OK folks, time for an update. You might think I've abandoned this car to work on an rx7 or something, but no, I've basically been working on it non-stop.

Let's pick up 4 weeks ago where Ieft off. After pulling my MS and wiring it for CAN, with the idea of running @redursidae 's SPARTAN wbo2 controller, soldering on the board to jumper CANL and CANH to the correct outputs (trubokitty ms3 does not come with this setup) I was ready to slap that WBo2 in. Not a ton of work per say but a bit of a project tearing the MS outta the car and figuring out all that jazz and running a few wires. Then @redursidae messages me the night before we're gonna tune this thing and lets me know my firmware doesn't support CAN. Anyways no fault of his, to be honest, I shoulda done more research here myself. After some debate on upgrading the FW we decided that the changes would require a full retune (due to changes in idle control, boost control, e85 flex algorithms, etc.), and we were at that time hoping to get away with just tidying up fuel. So after that work, no fancy new CAN wideband. Meh, but OK, let's tune this bitch!

Now, 3 weekends ago, @redursidae came up to tune the car (and drop off some more miata parts for the miata ecosystem I've apparently started up here). Parts included sway bars and roadstersport exhaust for the aforementioned 00se my coworker now adores, an oil cooler sandwich plate and some other misc stuff for my silver NB2 project (future low HP track car), and some more misc stuff that Ricardo's wife made him dump (I kid, i kid). Anyways good deal on the parts and I get to see one of my favorite buddies, who also happens to be my tuner (I've mentioned this but his attention to detail no things like this far surpasses mine, so I happy pay him for his awesome services - hit him up if you need help!)

We jump into tuning right away, lots of changes between the seq fuel and PTX turbo change making my old fuel map off just enough that re-tuning it in person was the best option. And he was willing to drive up here to do it, what an awesome dude. Anyways we get the car dialed in in my garage idling better than ever, do a little tuning session on the way to a coffee shop about 15m away, review logs there while drinking some dank espresso's and flash some more changes. Ready for boost, we thought.

Then we fire the car back up after sitting and start driving it, and immediately Ricardo notices something is off, it's wanting another 10-15% fuel which is no small amount. Now mind you this car has always had a discrepancy between "warmed up" and "heatsoaked" even though the CLT sensor shows the same "up to temp" 180-190* temps. It's just something I've always fought, and now it's glaring Ricardo in the face. I also noticed some mean rev hang and take it back to the shop to debug some of this funkiness. Annoying because I thought the car was DIALED for tuning.

Anyways back at the shop we debug, I'm checking grounds, testing for vac leaks, etc. I find a TPS ground that's flakey (my fault) and fixed it, which actually helped with some strange TPS noise we'd see from time to time. Nice! No vac leaks were found though.

Back out and road tuning, no dice and nothing was different fueling wise. The car still wanted that extra fuel, and only after heatsoaking. Ricardo knew something wasn't right, I kinda blew it off, "man my car has done this BS for a while, we'll make up for it with EGO and whatever other corrections we can use to fudge it". Plus I'm antsy to finally feel this PTX2860 sing, so we go out to mexico for some street tuning.

Street tuning goes great, we get fuel dialed in pretty quick and start working on boost control. We find nearly immediately that this 6.5PSI wastegate on the PTX isn't going to hold, it creeps to about 11-12psi by redline with no boost control. That's alright, I didn't really build this car to be slow - though i did have some dreams of detuning it to slot into some other racing classes (and improve as a drive on a slower car), but it is what it is. I considered porting it when I had the turbo in hand, but I just couldn't bring myself to take carbide bits to that brand new housing, get shavings everywhere, possibly nick something I shouldn't etc. and opted to just slap it on.

So pretty quickly I tell Ricardo let's just accept that it wont make less than 12psi and tune the boost control to ramp it up early and embrace 12psi as the "low boost" setting and go from there. And holy ****, this thing on 12psi feels hotter than the oldskool disco potato on 15psi. What a ripper, it's gotta be cracking 270whp on 12psi already.

