. In the Stealth a Fluidampr balancer made a huge difference in reducing vibrations at all RPMs.

https://i.imgur.com/7bxGi6B.png

The next trackday went without a hitch. The Jongbloeds went on with Accelera 651 Sports. Scooter made the drive there and back with no issues, and we set a new personal best of 1:37:752! I'm horrible at remembering to take pictures, so my apologies for not having much else to share other than this video.



I wouldn't be able to participate in the next two Rounds of ABQ Superlap, but the next big milestone was to go to Flyin' Miata Summer Camp 2024 and do a trackday there!

Love the rigged spark plug wire for the timing light hookup haha.

I noticed a large decrease in vibrations on my stock engine after throwing the fluidampr on. Wonder how much of it was just the stock damper being out of balance though lol.

That lap looked clean man! Seems you were getting more and more confident as well!

Haha, yep it's a good trick to make sure you get good base timing accuracy with COPs.

That's good to know. But true, one has to wonder how much of the improvement is a borked OEM damper. Both of the ones I replaced had a chip somewhere in the radius :eek3:.

Thanks! Confidence building was the name of the 2023 year for me. I'm glad it shows in the video a bit. It doesn't come across well, but every time I pass by turn 14 (the last corner) I take a deep breath and send it. The later videos will have telemetry though. Stay tuned for that!

Flyin' Miata Summer Camp 2023
 

With sights on Flyin Miata Summer Camp it was time to do some wiring. I had wanted to get oil temperature and pressure sensors for a while to play with more data. Bosch makes a combined pressure and temperature sensor that seemed awesome so I bought something like this:

https://i.imgur.com/7Y8BiBZ.jpg

I decided to install it in the stock oil pressure sender port, which is 1/8 BPT thread. There are quite a few 1/8 BPT to M10x1 adapters on Ebay, so I snatched a brass one.

For the sensor you end up using 4 wires; 5v, sensor ground, pressure and temperature signals. The Link G4X Xtreme (what the NB1 PnP is based on) has 4 dedicated temperature inputs (IAT, ECT + 2 spares), so I ran the temp signal to one of the spares, and the pressure signal to a spare analog input.

https://i.imgur.com/CM9MSep.png

https://i.imgur.com/BjhZg2c.jpg
Oil Temp now in the CANChecked gauge. Pressure is there too, just not selected

Now with more data, I went ahead and setup the RPM Limit to use oil temperature, and setup an oil pressure safety too.

https://i.imgur.com/NnZziSx.png

https://i.imgur.com/qI25NVB.png

With that setup, went for a drive through the Jemeze to try it out!

https://i.imgur.com/SGHvVcH.jpg

https://i.imgur.com/Qte8lxm.jpg
To celebrate, I took Scooter on a mountain drive.

Not long after it was time for Flyin' Miata Summer Camp, and a trackday at Grand Junction Motor Speedway. WOOOOOOOT!

https://i.imgur.com/q9OecYc.jpg

https://i.imgur.com/r7xJzk8.jpg

https://i.imgur.com/8ZFk6hh.jpg
This is fuel

The drive was epic, but in proper fasion, I didn't take many pictures. There was an exciting moment when the car started running super rich and smelling of raw fuel. Turns out the fuel tank had gotten very hot, pressurized itself and started doing weird things to the fuel pressure. As a result fuel started spraying out of the EVAP tube :noes: I had to stop every so often to release the pressure out of the tank after big elevation changes. I bought a corc plug at a hardware store and capped the EVAP line for the time being. My friend Tim was having a similar issue with his EVAP, so I didn't slow us down too much.

The trackday was the highlight of this trip. There were many cool cars and fast drivers in attendance, and NDs are really quick. My favorites were the Targa Miata and this LS3 powered NB. I got to ride in both V8 powered cars, which really messed me up for a few days. Check out those 275 wide hoosiers.

https://i.imgur.com/zbSYN8g.jpg

https://i.imgur.com/OOEzsmB.jpg

https://i.imgur.com/SrLnqfr.jpgV8 NB 3

https://i.imgur.com/cL7TbY6.jpg

This trackday was awesome. Grand Junction Motor Speedway is a blast to drive and it felt like a turning point for my confidence with Scooter. We finished 10th out of 35 with some really fast cars and good drivers around. Very happy with that.





