Turbocharge all the things.

Nobody's going to come up to you at the gas station or the racetrack admiring your car and say, "How much sense does that make? They're going to say, "How much power does that make?"

 

 

There's the voices I initially expected to hear. Appreciate you guys haha.

More tune adjustments and general d*cking around this weekend. After messing with fueling on my homemade tune, I was convinced that the car wasn't running out of fuel pump at the top end. I was WRONG.

Last week, I didn't feel there was much of a need to swap in the beefier DW300 fuel pump yet, but I wanted to play with the car so I decided to install it. I pulled the fuel pump assembly on Weds or Thurs and disassembled the hanger to get to the pump itself. Pretty straightforward but I'll admit it took me embarassingly long to find the clip to disconnect the sender from the rest of the assembly.



Sending unit with the fresh DW300. Don't worry, I pulled the little sucker out of the wrapper before installing it.



The original fuel filter was packed with debris so I'm glad I got that replaced as well. There's no inline fuel filter on the NC so this little guy is the only thing between the tank and injectors. The DW300 didn't come with a filter but I had ordered one for $10 off of eBay just in case.

All back together and good to go! Or so I thought...

When I replaced the pump last week, I had about 5/8 of a tank left in the car. Friday, the tank hit 1/2 and the car started fuel starving hard. Fuel trims pegged rich and the thing was stumbling all over the place. I limped it to the gas station (still suspecting the issue was dirt in the MAF sensor at this point) and filled it back up as I was planning on driving Saturday morning. As soon as the car got a bit of ethanol in it, the issue stopped. Drove it home no problem and pulled the fuel pump out to find that I completely forgot to install the plastic spacer on the fuel pump nipple that keeps the o-rings from sliding down. The OEM pump and spacer were at my work and the garage was closed at this point, so I got to go back to work on Saturday and do the job again.



O-rings as they were situated when I pulled the pump out.



O-rings perched atop the spacer just as god intended.

Got everything back together and drove the car around a bit to do some datalogging and see if any retuning was needed for the fuel map. A few months ago, I bought the ECUtek bluetooth dongle so that I could interface with my phone and switch tunes on the fly if I needed to go from e85 to 91 or vice versa. Since we never finished dialing in the 91 octane tune, I haven't got almost any use out of it, and was mildly remorseful for the purchase. Well that's changed and I'm definitely getting my money's worth out of the thing now. Being able to whip out my phone and take some datalogs and email them to myself on the way to work has been awesome. I took some logs at high load and WOT on the way home and chuckled to myself. WOT AFR's were now low-11's across the board and the ECU was pulling fuel at higher loads in closed loop as well. Luckily the idle and cruise cells were unaffected. Good thing because I've been dialing that part of the fuel map in and have most of the fuel trims between 0-3% max in those regions. I made some adjustments to the fuel map yesterday morning then met up with some buddies for a mountain run to enjoy the fruits of my labor. The car ran great. AFR's in the low-mid 12's across the board at WOT. I'll subtract a tiny bit of fuel from some of the cells this week but it's driving great and is still just so much damn fun.


You vs the guy she tells you not to worry about.



I was up in the mountains until almost 9pm last night, which is hella late for me. Longer days are nice.

More debauchery this week maybe. I've got a wedding this weekend and some buddies and I are heading up to Oregon next weekend for a mountain bike trip so I'm gonna have to get my fix in.

 

Hell yeah, interesting to see what tuning looks like on the NC. I loved being able to connect to my Speeduino via bluetooth. Datalogging, checking sensor values, or making a quick change like launch control RPM was so convenient.

I have to wonder if Kraken will raise those NC turbo kit prices once more have sold. Considering it's a newer product I could see him selling them a bit cheaper to encourage people to try them out.

Any reason to go DW300 over a 200? I'm guess there isn't much downside going bigger there aside from maybe some extra noise?

 

Yeah dude, tuning this thing is a new venture but I'm loving it. So satisfying starting to tweak with the ECU after reading up and being too scared to touch it for months lol. The Link doesn't have any sort of bluetooth connectivity? Or is bluetooth something that requires an additional expansion of sorts? I'd have imagined that was an option given how sophisticated the ECU is.