Once we get the boost control and fuel how we like it on 12psi, we opt to turn up the wick. Coming off of a broken transmission and a mega wrenching session I opt to target 18psi for high boost instead of 20+. And probably a good thing we did, because this turbo holds 18psi to redline with minimal duty cycle, lots of overhead, and no heat. We did an 18psi pull in 88* weather and saw 92* IAT's after a 3-6th FULL PULL. And coolant temps are barely above thermostat around 180. The cooling stack is working exceptionally.

Anyways we end up making some great Jam, for sure 330+ by seat of the pants (it made 315whp on the old turbo and it's markedly faster), maybe I'll get a virtual dyno to prove that, or toss it back on a dyno, but all you gotta know is tihs ****** is fast. And picked up 5-600 RPMs of spool everywhere, with crazy response like i've never experienced.

I'm still getting used to the 6 speed at this point, and while it shifts great I do tend to have issues with 4/5/6 or 6/5/4 for whatever reason. At some point I missed 5th and grabbed 3rd, caught it barely with the clutch but not before we saw 7800 RPMs on the log. That scared me a bit, to be honest, but the motor was fine and 7800 isn't too bad in the scheme of things I guess.

At the end of the day the fueling discrepancy never set well with us, and the next day when i drove the car it was really noticable. it would get up to "temp" ~180ish and the tune would be lean (ego was putting in work here), and after enough heat got into it (some boost) it would finally get hot and want 10% more fuel.

Crazy. So I started this thread: https://www.miataturbo.net/megasquir...soaked-110543/

Some awesome discussion there, and while nothing specific in that thread tipped us off, it did have us really thinking about the issue. Most cars would need more fuel when heatsoaked, not less, which gives us a weird inverse curve that is really hard to tune for. I.E. as the car warms up enrichments trail off > CLT hits 180* and no more enrichments, **** is LEAN, drive it for another 15 minutes (CLT still shows 180-185) and bam it wanted more fuel again.

Ricardo asked me if my CLT was accurate, I told him It seemed sane to me. It was always close within reason, though I never scrutinized it, and it showed about the temps I'd expect once warmed up (with a 180* thermostat). Thankfully he checked a cold start log. CLT was 8* warmer than IAT in that log, so he urged me to look into that a bit. Next morning I check it, and sure as **** 8-9* difference, with IAT's showing 74 and CLT showing 80ish. Then I got home after work and checked again, this time it was ~11* off with IAT showing 79 and CLT showing 90*. Damn!

Somehow I missed calibrating that sensor when i went to the MS3. Thinking back I really don't know when, why, or how this happened, or how long it has been like this. Even on my MS1 I don't recall having to calibrate a CLT sensor since it just came as a PNP for my car and just.. worked. Onto the MS3, I don't know that I ever calibrated that. The IAT sure, I had to tell it I have a GM sensor, but CLT I can't say. Or maybe I did and I chose the generic "mazda" calibration (not the correct rx7 s4/s5 calibration) and it was close enough that I never caught it? I really don't know, I feel like it being a PNP unit for my 90-93 car it should have just been set correctly on the trubokitty basemap I started with, but clearly that wasn't the case.

 

Now, how big of a difference does this make? Well, apparently a huge one. After changing the calibration on that sensor it was reading correctly, but fuel maps were wonky. no good at all, which effectively threw our tuning session out the window. it really does suck, back when i tuned my own **** it's something I'd just deal with, but paying for a tuner (a damn good one, at a reasonable rate!) made this hurt a bit. But we press on, and Ricardo is a true homie and has thrown tons of his own personal time at my car as if it were his own, without charge. Can't speak highly enough about that. But still sucks to light money on fire tuning with bad sensor calibration, which kinda made me a sourpuss and maybe why I've avoided this thread for a bit.

Now with the sensor calibrated, we can see the issue. Here's a log snippet 50+ minutes into a hard canyon drive boosting up hill.