The next day was the meet and greet at FM Headquarters. It's always awesome chatting with fellow enthusiasts, and the FM staff. Christopher had an issue with his alternator and needed a ride to get his trailer, so Scooter and I did a small roadtrip to help him.

https://i.imgur.com/2yApWeS.jpg

https://i.imgur.com/4x9zqU5.jpg
Take 2 of one of my favorite pictures of 2022

Remember how I said this was one of my favorite pictures of 2022? Well, had to do a retake. Now with a completely new ECU, running well, and nice suspension, Scooter was feeling dialed (but still burning 1QT of oil every 250 miles or so).

The drive back home was epic and with no mechanicals. We stopped after huge elevation changes for a break and depressurize the fuel tanks. Sights were set on the next round of ABQ Super Lap, and I had a few setup changes to try...

You Midwest guys are really making me bummed about missing FM Summer camp. Looks like a ton of fun! Cool to see you continuing to get more confident behind the wheel as well.

Did you end up removing the check valve(s) for your fuel tank vent that reside next to your fuel pump? I was having the same issue with fuel tank pressure buildup at high elevation on my car and found my evap check valves clogged. Supposedly you can clean them out but I just removed them and never had any further issue.

You really should make an effort to go, plus we’ll get to meet in person! This year it seems they have 2 track days planned and I’m super stocked.

I haven’t looked into that, but I should now that you mention it. The NBs have a few more EVAP components than the NAs. Specifically an ECU controlled solenoid (CDCV) that closes a filtered (intake?) vent, and a pressure valve also ECU controlled.

Do you happen to know how it all interacts in an NB? I was able to find a diagram in the service manual, but no detailed explanation of each components function. From my reading, it seems the CDCV is just to check for EVAP leaks by pulling a vacuum on the tank. The Link is able to drive the CDCV and purge valve, so I did a bit of experimentation that I’ll detail in the next post.

Honestly I think I’m better off ripping it all out and venting it like an old car as Curly suggested in a different forum. Link to that post: https://forums.linkecu.com/topic/182...ifferent-baps/

Just checked the FM Summer camp dates this year. Was hoping it was in early July as a buddy and I are currently talking about going out to PPIR for the GTA race there on July 4-6. Would have been cool to race there then catch a day with FM on the way back, though maybe a bit ambitious as far as the timeframe goes haha. I'll let you know if anything changes and I end up making it out! Would be great to match a face to the name and it's been too long since I visited CO in the Summer!

Ahh, yes, I didn't even consider your NB is an OBDII car. Yes - I haven't dealt with an NB evap system firsthand before, but all OBDII equipped cars have a monitoring system to check for leaks in the fuel tank/vent system. Your car should have a solenoid that opens and closes the vapor vent on your car's charcoal canister, as well as the purge valve that's PWM'd by the ECU to suck fuel vapors into the intake manfold. Then there's a fuel tank pressure sensor as well. Again, I haven't ever looked at an NB evap system firsthand but this is standard for all CA smog legal OBDII vehicles (which most vehicles are), as it eliminates the need to pressure test the system with a separate machine during a smog test.

When the car is shut off after a drive cycle, the ECU closes the canister vent and monitors the amount of time it takes for the fuel tank pressure to bleed back up to atmospheric pressure. If it bleeds up too quickly, the ECU will set a code and check engine light depending on the inferred size of the leak. None of this matters if you have a standalone, obviously. None of the ECUs I know of have controls for the canister vent or purge solenoids unless an additional output is installed by the user to control them. What Curly suggested in that forum would be worthwhile on your car, none of the evap emissions stuff is doing anything since the standalone ECU's been installed. I pulled the evap canister on my car as well and now have nothing but a line attached to my front subframe venting to the atmosphere.

Apologies for diving in on the topic. I deal with this stuff at work a bunch and love regurgitating the information lol.

FWIW I've had an issue filling up my NB for the past couple years. I have to trickle the gas in super slowly. It's on my list of things to fix.
This happens even when it's freezing outside and I've just warmed the car up enough to drive down ~1 mile to the gas station. I'm guessing one of my valves is clogged.

I was looking into the CDCV recently but didn't find much info on it. Once it warms up and I get the hard top off I plan to get back there and see if I can fix it.