The Kraken kit was on "sale pricing" until Tuesday this week. I think he said he was offering a big discount on the intercooler and one or two other things until then. Just checked and a complete kit with a full exhaust is about $500 more now. Still pretty low price all things considered at around $3,500...

I think the DW200 flows just a little bit more than the stock NC fuel pump. There's guys running the stock pump up to about 240whp on pump gas, and so I haven't seen anybody selling pumps for the NC under a 340LPH rating. I figured the same thing as with the injectors, go overkill just in case. The pump is loudish when priming but not so loud you can hear it while driving. I like it haha

 

No massive developments in the last couple weeks, but I've definitely still been messing with the car!

So a couple weeks ago, I remembered I had some Summit Racing bucks to spend. After some careful deliberation, I decided against being reasonable and buying a bunch of consumables/maintenance items, and instead ordered an upsized Bosch 68mm throttle body. The stock NC throttle body has a 60mm inner bore, and really isn't a big restriction in the system. However, the N/A guys report a 3-5whp increase on the 2.5 by swapping to the bigger Bosch unit. A couple users have done before and after tests for throttle body-based restriction by comparing MAP readings before and after. The TB swap appears to free up a couple KPA closer to redline. My MAP readings at full throttle stay at ~99KPA up until 5k rpm, where they slowly decrease to around 94KPA at redline.

So, anyways, I figured I'd toss one on. It's definitely not the cheapest ~4whp ever, with the unit retailing at $156 on Summit, but luckily my Summit Bucks covered most of it. Really, I just wanted to tinker with the car some more and figured this would be a fun project. As an added bonus, the Bosch TB uses a different electrical connector, so I'd get to have some fun doing a little bit of rewiring as well.

I didn't take any photos of the TB aside from this silly one. The TB on the right isn't off of the Miata, it's off a 1.0L Ford EcoSport. Tiny little guy.



But there was a hiccup with my plans. As a weird coincidence, people on the NC Facebook groups started complaining en masse about the Bosch TB's (and their knockoff counterparts) failing left and right the week I got mine. Super weird, as this has been a common upgrade for a few years now and I'd never heard a peep about failures. My buddy Frankie has one of these Bosch units on his car, and got spooked by the posts. He's had his throttle body for 3-4 months and hasn't had any issues, but he was running the MTTC in Laguna Seca seven hours away and didn't want to chance a failure. He messaged me and ended up grabbing my Bosch TB as a spare in case his failed.

And good thing he did. Halfway through the day on Saturday his throttle body died mid-session, leaving him on the side of the track. He bolted mine on and ended up buying it off me outright. So now I was back at square one. If anything, I was glad I could help him out haha.

So, in the interest of keeping myself busy, I decided to play around and find another "small" modification. Enter the MazdaSpeed 3 MAF sensor swap.


I also don't have a spectacular photo to associate with this one. The MS3 MAF is visually indistinguishable from the stock one. Bolts up in the MAF housing just like the original and uses the same electrical connector.

The stock NC MAF can meter up to ~275-300whp of airflow when mounted in a 2.5" housing before it's maxed out and just can't read any higher, regardless of what you input for scaling settings. You can get around this limitation by running a speed density-based tune... which requires purchasing the $1,800 Pro tuning suite if you're self-tuning on ECUtek. The workaround for MAF users is that the MazdaSpeed 3 MAF sensor can be used as a drop-in replacement for the stock sensor, and can meter much more airflow before maxxing out. Now, you can also just bump up to a 3" MAF tube and rescale the MAF tables in your tune, but where's the fun in that? I don't need the additional metering potential of a larger MAF at this point, but I don't want to be maxed out and have the car run lean at peak power if/when this thing gets a built engine or boost. So I grabbed a Speed 3 MAF and got to tweaking.

The Speed 3 MAF sensor has a much higher metering potential, and obviously requires tweaks to the MAF tables because of that. Luckily, it's a common upgrade for high HP NC guys at this point, and has a lot of documentation because of that. Those of you who are really into the nitty gritty stuff will probably appreciate this article from M.net from a user who used a voltmeter and various air-moving apparatuses to measure the voltage scaling between the stock NC MAF along with the Speed 3 unit. 3.5" MAF Scaling - MX-5 Miata Forum

Luckily, some of the community members have taken the data and dumbed it down for simpler folk like myself. If you want to use the Speed 3 MAF in your car, take both of your MAF tables and multiply them by 1.38. Then modify your scaling if needed based on your fuel trim readings.