As you can see the "yoyo" effect of the coolant temp is massive. it goes from 190* down to 160's and back, repeatedly, in the middle of July driving up a mountain pass boosting and passing cars. The old sensor calibration must have been non-linear, or something, because this is something we hadn't seen.

My theory is that the CLT miscalibration wasn't linear, or something, in the operating temp range and it just didn't have the resolution to see this. The way the sensor was calibrated before you might see it move between 180-185 but nothing like this. The tuning issues we're fighting are because in reality the car wasn't fully warmed up, but was showing warmed up according to the sensor. The now properly calibrated sensor shows me a major flaw in my coolant reroute setup which remote mounts the thermostat 18" from the head with NO BYPASS, tstat opens CLT drops to 160's, closes back up to 190, etc. etc. maybe forever on a cool summer day in the canyons (68-70* day).

So I parked the car and made another order to SuperMiata (thanks guys!), because even though now we have the sensor calibrated and could tune for this, I don't like it. My newly engineered cooling stack works so well that with this reroute/thermostat setup I'm overcooling the **** out of the motor. Likely not an issue on track, but I wanted to get the car sorted mechanically in all ways before re-visiting the tuning.

 

I got the SM reroute in last weekend. What a nice kit, I really do like it, well thought out and I had no fear of it leaking after I installed it. My old reroute was circa 2008 tech (and that's around when I bought it) and consisted of a BEGI reroute spacer, a kia waterneck, a suburban radiator hose, with a remote thermostat in line. I always feared of this one leaking anytime I'd R&R it and often it did leak if you didn't get everything just right. Also if you overtorqued it it would snap the kia waterneck in half, which I've done.




With the 195* thermostat the car warms up and never drops back under 180 after that. Never once did I hit WUE after the car got out of warmup. Well designed kit, I'd say, and with an efficient cooling stack (hella ducting, SM rad, etc. etc.) the 195 tstat is the place to be.

Since all recent tuning data is basically out the window with all this, I also went ahead and loaded MS firmware 1.5.2 onto the ECU and we're re-tuning for that. We might even jump to the latest 1.6 stuff at this point, to be determined, but CAN is back on the menu. Ricardo even offered the controller for free, because he's a good friend, or out of pity, or something like that.

Here's a current example log from today. This is the same drive about the same amount of time into it. Sure it still "yoyo's", which I think is very typical of any car with a thermostat, but look at the highs and lows. now it's jumping between 185* - 195* instead of that crazy 160* - 190* flux that was dropping it into WUE with the remote thermostat.



We're so back, baby! And no weird lean spot in the map anymore. Ricardo is the man and he's working with me to get this retuned before the next track day. The last revision he sent me is already really, really good for a remote tune. Excited to see where we go from here!

 

Oh dear! I know I have posted somewhere here about the grief that a failing coolant temp sensor caused me and my tuner in the leadup to, and during one dyno session, before we either twigged it was the sensor, or simply threw another sensor at it in desperation (too long ago to remember the details). But I remember the pain, and the solution!

So my recommendation is that you junk that CLT sensor, never mind you have (had?!) a working calibration, and start with a new one. You say you placed an order with SM, I am hoping it included said sensor ...

I must have missed the thread on this issue linked in your post, or I would have made this suggestion there.

 

It sucks to have wasted all that time, but the ultimate result will have been getting a major issue resolved, and the car working much better. I do know how that feels, but it's a good thing in the long run.

 

It has been a wild ride this past month but the positive side is that we're back to making progress and the car is fast as hell with this new turbo. After we finished doing pulls in Mexico and were hanging out at Nate's place we could both hear the sound of the turbo spooling. It's loud, but it slaps.

I appreciate your patience, working through the hurdles and being a pleasure to work with. Thanks for the shoutout too .

 

Damn, quite the saga! That’s frustrating as hell but made for a great morning read, so thanks for that, lol. Glad you guys got it figured out. I’d just reframe that “wasted” time as “diagnosing” even if It didn’t seem like that in the moment.