The canister vent valve may be sticking shut or the check valve may be clogged. IIRC now, the NB actually has two vapor canisters, one under the vehicle near the RR wheel well and one in the engine bay. If you disconnect the inlet line to the canister near the RR wheel well and your refueling issue goes away, it's the canister vent that's plugged. If you disconnect the line and still have issues refueling, it's more likely the check valve. Also possible but low probability is a pinched or collapsed line, but I'd put my money on the check valve first, then the canister.

Thanks for all the info. This is aligns with what I had gathered and taken educated guesses on, so I'm glad for that. In my case it seems the main issue was an exhaust leak at the 2-bolt muffler flange that points straight at the fuel tank. Fixing that removed the majority of the pressurization, but not all. I'll take a look at those valves this weekend, and also check if the exhaust leak returned.

A really cool aspect of the Link ECU is that it can control emission devices, and the plugin ECU is already wired to these solenoids. There is a caveat in the NB1 ECU where the purge valve is pinned to a On/Off Aux output instead of a PWM output, but I made a math channel that flips it On/Off to do a pseudo-PWM. I'll show all that in the next post!

@SimBa, I haven't had any issues refueling, but follow Z_WAAAAAZ's advice and you're likely to find the issues in one of those! Let us know what you find.

Man, time flies. I'll condense the rest of the season in this post to get the thread up to date and share what's been happening lately!

After the FM 2023 happenings with the fuel tank getting pressurized I wanted to experiment with the purge valve. Curly pointed out that the Link ECU has connections to the NB fuel tank pressure sensor and that the likely cause was an exhaust leak at the 2 bolt flange right below the tank.

I went looking through the forum and the service manual for any information about how Purge control is done and for information on the sensor calibrations. I found sensor calibration in the Mazda service manual and configured it all in the ECU.

https://i.imgur.com/8aMvysE.png

https://i.imgur.com/qCEOj8U.png

https://i.imgur.com/UbSCBRA.png

The hardware setup consisted of the OEM purge overflow tank and valve plumbed to the vacuum manifold shared by the ITBs for a source of vacuum. The Link ECU uses the OEM purge wiring in an On/Off output instead of PWM, but KORacing suggested that I could use a Math channel to mimic a PWM output. A beer with a friend later and we decided to try a sine function with a counter.

https://i.imgur.com/j2A1k83.png

The idea is to wait for the car to be in "cruise state" for half a second, then actuate the purge valve in pseudo-PWM using Math block 6. Once the purge is active, the ECU removes a bit of fuel per the 4D fuel table. And this setup worked! I didn't expect it to cause the car to go so flipping rich (10-20%) depending on load, but that explains why OEMs do PWM to control the richness on MAF setups? I played with doing On/Off control as well, and kept the 4D fuel correction to account for the rich condition. I used this setup in the car for months with decent success. The only issue was that the VE table was really broken at the low TPS mid-high RPM areas as a result of bad injector data, which made the corrections inaccurate in those spots. At the end of the day, the cause and permanent fix of the pressurization was to eliminate the exhaust leak that Curly mentioned.

ABQ Super Lap Round 4

Up next was ABQ Super Lap Round 4 and some suspension and alignment changes. I wanted to try more front negative camber and less caster. Purchased a set of ELBJs from FM and got to wrenching a few days before the trackday. Found out one of the parts was defective and wouldn't bolt on :eek3:. FM Support sent a replacement and I was able to get the car aligned the day before the event!

https://i.imgur.com/3B6OC0q.jpg
Hard to tell, but the hole is not centered enough to fit

https://i.imgur.com/m12Xjkj.jpg
Alignment I went with

Below is the time attack session from that day. The car did well, but it was different than what I was used to. Mainly, it was easier to oversteer and kept locking the front wheels under braking. It took a while to get used to the new dynamics. I had played with the rear damper stiffness which made the oversteer worse. It was also a warm day and the Accelera tires were at the end of their life.



At the end of the day, my 1:38.xx times were good enough for my first podium! Usually I end up in 4th, but the 3rd place didn't participate that day.

https://i.imgur.com/QTxFMiC.jpg

While I was in the mood to experiment, I enabled flat-shifting in the G4X (called gear shift control in the software). With a combination of ignition retard and fuel cut I got it to work smoothly with no bangs. This setup also uses a gear/speed calculation to match the RPMs of the next gear to make the exit of the cuts smooth as well. That function is more useful for sequential type boxes, but doesn't hurt in an H pattern. It's an odd feeling keeping your foot planted while shifting...



