Twin Turbo '20 GT Dying

[JamesTheriot]

Just recently intstalled a mid mount twin turbo kit on my car. trying to work out the tune to make it driveable.

it seems to run OK where I have it. The fuel trims are off at idle but good when I'm driving around.

Some times the car stalls and there is a sharp spike in the MAF PID right before it dies, the dying usually corresponds with sharp throttle changes too.

This is by no way a good tune in the car but i believe it is safe, starting from scratch here. Thanks for any input.

Attached are my current tune, a log of the car killing, and a log of me driving for a few minutes where the car also dies in my drive.

JAMES GEN3 023. BASE TURBO TUNE -31%MAF.hpt
REV AND DIE.hpl
drive to buffs.hpl

[murfie]

What port injectors are you using? seems to be your fueling issue.

Are you still on stock lift pump/ DW400 and maybe a pump booster?

What is the size of the pipe you have your MAF sensor in?

[JamesTheriot]

The entire fuel system is stock for now. Not planning on anything over 550/600 hp until I get the tuning figured out. Maf pipe is now 3.25" ,original was 3.9375. I took 31% off of the entire maf table because the car wouldn't run before.

[murfie]

Seems to have some other issue then as its still 20-30% rich.

You need to log Mass airflow period to adjust the MAF curve.

Oh you didn't modify the lower part of the MAF curve... you have to do the entire thing 31%. multiply by .69.

[JamesTheriot]

Wow. I didnt notice the scroll bar. I'm going to change it now.

[JamesTheriot]

That was it. Fuel trims are near zero and it runs alot smoother but still dies. I only changed the amount that I could see on my laptop screen. There was a scroll bar for the lower portion of the maf curve.

[JamesTheriot]

JAMES GEN3 023. BASE TURBO TUNE FULL - 31%.hpt
REV AND DIE 2.hpl

New tune with maf curve corrected and a short log of me revving it and the car dying right after a spike in MAF

[murfie]

I wouldn't worry too much about that, even stock sharp throttle stabs like that can cause it to stumble and almost die.

[JamesTheriot]

This is different. I could be driving and move the pedal a little too fast and it would die. It's got something to do with that weird spike in maf.

[murfie]

How much pipe is between your MAF and throttle body? Is it pretty straight or a few bends?

[JamesTheriot]

Under a foot. With one 90. A good bit closer than stock.

[small tuner]

Under a foot. With one 90. A good bit closer than stock.

can you post pictures where the maf located and what is your injectors.

[Plimmer]

Screen Shot 2021-05-30 at 9.22.34 AM.png

Did you mess with this table? If these aren't stock values, then this could be your problem.

[JamesTheriot]

I did adjust that table. Dont remember exact values and my other laptop is with the car, I will be over that way in about 2 hours.

I adjusted it the way they explain to in the coyote cookbook I know that much.

here are some pictures of the maf pipe @small tuner

I dont know how to upload an image directly, would i need a photobucket or something? the original pipe has the maf about 13 inches away from the tight 90 before the TB. My new pipe has the MAF about 4 inches away from the same 90.

[small tuner]

Screen Shot 2021-05-30 at 9.22.34 AM.png

Did you mess with this table? If these aren't stock values, then this could be your problem.

could be.... and maf should be away from any angle to avoid air turbulence

[Plimmer]

Ok, put back to stock then. My 2015 coyote has that table all 0's. I also changed mine as per the cookbook and had issues stalling and idling.

[JamesTheriot]

Thanks. I will try that when I go back.

[JamesTheriot]

Should I have the "blow through logic" set to enabled? What does this do?

[Plimmer]

Leave that stock which I think is disabled. Enabled allows a more complex VE calculation, and no way to tell if you need it or not, so leave it stock.

[murfie]

Screen Shot 2021-05-30 at 9.22.34 AM.png

Did you mess with this table? If these aren't stock values, then this could be your problem.

Or in the idle area/ the lower RPMs, instead of saying you are able to make 12 psi above baro MAP at 1500-3000 RPMs, make that 0 and still get the benefit of the table where you need it.