I had a similar tail-chasing escapade happen with my NA for a bit. Once a lap at WSIR, the boost controller would cut out for a split second right on the front straight. Did a bunch of tinkering with the controller wiring and found nothing. Ended up being a loose ground at the back of the head that was causing enough CLT noise to drop the reading below my high boost threshold of 175*F intermittently. Didn’t figure it out until a week later lol.

@redursidae is a smart dude! I’d pay to have him share tuning tips over some bitchin’ coffee

 

Thanks for the comments, folks! That wall of text was kinda hard to write (and probably even harder to read), I've been putting off an update on this thread for too long so it was kinda a mega-dump. I didn't really proof-read it either, it was more of a brain dump. So thanks for bearing with me.

I'll consider replacing the CLT, though since it's been re-calibrated it has been rock steady. I have confidence in it but will keep a close eye on it.

A few pics to spice up the thread. Wing makes a nice workbench:



I know some are hesitant of dealing with RTV on the reroute, but ironically I'm more paranoid to put one together without it. I actually love that this reroute goes together with just RTV and no gaskets. Makes it so I can service it in my garage anytime without having to order parts. The old RTV was a slight pain to get off behind the head, but honestly only took maybe 30m to get it perfect and cleaned/ready.



And I've got the car back on DD duty this week. Day 3 of driving it to work and lots of back and forth, tune revision #3 for the week. Ricardo is a boss.





Having Ricardo on my team for this car is huge. it's allowed me to make some major changes to the car without even thinking about the tuning aspect, knowing we'd (he'd) figure it out. He also explains everything to me and lets me absorb knowledge which comes in handy since I've got other cars on standalones and somehow have become the local tuner here for my local miata friends. I can make a car run, safely, and get good drivability out of it. But nothing like what Ricardo does with his OEM-like smoothness on all aspects. And for other projects, like my FD, I know he will be invaluable helping me with that.

Aiming to hit the next trackday in Sept. Also wanna get some 4th gear virtual dyno pulls once we get this thing sorted back on high boost and get some vids for y'all. The car really is a weapon, the more I drive it the more I can feel the massive differences/improvements. 30% throttle, 3000 rpm, 8+psi of boost. It's nuts.

 

If you don't stop talking about how great that 2860 is my wallet is going to be complaining soon

Out of curiosity, how did you check the calibration for the upper temps? Went back and reread some of the post. Sounds like you're just using the Rx7 cal table. Almost makes me want to pull my sensor and measure the resistance at various temps.

Those tuning issues can be so tricky to track down. I had an IAT sensor issue at one point and the Link went to the programmed "error" value which was set to a ridiculous value. That made the car go into a part of the map where it was increasing fuel like crazy.

 

If you want 2560-like spool with a ~375whp capable turbo nothing comes close to it in terms of value. I'll have to get some plots pulled up and compare the spool for you. It's night and day from my old setup (which I actually loved).

 

That's pretty much where I'm at. If I hadn't already got the t25 setup I might opt for a 25-550 clone but I don't see much of a point swapping everything out again when I don't really need that much power. The 2860 seems like it would be a happy medium.

I've looked at Andy's charts comparing the 2560 and 2860 and it's pretty much exactly what I'm looking for, especially with the added headroom for pump gas.

 

I have nothing of substance to add to the discussion other than you're the reason I ordered the ptx2860 gen 2. Hearing you rave about this thing has me super excited. I'm making a switch from my MKturbo setup to full kraken + 2860 gen 2. Both are on order. The mkturbo kit was truly great, but I have rods and 8.6 pistons now and im ready to turn it up. How much were you making before you switched to the 6spd?

 

Hey! So I was making 315whp/280wtq on high boost, 265whp on low boost on the 5 speed. Ran it like that for about 5 years, with lots of track use, but also general mechanical empathy.

I also highly accredit my old/laggy gt2860rs for helping keep it together. It was full song around 4400RPMs and made a lot of top-end. The ptx is hitting full boost a solid 500+ RPMs before that. It definitely feels harder on the gearbox so I bet it would have eaten a 5 speed earlier on a more aggressive turbo, even a 2560 at full song.