I don't use the GSC or launch control often, but it's a fun party trick and I intend to use it in the 2024 season.

I spent the next months working on other things (Stealth, house, family, business) and Scooter didn't get much love. But then ABQ Super Lap Round 7 was coming up. I changed the alignment once again, got new tires (Kumho ECSTA VQ730s), and brought friends along!

https://i.imgur.com/e06Cp8V.jpg
Accelera tires were done after a few trackdays, a couple thousand road miles, and more camber

https://i.imgur.com/nWMvmbH.jpg
New alignment. Less front camber, more caster

https://i.imgur.com/sE2l1lQ.jpg

https://i.imgur.com/mr59uwN.jpg
It was Balloon Fiesta weekend!

https://i.imgur.com/LNLWCoY.jpg

https://i.imgur.com/Z9o1u1i.jpg

https://i.imgur.com/Wcoy0fl.jpg

https://i.imgur.com/Nhy0Bql.jpg

https://i.imgur.com/Le3jnUd.jpg

https://i.imgur.com/CDFGZBF.jpg

https://i.imgur.com/OnIbbtU.jpg

https://i.imgur.com/HxDTo3M.jpg







We ended in 4th again, but with a much better PB of 1:36.605! That's roughly spec Miata mid/rear in this track. Scooter did great, and the Kumho tires are awesome. This was one of my favorite days on track so far and I was happy with the new alignment.

ABQ Super Lap Round 8

Next was Super Lap Round 8 and there were no changes from the previous round. This time I wanted to focus on improving confidence and being more consistent. One aspect I was trying to focus on was not closing the throttle abruptly (or at all) in some corners. I added telemetry to the videos for easier analysis too ;)

First practice we did 1:36.770 and 1:37.010. Not bad.

Second practice (with @Fireindc as passenger!), 1:36.714, 1:37.042, 1:36.949.

In time attack I was hitting the limiter between corner 2 and 3, so went to 4th gear instead of staying in 3rd, and got a bit braver in corner 13 and 14. The times were 1:35.895, 1:35.684, 1:35.531 !!!! WOOOOOT !!!!. I was ecstatic. Video or it didn't happen.



This new PB put us in 4th place again, but the competition was very close (0.2 or 0.3s apart) between 2nd, 3rd and 4th. RX8, Integra GSR, Scooter respectively. First place is strongly taken by our friend Brian and his NC3.

https://i.imgur.com/LVBoRt7.jpg

This concluded the events for 2023. Scooter felt dialed in the suspension, brakes and alignment department. I realized that I only let the car "dance" in 2 or 3 corners, so I need to work on trusting the grip more. I have things to try in 2024, but I was (and am) very proud and happy with 2023.

Winter was a busy time with family, so I didn't look at the car for a month or two. The break was much needed.

https://i.imgur.com/8Oy9DF2.jpg

https://i.imgur.com/0lCQrKS.jpg

https://i.imgur.com/zgqURvq.jpg

But with spring 2024 fast approaching, it was time to start prepping...

https://i.imgur.com/1PKgljm.jpg
Sneak peek ;)

Good work on the evap stuff! You're making me realize I still need to dig into that on my car.

Congrats on the podium as well! Seems like it should be the first of many.

Loving the updates bud! Didn't realize that 1:35 you ran last event was after a pass on the straight, nice job setting it up for t1 after that! Also love those clips of you throwing scooter into t1, really gives a good feeling for the speed you feel hucking into that corner.

Seing as how Ricardo re-tuned most of my map (everything but the timing map), he's my go to guy for tuning now days. We have fun.

https://cimg2.ibsrv.net/gimg/www.mia...3fd55b70c5.jpg
https://cimg4.ibsrv.net/gimg/www.mia...dd1d6c0b00.jpg

Ricardo thinking "just a few more KPA" with his evil grin as he smashes the page up botton:

https://cimg7.ibsrv.net/gimg/www.mia...19c5bf4ccc.jpg

Shucks, I just saw your post from 3/8! Great job outlining the parameters and fix on your issue. I forgot you had a Link and had no idea they had provisions for the factory emissions stuff.

Congrats on the podium and continuous improvements on your times as well. Great pics and videos as well. Doesn't matter if the usual third place member didn't show up, I'd tell all my buddies it was a podium finish still :rofl:

Thanks! I hope I can get a couple more podiums this year.