So that's what I did. There's my previous MAF table on the left, and the new table on the right. Both tables ended up looking like the one on the right. And the simple multiplication factor worked! I swapped in the new sensor and the car started right up! Fuel trims at idle were still nearly zero, and after driving it and reviewing a couple datalogs, not much tweaking was needed. The ECU was pulling up to 10% fuel during certain cruising conditions and I also had to tweak my fuel scaling at full throttle a bit, but that was about it. I've done a couple tune revisions in the past week and am pretty close to getting it fully dialed. WOT fueling is within spec, just working on getting those fuel trims closer to zero at cruise. I've still been tuning fueling using the load scaling table only, and haven't messed with the MAF scaling table. This approach seems to be producing the desired results still. I'll post a screenshot of the finished load scaling map once I'm done with it.



Mandatory weekend drive photo. Got home from our Oakridge, Oregon trip yesterday and had this morning free. Had to get a drive in before the weekend's over. Got the car up on jack stands in the garage tonight. I decided to sign up for the last NASA AZ race before Summer this weekend. Gonna be heading out to Phoenix Friday night to compete and instruct Saturday morning. Gates and tech are going to start at 4:45AM, the track's short, and it's going to be hot as hell, but I'm excited nonetheless. TT5 class has 5 competitors, one of which is a GR86 driver named Tyler, who I went back and forth with for the 1st place at the NASA Chuckwalla event back in February. At any rate, it should be a party! (Aside from the heat).

Random bonus pics from OR. No car-related stuff but an absolutely killer weekend with the guys.

 

Which transition bike is that? How do you like it? Off topic buy my old broken *** is looking for a modern 29er full squish so curious what you'd recommend now days.

 

Hey, another thing I can dork out about! You're still rocking the hardtail-only program, right? I'm sure that's not conducive to the whole back injury situation...

It's a Sentinel V2, Transition's 160/150mm 29er. I absolutely love the thing. I bought it at the tail end of 2021 and still haven't found enough fault to swap it out for something newer. It's a mid-travel bike but the geometry is really aggressive which allows it to punch a bit above it's weight, or what the travel numbers would suggest. Really good option if you're looking to hit burly trails at the bike park, but don't want so much bike that you dread pedaling it on the mellower stuff. I guess my only gripe with it would be that I managed to crack it at a weld in the seat tube a couple months back. But that was after god knows how many miles of abuse. Transition was super easy to work with though and shipped out a replacement triangle the day after I contacted them.

Take what I say with a grain of salt 'cause I've been less in the loop since I stopped working at a bike shop in 2019, but there seem to be more good options out there these days than bad. At some point, most bike brands started settling on similar geometries and suspension designs that seemed to work best. In no particular order, a handful of full squish 29ers that seem to be doing favorably right now are the new Specialized Stumpjumper, Ibis Ripmo, Santa Cruz Hightower. I'd also consider getting a Commencal, as they're super reasonably priced and those guys make a really mean bike. I've been eyeing their short travel T.E.M.P.O. to replace my "XC" rig, a 120mm Fuji Rakan.

Message me if you start digging deeper into it. I can type tons about this stuff haha

 

Thanks! I'm outta the loop too, since I stopped working at a bike shop in 2017. I've been happy with my plus hardtail with 140mm travel for the most part, happily riding anything my friends on full sussers do and able to hang. Always liked how a HT rode like a big bmx bike, but bikes these days look really awesome. I've been riding my ht on tame trails lately again and feeling good, but really eyeing a trail susser to keep impact low. And who doesn't like a good excuse for a new bike. Bike needs to be able to pedal efficiently and decend equally, maybe a bike park here or there but definitely not the focus. I think even most "enduro" (back in my day we used to call these "all mountain") bikes are gonna be way too sluggish on my average ride, if I'm being honest with myself, I got out of FS bikes because they weren't poppy and responsive enough circa 2012-2015 and made the average ride boring, imo.

Im looking at something firmly in the "trailbike" category now, with 140/150 travel and 29" wheels. Just like you said, almost every single bike ive looked at has similar geo with that 65* HTA and 435mm CS I like a short rear end for back wheel stuff and always liked slacker bikes, so all the new stuff looks pretty awesome.