I was just ripping the car again today. What a machine, it's a ripper even at 160kpa target (track boost levels). I need to dig through some more logs for some better examples, but here's a snippet from this week (we've tightened up boost control since then):



And a snippet from the old turbo



These aren't fully apples to apples comparison, but you can see the spool curve on the two (just look at the shape) and RPM's when they reached 160kpa. Also keep in mind ambient baro is ~78kpa around here typically, so my 160kpa target is ~12psi. We went with this for low boost because even if you try and run less it creeps and hits 160 near redline (on ethanol this car has always caused boost creep like that), hence the suggestion for wastegate porting if you wanna make lower power or tq.

Also keep in mind again, 7200ft elevation. You sea level guys are gonna spool the **** outta one of these. It spools so hard that we're using EBC to try and flatten it out a bit on higher boost, but on partial throttle even with no EBC duty (just wastegate) it's spooling like 8psi at 30% throttle and 3200rpms. This would be a stock rod eating turbo for sure, and again, probably a 5 speed muncher.

I'll have to dig up some high boost examples and maybe some transient throttle stuff, cuz it's a whole diff car now.

 

Everything Ricardo @redursidae has said regarding my car has been true over the years. There may have been moments I've doubted him but honestly if this guy looks at your logs/msq and tells you something, you should listen. I'd like to come up with a list of things we've fixed, thanks to him. Off the top of my head:

• Flex sensor reading incorrectly due to being installed on return line, at WOT not enough fuel is returned, eth % drops substantially during an extended pull resulting in less fuel being injected, timing being pulled, etc. He caught this in our first in person tuning session over 2 years ago. Kind of a big deal. I plumbed it on the return line as to not "restrict flow", or have more of a chance to leak being on a high pressure side. Wrong. If you pushing your fuel system hard the return line is likely a trickle at higher boost/extended WOT.
• Alternator was dying, this was closer to 2 years ago when we first started tuning this car together. He pointed out inconsistent low voltage when hot. Repalced alt with a FD alt and voltage stable as a rock.
• **** idle and throttle response. Solved with Seq fuel. I thought based on everything I read that this wouldn't be such a massive improvement, but it was. Turns out my batch fuel was wired out of sequence, which probably made this upgrade a bigger change than most would see. I think. He was pushing me to go to full seq fuel since I met him.
• Urging me to upgrade FW. My old brain ms3x was on 1.4 FW and we're now running on 1.6 FW. Partially this was required for CAN support, but we gained lots of stuff with closed loop idle control, boost control, flex fueling behavior, etc.
• Noise in my TPS. Turns out I wired it hastily and never made that permanent. He saw it, pointed it out, and I was able to quickly fix it. Easy fix, with some solder and heatshrink no more noise.
• Coolant sensor mis-calibrated, he caught this after we were debugging a strange issue. It was only off by 8-10*, but 100% was mis calibrated.
• The current issues led us to grounds, which I deep dove on. Being able to consult with him I'm finally at a point where I feel like the grounding schema on the car is proper "star" grounding with important sensors grounded to the ECU, the ECU grounded to the block in the proper spot with other sensor grounds, and noisy grounds such as coils and wbo2 heater moved away from that. I also have a single ground point from the engine to the chassis, at some point I had multiple which I now know is no bueno and can cause voltage offsets and loops. I also cut the "sensor ground" wire (black/green) on the stock NA6 wiring to help with noise.
• With the tune more dialed than ever we were still seeing obvious discrepancies and inconsistencies, which frankly was depressing. After much back and forth and obsession over the car the last few weeks (months?), he urged me to upgrade my o2 controller. And even gave me a Spartan3 controller to try, and gave me his own backup sensor to try (shirt off his freakin back, what a homie). And helped me wire it in with proper sensor ground to ECU, and CAN input to the ms3x. This fixed my entire issue and recent obsession of the car operating differently when first up to temp vs "heatsoaked". Honestly another thing he called and urged me to replace that I was skeptical wouldn't change a thing, I was leaning towards fuel pressure which I also added a sensor last week and we confirmed fuel system is behaving exactly as expected and is fine.
• While we've exchanged some good cash, the dude has thrown in countless hours helping me debug, sending me revisions, and literally helping me in real time as I'm working on the car and/or helping me fix it at the track that were not billed. He's the real deal and I'm honored to call him a friend and be able to support his business as well.

