Speed Density Only on Z06

[icicleboy]

Has anyone run a speed density only tune on a Z06? I'd like to eliminate the maf altogether, but wasn't sure if there was a known issue when the maf is failed. I did see a max pressure ratio of 0.9 or 1.0 when there is a maf failure and didn't know if that applied.

Thanks in advance for all the help.

[TransAm8723]

I do know that (more of an annoyance than problem) is that cruise control will not work in SD only. Found that out on a few earlier gen5's I did. Any particular reason you want to delete the MAF?

[Higgs Boson]

I have not been able to build boost without the MAF no matter what I set MAF Fail PR Limit to, even overriding the system and putting 5.0.

On a 2014 Stingray it would work fine.

[icicleboy]

Thanks for the reply guys.

Higgs : I figured the exact same thing as I upped the value to 1.0 and saw no difference. Once I moved the maf fail back to 16khz, the throttle became MUCH snappier as PR would easily exceed 1.0 into boost instead of being throttle limited.

The reason for wanting to move to SD only is that Procharger places the maf in the end tank of the intercooler, in a location that sees lots of turbulence. They also only provide a 3" charge pipe with the kit. So to move it means to make a new 4" pipe, etc. I also found that on SD only the car is idling perfectly and is very well behaved in general. With the turbulent maf location with blending on and with the SD well tuned in VVE, it still doesn't idle and transient well as the frequency is all over the place due to erratic flow over the maf card.

Does anyone know if HPT is working on a fix for this issue so we can run SD only on these cars with a P101-P103?

[Higgs Boson]

Thanks for the reply guys.

Higgs : I figured the exact same thing as I upped the value to 1.0 and saw no difference. Once I moved the maf fail back to 16khz, the throttle became MUCH snappier as PR would easily exceed 1.0 into boost instead of being throttle limited.

The reason for wanting to move to SD only is that Procharger places the maf in the end tank of the intercooler, in a location that sees lots of turbulence. They also only provide a 3" charge pipe with the kit. So to move it means to make a new 4" pipe, etc. I also found that on SD only the car is idling perfectly and is very well behaved in general. With the turbulent maf location with blending on and with the SD well tuned in VVE, it still doesn't idle and transient well as the frequency is all over the place due to erratic flow over the maf card.

Does anyone know if HPT is working on a fix for this issue so we can run SD only on these cars with a P101-P103?

I don't think it's for HPT to fix, at least not without a custom OS, which I believe they have stated they are not doing. Pretty sure this is baked into GM's OS.

I would just move the MAF.

[veee8]

Anybody try raising the Maximum Limit Factor under the Dynamic Airflow tab?
Screenshot (23)_LI.jpg

[TransAm8723]

Good eye veee8. I've never personally tried it but it could work. We have a few Procharged C7Z's waiting to be tuned, so I anticipate the same turbulence problems the OP mentioned. Guess we will see, as always.

[Harlech]

I don't guess I see the issue with relocating the MAF to somewhere with less turbulance. My truck and procharger behave well on SD but way better with the MAF enabled.

[Redline MS]

GM heavily relies on both air models to calculate the torque model. More so on the factory boosted cars. Your much better off going with the 4" pipe. The 3" pipe is way off balanced with the airflow mass that the F series blowers produce. NOTE.....it also has a big impact on how the fuel ring calculates rail pressure.....

[GrannySShifting]

So no pure SD Redline?

[andrewzpsu]

The only GenV I have issue going SD is the 2017 ZL1 - goes into a limp mode the moment the MAF fails, and no matter how it is failed. I've been in contact with HPT, but nothing has come of it yet.

I can go Boosted SD on the rest of the GenV without issue.

[Higgs Boson]

post a 2015/2016 LT4 file in SD please.

[Engineer@HPT]

The only GenV I have issue going SD is the 2017 ZL1 - goes into a limp mode the moment the MAF fails, and no matter how it is failed. I've been in contact with HPT, but nothing has come of it yet.

I can go Boosted SD on the rest of the GenV without issue.

Please log the Reduced Engine Power PID when the issue occurs and send that log to support.

[meatbag]

Bump, cant seem to get a 2016 to run in SD with maf failed either.

[GrannySShifting]

Ive been screwing with a 2017 SS doesnt want to cooperate in SD either....