I was eyeing more budget stuff like the kona process 153, polygon suskiu t8, marin rift zone etc. Just because I'm blown away that you can get a capable "real" FS in the 2k range. Crazy. The commencal meta tr really has my eye now so thanks for the suggestions.

Leaning towards new but budget kit and can upgrade as needed, but could be open to a lightly used setup. Used is weird with mtb for me because some people thrash the living **** outta their kit while others barely ride them.

 

Haha oh you got the party hardtail! Ok yeah, coming off that you're going to feel like Superman even on a 120-140mm travel frame. I see where you're coming from.

I also see where you're coming from regarding the budget stuff. I threw out the Specialized, Santa Cruz, etc as examples but yeah prices on some brands have gotten crazy cheap since the bike industry imploded post-Covid! I've had my eye on a new bike just because I feel like I should buy one while they're still 50% off.

I've had my eye on some variation of the GT Sensor to replace my short travel bike as well. Maybe these will be of interest to you. GT just went under (unfortunately), but Cannondale took over their warranty program so you can still get replacements/frame parts if needed. The discounts available are DEEP.

I'll PM you if I catch any other 140-150mm bikes that hit my radar. Gotta stop myself from jacking my own thread lol.

https://www.jensonusa.com/gt-sensor-st-carbon-pro-bike
https://www.jensonusa.com/gt-sensor-carbon-elite-bike

 

Headed out and ready to race in Phoenix tomorrow. Had a busy week but managed to finish prepping the car last night. Swapped my DTC60 pads back in, removed all the non-TT5-legal aero bits, changed the oil and swapped out all four tires. I’m in a weird spot where I have a full set of nuked RC1’s, three more with two track days on them (I flatted the fourth due to that valve stem failure), and three new ones. I tossed on three of the two-trackday tires and put one freshie on the rear right as we’re running clockwise tomorrow and I want to keep it semi-new for Buttonwillow in a few weeks.



At the NASA event back in March, I got bumped up a class for my fender vents/cuts. Since I couldn’t find an unmolested pair of fenders in time for this weekend. I messaged the TT director in advance regarding the situation, and was told they didn’t care about the fender cuts so long as I plugged the vents. I couldn’t find the plugs I’d previously made, so I cut up an ABS sheet I had laying around and zip tied it to the vents for a super clean OEM look.



My backup 2.5 also showed up yesterday. The $366 one I posted about a few weeks ago fell through, seller told me they didn’t actually have it and sent a refund. Weird. I ended up finding this one out of a 2017 Ford Escape that was rear-ended. Paid $488 all-in, but this one has 64k miles instead of 111k like the other motor, so maybe that’s good for something. I don’t really think it matters, they’re econobox motors. Probably more important that the oil changes were done at the correct intervals. I haven’t got very deep into it yet. Borescoped the cylinders yesterday, the pistons have a bit of carbon buildup but the cylinder walls look good. I dripped some ATF into each cylinder and let it sit overnight then rotated the motor over by hand today. It spun freely right from the get go so we’re off to a good start. I’ll pull the VC and oil pan next week and continue checking it over. Hopefully I won’t have to spend next weekend tossing it in the car



Tomorrow should be action-packed. Gates and registration open at 4:15am, driver’s meeting is at 5:30, and we’re on track for the practice session at 5:50. There’s three competition sessions, the last of which ends at 11:15. I’ll be instructing a first-timer as well. And it’s going to be 95*+ by 11:00. I foresee myself at the casino across the road at noon mowing down a basket of chicken strips and a Shirley temple lol.



Firebird East is a short track, but I think that should work to my advantage as there’s less to learn. Hopefully the car can snag a decent result tomorrow!

 

Any plans to go to the Utah event at the beginning of August? I just signed up for the 6 hour enduro there, trying to decide how much of the sprint ST4 weekend I want to run in addition to that.

UMC is a very cool track if you've never been, and the enduro is a ton of fun.

--Ian

 

Hmmm, I could potentially be talked into that. I wanted to go last year for NASA National champs but my motor called it quits due to timing belt failure two weeks before.. The track looks like a good time and I’ve got a buddy out there that I keep telling I’ll link up for some laps with eventually haha.