If you are having issues with your car, hit him up. https://www.ccmoto.net/home

Yes, I'm ******* thrilled with the car right now, it's absolutely perfect and we've overcome so much. One big thing I can say for other people that have been ******* with the same car for 20+ years, is to re-visit the **** you thought you did "right" at the time. My idea of what's right, or acceptable, has vastly changed over the years and it's easy to skip over some of that. I did some hacky **** on this very car 15+ years ago and forgot about it. Also, some parts need replacing/upgrading. I was running the same wideband UEGO controller since 2007 when I first turbo'd this thing and went with the MS1, glad to have that retired for some (somewhat) modern tech. I probably should have done that along with the MS3, which I installed.. in 2018? Time flies.

I'll do a better post with some more info and details on the weekend, but I had to get this out there.

 

If only there were an ECU with a feature to stop updating eth% above a certain injector DC.



The thought is it's still better to put the ethanol sensor in the return line to not restrict the fuel flow, but ethanol sensors are 3/8, and even 5/16 stock miata lines can support up to 500hp, so there's really no need for concern there.

 

Years of that man posting on this site and he never once mentioned he had a tuning/consulting website. What a humble dude haha. It's baffling how many hiccups you guys got ironed out! Though I agree with your sentiment that we should all go through our cars for things we "thought" we did the correct way. I've certainly got one or twelve "temporary" fixtures on my car that could use some refining or cleaning up lol.

 

Shoot, that was unexpected, but greatly appreciated brother. As I've said before, I'm just happy to be part of this car's story and be able to help, and it's also a bonus to hang out with you.

Curly, I've tried very hard to convince him haha. I'm holding out hope that he might reconsider after he sees the difference in the FD .

Zak, I'm not big on advertising mostly out of fear and impostor syndrome. I've only mentioned it a couple of times I think and mostly within a wall of text ha. Nate was my first customer 2 years ago and it's still unreal that he trusted some random dude from the track to tune his car.

 

This one is for @SimBa . I keep seeing his sweet virtualdyno plots and haven't done it in a while. With the car super dialed I decided to see how high/low boost on e85 plots out. Really hard to find an actual flat road around me, the high boost pull ended in a bit of an uphill, it definitely doesn't fall off that hard - tho it does flatten out. Considering it dyno'd 315whp on the old turbo (corrected dynojet) I'm sure this one would be 330+ on that same dyno at the same boost levels.



Also FYI we purposely taper in high boost, hence the lazier curve. It could definitely ramp up harder but I'm more than happy with it. Needa find a better stretch of road to do some more high boost pulls to get a more accurate graph. Also this is at 7k ft elevation so I'm sure this turbo would absolutely freight train at sea level. Car weight is total guess, but it was RIGHT after I topped up with a full tank of e85, so I honestly don't think it's over-estimated weight wise. Full interior 1990 with bp4w, turbo stuff, heavy stage2 intercooler, roll bar, and a full tank of gas. Really needa scale it sometime so I can be more on point with that.

There's definitely more in the tank on high boost, I just wussed out. It's easily holding 18psi flat to red with like 38% duty cycle up top. My last turbo needed closer to 80% duty cycle up there and still ran out of air after 18-20psi. The goal for this car was always 300whp and no more and I'm more than happy with it for now!

 

We gotta get your car to DynoEdge soon. Tim and I are still planning to take his car back once he is done fiddling with the intake and PCV, so maybe you can join us that day.

 

Nice work man! That's pretty much right where I want to be. 260 @ 14 PSI is pretty great, I think that's pretty well within the efficiency range for the turbo too.

FWIW my car weighs right around 2350 with about 1/2 tank of gas.