The purge control was one of my classic overthinking projects, but fun to figure out. I don't know if you've one of the Mazda service manuals downloaded but the diagram I posted above has all the various parts of the NB EVAP that you may need to check on yours.

Thanks, Nate! Malcom was having a misfire and luckily let me by with no major loss of time. The little slide into T11 was very costly. I'm glad you enjoyed those clips. They're some of my favorites and get me really stoked to drive again.

Big thanks for the shoutout! Glad you're happy with my work; It has been a lot of fun.

Haha I hadn't noticed my face in that picture, but I do remember that day fondly. Flex fuel high boost Miata was a new world for me and made me realize how much I miss boost :cry:. Soon.....

No worries dude. Life gets busy and you have been crushing it with non-stop projects! Doing my best to share info and hope someone finds it useful or at least interesting.

Thanks. I've been fortunate that my friends took pictures and videos while spectating. It adds a new level to trackdays having people helping and hanging around. I definitely bragged to a few friends about the podium :rofl:. Scooter already has rotary syndrome (burning a quart of oil every 100-200 miles now), so maybe it'll gain some HP from that RX8? :x:

I'm excited to soon share what's been happening in the past few weeks. ABQ Super Lap Round 1 is this weekend. Let's see how it goes!

Lead Up to 2024 ABQ Super Lap Round 1

This past Saturday was the first round of ABQ Super Lap. I wish I had recorded more and taken pictures but as you will see, I had no time.

Let's start with the leadup to the weekend:

A couple of months ago I was able to purchase a towing vehicular. 2007 Tundra SR5 with towing package. With 136k miles, it needed some TLC but seemed like a good start. I've never towed a car before, so learning experience. This is also my first truck and V8...fun.

https://i.imgur.com/i38u2mC.jpg
https://i.imgur.com/gizM2aA.jpg

No pics of the TLC done, but spark plugs, serpentine belt, some hoses here and there, an attempted alignment (camber bolts need replacing) and the Tundra was good to go. Oil was still fresh so left it be.

On the Miata side, it was time to tackle the IATs. On a cool day in early Spring, IATs in Scooter would get upwards of 40C (104F) on the street, and even more on track. They never come down while I drive. Actually, even in winter they'll get to the 40s with enough driving. Crazy. Enter the Reverie carbon airbox!

https://i.imgur.com/QR098yd.jpg

I've wanted this airbox for ever. Hard to swallow the price, but it is a beautiful piece. The filter above goes within the airbox. I like the idea of no filter on the piping for a cleaner install.

A few issues came up while test fitting:
1. Fuel line in the way
2. New air filter isn't tall enough to clear the 60mm trumpets
3. Unable to install with strut bar mount in place
4. Once installed, clearance to strut bar was tight

Fixing the fuel line was easy. Loosen the AN fitting and use a longer hose. I broke one of the quick disconnect inserts but they're available at the local store.

Switched to the 35mm Borla trumpets to fit the filter. A bit bummed about that, but I'll likely print a set of 45 or 50mm trumpets later.

I tried trimming and cutting the mount some but at the end just had to delete the strut bar all together. Not a huge difference in driving dynamics with it gone, but turn in response isn't the same.

https://i.imgur.com/BbSnrH2.jpg

https://i.imgur.com/MCeS67J.jpg

https://i.imgur.com/9IMrPFF.jpg

Installing it was annoying because of this bottom holder. I was planning to cut it, but was recommended to space it out instead, which worked really well. Had to use longer bolts here.

https://i.imgur.com/vdZiIWM.jpg

https://i.imgur.com/lgPRXEK.jpg

And the last bit was routing some intake piping somewhere colder than the engine bay. Feeling a bit tired and out of time, I just put it behind the headlight for now. This spot seemed to be about 10C hotter than ambient after driving around. Eventually I would like to have it somewhere with a ram effect, or at least straight to ambient air.

https://i.imgur.com/zzcwGcn.jpg

https://i.imgur.com/IwHN1KB.jpg

https://i.imgur.com/KMIcEch.jpg

It was time to add a bit of flair to Scooter, and these APR mirrors got to my door. They are from R Theory because of the ready made adapters. Pretty easy install overall.

https://i.imgur.com/hPbobcT.jpg

https://i.imgur.com/Gy6Rjc8.jpg

For a while I had been using tie-wraps to hold the Dual external GPS I use for laptiming. Figured it was time for an upgrade and designed and printed this holder for it. It has an adapter to fit the GoPro mounts I made for the rollbar :D, but I also made it compatible with RAM mount adapters.

https://i.imgur.com/vEtlqYI.jpg

https://i.imgur.com/ae0UBh7.jpg

https://i.imgur.com/kPjA0cq.jpg

Now for the actual track prep! Scooter was in dire need of an oil change (somehow it keeps getting diluted within a few hundred miles), a brake bleed and it was also time to grease the bronze bearings in the suspension. It was Thursday, trackday was Saturday. Plenty of time.