Only caveat is that my Fiancé’s birthday is on the 7th and our anniversary is two days prior so I gotta make sure we’re not planning to celebrate the weekend of the race. I’ll stay in touch.

 

I'll take it!



It was an exhausting weekend, I threw away the win with a silly mistake, and the weather was hot as heck, but the suicide mission to AZ was a success!

I knew from the get go that I was going to be running on minimal sleep this weekend. NASA AZ set this event up as a morning-only, to avoid the afternoon heat. Gates opened at 4am, driver's meeting was at 5:30, and we were on track for the first session at 5:50. I left work in Orange County at 4:30pm... The non-turbo Ford Transit isn't exactly peppy to begin with, but it does not like to cruise fast on the freeway with the trailer attached. I averaged ~60mph all the way out to Phoenix, and got to the track just after midnight. Right as I pulled off the freeway, a hundred yards from the track entrance, one of the trailer tires blew out. I'm going to say that was super lucky, as there probably wasn't much in the way of roadside assistance in the middle of the desert on the drive out. I limped my rigs into the parking lot and passed out... or tried to. The problem with van-lifing in hot areas is that your vehicle radiates heat for a while after you turn it off, even more so if you just drove it for 7+ hours straight. Running the engine with the AC on just prolongs the heat soak, so you're hosed either way. I put my roof vent fan on full blast and finally the thing cooled off enough to knock out around 1 or 1:30. I got some beauty sleep and woke up at 4 to start getting ready.

Luckily, that was the lowest point of the trip. Some caffeine and a microwaved burrito later and I was feeling temporarily well enough to go set some times. I linked up with my new buddy Tyler (the one I was going back and forth with for the TT5 win at Chuckwalla in Feb) as well as my student for the day, another GR86 driver. It was mine and Tyler's first time driving this track so we were on equal footing. We got through the 10-minute practice session at 5:50 and were back on track for the first competition session at 6:30. Things got exciting real fast.

Side note, ignore the giant orange shirt. NASA AZ has their instructors wear orange T-shirts. I don't own an orange T-shirt so I had to borrow one lol.

First session out, I wasn't absolutely dialed in yet, but I threw down a handful of consistent laps. My best was a 1:03.97 (which would end up being my PB for the day) followed by a handful of 1:04's. I was feeling pretty good, then I got a little gung-ho and pushed the braking zone into T1 a little too hard...


Which rendered my time for the session null. And that was a bummer because checking the leaderboard after showed this gap between Tyler and I



If that's not a tight race then I don't know what is! Our next session was at 8:30, and it was going to be a decent bit warmer, but I hoped I'd have the track a little more dialed in and be able to drive the car to another 1:03. Unfortunately, that didn't happen. I drove the track much better, dialing in braking zones and using up all of the available curbings, but the higher ambient temps took some of the wind out of my sails. I finished session 2 with a 1:04.32 and session 3 with a 1:04.77. Close but not close enough! Tyler ended up taking the W, with just 0.32 separating the two of us. Still a proper tight race!



While this was all happening Uhaul sent someone out to change my blown trailer tire. The issue didn't take a single second out of my Saturday, lucky break!



After the race, I was going to try to bag a quick mountain bike ride, as there's a spot I'm familiar with only a few miles from the track. My eyes were bigger than my stomach for that mission, though. Despite eating and drinking water all morning, I was still hot, hungry, sleep-deprived, and thirsty as heck. I grabbed a bite to eat, jumped in a nearby pool, and started the drive home at 3 or so. Made it a couple hours from home, started getting tired, remembered that story about Eric Kutil falling asleep at the wheel and flipping his car trailer, and decided to pull onto a back road to call it quits for the night. I finished the drive home this morning. Proper suicide mission haha.

Firebird East is a much sicker track than expected for how short it is. I showed up not expecting much, but it's a blast! Pretty high speed for its size and a couple sections on it require some ***** to stay pinned through. The road surface is ROUGH! Case in point.



This was one of my already two day-old tires, but look at that surface pattern! Luckily we basically only ran three and a half sessions, so it didn't kill my tires too bad.

