Can you look over my tune? 2.9L M20 Turbo

[SGT StudMuffiin]

Hey guys, so I’ve almost got my car on the road. A little while ago I was on the dyno and the headgasket blew due to an improper installation. I just want to make sure that the actual tune itself is safe and didn’t likely cause the failure.

My engine setup is a 2.9L M20 with M52 crankshaft, VAC rods, 9.0:1 CP pistons, ARP hardware and studs, VAC cutting ring headgasket, and a built head.

I’m running a MS2PNP with wasted spark on US 91 equivalent fuel at around 13psi wastegate pressure.

Here are some screenshots I took from TunerStudio.

If you have any questions let me know. Any help would be greatly appreciated


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[tschultz]

How did you generate these curves? A lot of red flags with each map you shared.

And before we comment on the problems, what are your trigger/toothed wheel settings?

[ForcedFirebird]

Your timing table is too large for 10psi, and you are pulling wayyyy too much timing if your crank sensor setting are correct.

You are dumping an immense amount of heat into your turbine.

The timing table should look pretty stock below 100kpa

[SGT StudMuffiin]

How did you generate these curves? A lot of red flags with each map you shared.



And before we comment on the problems, what are your trigger/toothed wheel settings?

I’d also like to add, that my tuner said that the car is like 99% tuned, we didn’t get to start on any power related stuff, just making it safe.



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[citizen_insane]

Agreed, that ignition table looks extremely retarded (in the technical sense). VE table looks a bit high on the top end, but that could just be due to your specific setup. If you're running electronic boost control, please also post your boost map.

Have you verified your engine timing w/ a timing light? I realize it's not easy to do on the M20. On my car I made a mark close to the VR sensor pickup and then used an adjustable digital timing light to verify at multiple operating conditions.

[ForcedFirebird]

Have you verified your engine timing w/ a timing light? I realize it's not easy to do on the M20. On my car I made a mark close to the VR sensor pickup and then used an adjustable digital timing light to verify at multiple operating conditions.

The m20 has an OlT mark on the timing cover and crank hub. ;)

[citizen_insane]

The m20 has an OlT mark on the timing cover and crank hub. ;)

The one that you can't see because of the packaging of the rad/shroud/coolant tubes? I'm aware :D. Wasn't able to get a good read on my car by trying to use that mark.

[SGT StudMuffiin]

Agreed, that ignition table looks extremely retarded (in the technical sense). VE table looks a bit high on the top end, but that could just be due to your specific setup. If you're running electronic boost control, please also post your boost map.

Have you verified your engine timing w/ a timing light? I realize it's not easy to do on the M20. On my car I made a mark close to the VR sensor pickup and then used an adjustable digital timing light to verify at multiple operating conditions.

It is only on wastegate pressure right now, and my tuner said he did verify the timing with a light.


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[e30davie]

First major red flag for me is negative timing values....this does not pass the sense check.

And you said it was a 2.9L but you have 2693cc in the settings?

[SGT StudMuffiin]

First major red flag for me is negative timing values....this does not pass the sense check.

And you said it was a 2.9L but you have 2693cc in the settings?

Yea I wonder if my tuner thought it was a 2.7. Does that make any difference though? If figure when you’re tuning the car it’s going to react to inputs and changes regardless of displacement, unless of course, tunerstudio changes the parameters based on the given displacement.


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[ForcedFirebird]

Timing is user-defined. It will not be based on any of the engine values.

Fuel on the other hand will have slight changes when changing the engine values.

[SGT StudMuffiin]

Timing is user-defined. It will not be based on any of the engine values.

Fuel on the other hand will have slight changes when changing the engine values.

I tried PMing you but it says your inbox is full


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[ForcedFirebird]

I tried PMing you but it says your inbox is full


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Yeah, been conversing with a lot of people due to my garage sale at the shop.


Cleared it out. The email in my sig is also valid. ;)

[LowR3V'in]

Glowing manifold at 10psi and 15hp gains total from n/a :P

[pazi88]

First major red flag for me is negative timing values....this does not pass the sense check.

And you said it was a 2.9L but you have 2693cc in the settings?

Those negative values are on the area that engine never reaches. So it doesn't matter. But for me it mostly looks like that the tuner took some readymade m20 turbo map from internet and retarted boosted section of the map by 3-8 degrees to make it "safe" and called it a day.