While greasing the suspension, I see this:

https://i.imgur.com/Lj3WjFZ.jpg
https://i.imgur.com/uWfTC3l.jpg
:ohnoes:

Well hell. Alignment added to the TODO. The local mechanic squeezed me in on Friday and I quickly marked the camber bolts after.

https://i.imgur.com/t3cG1QV.jpg

The alignment had moved some (little numbers above the new ones), but it surprisingly wasn't as bad as it could have been. At this point the car was ready to rock.

I wanted to learn how to trailer the car so I can start traveling to other tracks. I don't have a place to store a trailer at the moment, so I picked up a U-Hawl. It's a bit annoying (and costly on fuel/time) having to drive off town to get the trailer, but it'll do for now. Didn't take pics, but had the car loaded Friday night and all the gear together.

ABQ Super Lap Round 1

Woke up early and started the drive to the track 2 hours away. Took it slow, going around 60-65mph on the interstate and everything went great. As I'm pulling into the pits it dawned on me that I forgot something...

https://i.imgur.com/PKTK5nj.jpg
Keys were at home. :noob: :facepalm: :violin: :crx:

For fucks sake.

Fiancée pulled an MVP move and met me half way in Santa Fe, and I got back to the track as the last group was lapping before lunch. The organizers let me do my practice sessions during lunch while everyone else watched my stupid ass be stupid. You see, I also wanted to play with Gear Shift Control. In the second practice session I was out banging gears and stuff was working well...until I lost track of what gear I was in...and instead of slowing down and regrouping I stayed in it...brapapapaap. I have no idea what I did, but 404, gear not found. With that fiasco I aborted the session and pulled into the pits to calm down because I was over my head. Haven't looked at the datalogs yet, but the Max Engine Speed in the ECU only shows 7406RPM, so I didn't overrev at least.

The car felt well, however. Suspension was doing its job, and alignment felt good too. It was extremely windy and a bit cold, and the tires took longer than usual to come alive. I was struggling keeping oil temp high enough for full RPM duty (limiter works with oil temp in Scooter). It took about a warmup and a hotlap to come up to temp. But I made due, and ended up doing a 1:37.236 which put us in 5th. Far from last year's PB, but between the set backs, being exhausted and rushed, that's really the best I could muster. For perspective, I drove 250 miles that morning before my laps started, between going to the track, round trip to get the keys, then rushing to get the car ready for time attack (I couldn't unload it because I had locked the doors!). That added up. Total truck milage for the day was 360 after the return trip home. I could barely function Saturday night.

https://i.imgur.com/bfFMdNI.jpg
Thanks to @Fireindc for the only track pic of the day :bigtu:

https://i.imgur.com/wHh1qhq.jpg
Almost forgot to take pics of Scooter on the trailer. Taken at the entrance of town

It wasn't all doom and gloom though. A lot of things went well and I have a better idea of what sort of trailer I want, and with what features. The Tundra did fantastic, and towing went without a hitch. The external GPS rollbar mount worked a treat, and it's always great to hangout with cool peeps. Last but not least, the airbox did it's job keeping the IATs lower. Temps climbed to 42C (107F) while staging (idling 10+ minutes), and dropped to 30-32C (86F) while driving. It may have been better if I didn't have to let the engine idle for so long to keep the oil temp up. I'll eventually build a box around the headlight to keep temps lower still, and maybe use gold foil in strategic places. The car is much quieter with the airbox, but I can swap to the filter at will for loud ITB noises :D

Needless to say, I'm not proud of how things went at the track, and mainly feel I let Scooter down. Next Super Lap is May 19th and I'm not sure if I'll make it; Redemption is needed. Might have to sign up for an SCCA or SWMS HPDE event. "Keys" are now bold, ALL CAPS and highlighted red in the track prep checklist.