No issues to report with the car, she plowed all day with no complaint. Only thing I noted was that WOT AFRs were a tiny bit leaner than they were back home. I have to check ECUtek the tables for anything related to IAT/CLT enrichment, as I'm not sure if either are adjustable and affecting fueling in some way. I'm also considering just running the fuel system in full time closed loop. I'll check into it and continue messing with it this week.

 

Congrats! Great result, and solid times for your first time at East, and in summer conditions no less!

It really is more fun to drive than you would think looking at it on paper, with a couple of challenging corners. Turns 6/7 require a lot of commitment to be fast. It's a shame the facility is so lackluster, and having the pits in the infield is kind of a PITA.

Crazy Firebird East story: this was probably 20 years ago... I was racing bikes back then and going around turns 6-9, I felt a huge vibration in the bike, accompanied by a low frequency audible rumble I couldn't quite place. It freaked me out, but went away after a few seconds, so I continued my session. A few laps later, it happened again, so I pulled into the pits to check the bike out. That's when I realized out they were running the top fuel boats on the lake, which is right next to East. What I was feeling on the bike was the fuel boats making a pass on the lake 300 yards away!

 

Thanks, Roda! I was looking at various times before going out there to try and gauge where I'd land. Probably not the best idea as it's easy to set yourself up for disappointment doing that, but I'm happy with what I was able to produce! I'm going to come back out for the Saturday event at the neighboring track there in December as well.

Agreed with you on the challenging corners as well. 6/7 was a bit nerve-wracking to go curb-to-curb on. I don't think I ever got to the point where I was confident to get on throttle early and stay there with zero let-off at the exit. The following complex right before the final hairpin was pretty hairball as well. I found I could stay flat all the way after turning in for the first left, but would have to lift right as the car transitioned into the following right. To say that unsettled the car would be an understatement haha.

Luckily we pitted in the dirt parking lot outside of the track, but yeah, still not much in the way of amenities. Plus the dirt lot meant that cars were tracking dust onto the final corners of the track every session.

That's rad how you could feel the boats going by even being separated by that big dirt barrier out there. I saw the lake on Google Earth and thought there was no way that was a drag strip haha. I'd kill to watch a couple top fuel boats make passes out there.

 

Never heard that story about Eric before. Good on you for playing it safe.

Did that C5 give you a point by? I don't imagine you'd be able to beat him in a drag. Good lap, looks like fun.

At our local autocross venue we get tire graining similar to that. When we were in Winnemucca I was really confused because my tires were super smooth instead of torn up.

Not the best example, but coincidentally I took this at our last event.

 

The Eric story is crazy. I think it was two or three Summers ago. Heading home from a race, he was sleeping in the passenger seat and I think his dad fell asleep at the wheel. The truck and trailer ended upside down in a ditch but somehow neither of them were injured and the car only needed some moderate bodywork. It was the best case scenario for them obviously, but I didn't want to tempt fate myself.

No point by from the C5, the mighty 2.5 had him dead to rights in the straights. GM be damned
Nah, he let me by. I didn't get the point by but it was open passing so I figured he'd let me by once he saw me get the inside. Bit of a bummer though as that PB lap could've been even faster!

I can see how rough that road surface is, even though it's out of focus. Yeah, that's some proper bomb-holing!

 

Damn y'all ride some big *** bikes. I've been thinking my Santa Cruz Blur has a shitton of travel and isn't efficient enough already, to the point where I'm just riding my road bike again lmao

 

Different strokes for different folks, right? My background is riding downhill bikes so I suppose that might lead us to different perspectives on travel and efficiency haha.

So the final NASA SoCal race before summer is at Buttonwillow in two weekends, and I'd like to get beaten less badly by the two guys who usually dominate my class. After adding the airdam to the front of the car, my once 4" front splitter became a ~1.75" front splitter. With the airdam and resulting shorter splitter, I feel that overall front end downforce wasn't affected noticeably (although drag was definitely reduced). This is fine, but the car has still a bias toward understeer at higher speeds. Given this, I think I can gain some free overall traction by adding more front end downforce. The NASA TT5 ruleset allows for a splitter with 4" maximum protrusion from the bottom of the car's bumper/airdam, so I started cutting a bigger splitter this week to fit that parameter.



Cutting a splitter is so much nicer the second time around. I just traced my previous splitter onto a fresh sheet of birch and cut it accordingly with some extra lip on the front. With the previous splitter overlaid on the new plywood sheet, I drilled all the necessary holes in one go as well.



