Hello everyone, this is my first post on miataturbo and i typically love the results I see here. I had an issue with my car and was curious on what I should do to either fix or troubleshoot my issue.

I have noticed my boost has not been hitting the 8psi and has gotten farther and farther from it and I am currently at an average of 6.5psi. I have a data log from August 2023 and I was hitting 8 to 8.5 psi and i just data logged and max boost i made was 6.5psi. I am hoping it is a simple boost leak as my intercooler piping is a little questionable. I am not sure what you can pull from seeing my data logs using MegaLogViewer but I have attached both files. I also attached my tables from tunerstudio and people have told me the tuner did not do the best job as on 8psi I only made around 130hp.

Any ideas of what could be the issue or something i should look for? I am taking my car home from college soon and re-doing all my intercooler piping in hopes it is leaking from one of the connections.

This is my afr, fuel load, and ignition tables, and I dont know everything about these but just from looking at some of the values, it seems off.

 

At first glance:

Your AFR table is scary AF. Either I'm missing something, or it's only scaled to 100kpa. What are the targets in boost?

Your IGN timing table looks super retarded. The 100kpa row is a solid 6* (or more) retarded, same with all your boost rows. Start reading around if you wanna find some good examples, or get a good dyno tune where the operator actually tunes to MBT.

As for not holding boost, I recommend a boost leak test, always. And of course double check all the turbo HW, etc. and make sure the turbo isn't falling off or leaking there.

I'm no pro though, YMMV.

 

Yeah I was told the KPA is supposed to go above 100 when in boost, and that it looks like he didnt touch the afr table and just added more in the fuel table. I am saving up for a tune from some one with more of a specialty in megasquirt who was recommended called Advanced Dynamic tuning. But since i don't know too much of the tables I don't know how bad it is .

For a boost leak test how would I go about that? My guess was too get soapy water and spray all my connections and tighten up the turbo to the headers incase it leaks there.

I have the HKS SSQV and have heard there's plenty of fakes going around and that the fakes tend to leak as well but I am not too sure how to identify a fraud, it was purchased from Throtl Preformance https://throtl.com/products/hks-ssqv...ks71008-ak001?

 

https://www.siliconeintakes.com/inta...essure-tester/

 

The VE Table looks completely untouched, like not even autotuned. Surprisingly your AFR's in boost actually look reasonable.

Cruise AFR's are centered around 1500 RPM? If you're hitting your targets, which I doubt given how smooth the VE table is, you're going to be cruising on the freeway at 14 AFR or below. At 80 MPH (assuming a 5 speed + 4.3) you're targeting 13 or below.

Idle is at 16+ AFR.
TPS goes to -15% at some points and never gets to 100% (IE not calibrated properly)
At one point you're holding steady around 3300 RPM and your AFR swings between 11.5 and 16.8 over the course of a couple seconds.

I'm assuming you are just running wastegate pressure and don't have electronic boost control?

If you can post the tune you'll get better feedback then just the datalogs. I hope you didn't pay too much to this "tuner". Was this a remote tune from somebody on Facebook by chance?

Disclaimer - I am also not a pro

 

Okay so for the TPS I had touched the flat head screw on the throttle body a while ago when the idle was low(before tune) and probably should set it back, I think the tune is so clapped that if its any closer to zero it would die in idle. The tuner told me he knew what he was doing but I did feel it wasn't as professional as I was expected, should've trusted my gut.

Yes the turbo has an internal wastegate that was supposedly set to 8psi, which I was hitting but not anymore.

I paid the guy $300 for the tune but my plan is going to a place that charges $800 and I was told the guy is really good and I think I am going to give him the default tune so he wont try to fix my current tune.

 

If you mean the set screw that controls the idle, that shouldn't affect TPS readings by the ECU.

I'm curious who this tuner is now (not that it matters). $300 seems absurd for a tune that doesn't even have AFR targets in boost. Honestly a lot of free base tunes would probably be safer/better than what I've seen so far.

 

Also, having said that, I doubt the tune is causing the turbo to spool slower. I was thinking maybe the boost control strategy had changed, but it sounds like that's not at play.

 

Also the ignition table is junk. Please flame this “tuner” for stealing your money.

 

@kep Pitchfork time?

 

Yes, please call out bullshit tuners to save your fellow man.

 

For real! $300 down the drain but that's what I get for cheaping out Place is called Atmoic Franks Tuning, he seems to be more on the honda platform but I guess his knowledge didn't transfer to megasquirt

 

This is basic knowledge every tuner should have, even if the person is used to other platforms. I don't know how people can make a living with that ****.
Most of the experienced guys could tweak your tune to "drivable and safe" in 30mins.

 

So when I get the new tune should I just get a fresh start with the default tune or bring in my current tune and have then fix it?

 

Can you post the full tune file here? I'm mostly curious to look at it.

If your car is mostly stock as far as wiring, sensors, etc... I would think starting with a fresh base tune would be the way to go. I think a good tuner would be able to look at what's there and figure out the best path forward.
Based on what you've shown so far, I'd think you want to revisit the whole thing and start from square one. Who knows what else is setup incorrectly?

 

I'm not sure but you might find a good base tune on https://trubokitty.com/#/tune

 

Yeah ill upload it now, other than aftermarket coolant temp, air intake temp, 02, TPS is aftermarket because my 91 didn't have one, and obviously the ecu are the only significant wiring I have done. I set up the injectors in tunerStudio, and some of the instructed things that were needed to be done but for everything else does the tuner touch or is it assumed I have set tunerstudio up and all they do it touch the tables?


Okay so I have a few tunes that are in my main folder for my tunes, Ill add both, could you tell which is better/ safer? I am currently using the one called Boosted_Tune(from the pictures above).

UPDATE: I saw there is compare tune option in TS so I tried it, CurrentTune and Boosted_tune had no differences. But there were 5 major differences in my boosted_tune and AFtuning, I went twice as I had a blown header gasket the first time and I don't know which was the first half tune and which is the full tune from the second tune.

 

As expected, you don't have incorporate AFR targets enabled, so it's basically a reference table, it means nothing to your tune as long as the fuel table makes reasonable AFRs. It should be enabled so it starts to affect fueling, and EGO can be enabled and correct to reasonable targets.

There's still a lot wrong with the tune, ignition table specifically is crap, and looks like EGO is enabled, so it will try (under 70%tps and below 90kpa) to track those terrible targets. Main issue is you'll have **** mileage.

 

You said you're running 8 PSI, which I would assume puts you around 165 KPA, but it looks like your overboost protection is around 150 KPA. Does the car cut out or stumble if you do get deeper into boost? Maybe not an issue right now if you're only building 5-6 PSI, but if you get the car spooling properly I think you're going to start hitting that.

I would also be curious to hear what octane you're running with this spark map.

 

Right I do see that, I havent noticed it cut spark before, hit 10.2 psi on the boost gauge once for a little bit one time and unordinary happened.
I got tuned on and only use 91 octane from Chevron.