Transferred over all of the L-brackets I used to stiffen the previous splitter, mounted it up, and trimmed it after work yesterday. I coated it with spray-in bedliner this time as well instead of regular spray paint. Pretty stoked on how it came out. On my NA, going from a 4" to a 5.5" splitter produced a noticeable downforce bump, so I'm hoping this 50+% increase in protrusion should do at least the same.

Despite side skirts not being legal in NASA TT5, I've also been scheming on making a bigger set than the 3" skirts I have for non-race weekends. Procuring a 4x8' sheet of 5mm alumalite probably isn't the hardest thing in the world, but it's just enough of a pain that I haven't really pursued it as a project. I've tried to purchase one outright from some of the sign shops/suppliers around here, but they all want you to sign up as a vendor, or submit a quote request, etc etc. I reached out to a couple and never heard back, which is unsurprising because I'm sure they're set up to sell in much higher volumes.

Anyways, I had a facepalm moment while thinking about this a month ago. My dad's worked in high sterility wall and ceiling panel sales for 30+ years, and could probably source me a sheet of alumalite or ACM. I called him up and sure enough, he was able to get me a sheet of whatever I wanted. "All of those companies you contacted are probably buying the stuff from us anyways." Lol. I was going to make the new skirts out of ACM initially, but ended up going for 5mm alumalite instead. The sheet showed up yesterday. I took some measurements and started chopping it up.




My current side skirts are 3" and have almost zero protrusion from the bottom of the door. I want these new ones to extend all the way to the outer edge of the wheels so I can build some rear spats that fully cover the tires from incoming air. A quick measurement showed that 8" is what would take to make that happen, so I cut out two skirts in that width and hit them with some primer and gloss black spray paint. I'll make them a prettier shape and bolt them to the car next week.


Sometimes my fiance sees the photos I upload to this forum and gets visibly confused at the things I talk to strangers on the internet about. We actually laugh about it a decent bit, it's kinda hilarious when you take a step back.

Today, I was going to work on the skirts on my lunch break but got to do some tune diagnosis instead. I did a pull on my way to work and AFR's pegged at 14:1 throughout the whole rev range. No issues elsewhere, fuel trims at cruise and idle looked unchanged. Man, Friday would've been too easy if I didn't have to diag something on my car. I dove into it on my lunch break, comparing the log from this morning to a log from two weeks ago. My initial hunch was that I had an issue with one of the fuel pump o-rings again, and was losing pressure at high loads. The datalogs disproved that, though. The engine was running lean at WOT, but MAF readings and commanded injector pulse width were lower this morning compared to a log from two weeks ago. MAF at redline was 110g/sec compared to 130g/sec previously and pulse width was hovering around 5.3ms compared to 5.8ms before. Ok, it's probably an input error of some sort, or maybe incomplete combustion. I pulled the MAF out. It looked pretty clean but I sprayed it with some brake clean to be sure. Did another pull, still lean.

Next, I was going to do a quick ignition system check. The ECU always sets a P0300 code for random misfire due to the chop from the bigger cams at idle, but I also had a P0304 today for a cylinder 4 misfire in the system. My NPT breather in the valve cover had worked its way a little loose over the weekend and a small amount of oil had pooled in the valve cover valley. My next thought was that some oil might've worked its way into the spark plug bores and was causing a slight misfire at WOT. I pulled the coils and no dice, all the plug bores were perfectly clean. I started popping the coils back in when I noticed something else.


Ahh yep, that'll cause a low MAF reading.

Tear forming in the intake tube behind the MAF, right before the throttle body. I should've caught that sooner and/or done something to prevent it. The TDR air intake I have runs straight forward into a hole behind the front bumper, but only uses an ABS plate to prevent it from moving around. There's no fasteners on the filter end of the intake that allow it to be hard-mounted. So as you're driving, the intake's allowed to move around left and right a little less than an inch or so. That definitely shortened this poor elbow's lifespan. I ordered a 90* silicone coupler and sealed up the hole with some RTV so I could get the car home today. As far as failures go, I'll take ones like this all day. $20 for a coupler isn't bad at all, plus it'll look cooler than the OEM accordion tube the car comes with.