[White_1LE]

I'll try to keep this concise, but it is a head scratcher for me.

I have a 19 SS 1LE I bought new in April. I entered a competition at a car show and part of it was a dyno. It made 342 RWHP on a DynoJet. They did not have a WBO2 on it. It was a fast paced event so the dyno operator didn't have time to mess with it or talk to me, but said he was surprised how low it was.

I was expecting at least 380, maybe more. I chalked it up to them not knowing what they were doing or maybe their mobile dyno was F'd. But still, a glimmer of doubt was there.

So I took it to another local shop (TPIS) and had it run again and it still made ~340, but this time we had AFR, and it is pig rich at ~10.5:1 throughout the pull. It is choking itself out and making peak power at around 5k RPM.

No MIL/CEL, poked around looking at MAF readings and temp sensors and all seems correct. But LT Fuel Trim is -17 to -20 on both banks.

The car has the dealer installed GMPP CAI, so I swapped that out to the stock setup when I got home to see if the LT FTs would be better, but no dice, still in the negative upper teens driving around and holding at 2k RPM sitting in the driveway (no load). Double checked all connections, cleaned MAF, no change.

I really don't want to take it to a dealer. I know what kind of gamble that is to find a competent tech and advisor (I was a tech many moons ago). But I feel like maybe the calibration is bad in this car? It is acting like the MAF scaler tables are off, but come on... it literally has 3k miles. How? Does the GMPP dealer installed CAI come with a calibration flash?

Appreciate any ideas.

[JK001]

What mode was your car in? S, Track, etc do not allow for all available power. Double click TC button in either the above to access all power. See the PTM demystified sticky at the top of the forum section for complete information.

[White_1LE]

Sport, Competition Mode

[White_1LE]

At TPIS we had more time and played with settings a bit.

In Sport mode with TCS off it made 306 RWHP. In Sport mode, Competition mode, it made 335 RWHP. Both are 10.2-10.5:1 AFR and power flattens out at ~5100 RPM. We also yanked the air filter for a pull but it made no difference at all.

Do these cars have problems with the TB blade not opening all the way but telling the PCM all is well? It shows 100% throttle when I floor it on the scantool.

[appleman22]

subscribing for updates! good luck

[TJay74]

Originally Posted by White_1LE

Sport, Competition Mode

The PTM modes should have zero affect on the power level unless you are the wet or snow modes. Tour, Sport and Race will all have the same power, just changes how the power is put down to the ground on the ramp in rate for the TB opening.

At 100% WOT on a scan tool the TB will report 83% open, that is normal from what I have seen on scans.

Do you know if the dyno operator turned off the traction control before the run?

[ChevyRules]

The GMPP CAI should come with a tune I believe that the dealer should have done. Unless I am confusing it with something else.

[3.8TransAM]

If everything else is normal and your long term fuel trims are what you say they are, most obvious culprit tends to be a MAF. Seen this a few times in my tech days.

[White_1LE]

Originally Posted by TJay74

The PTM modes should have zero affect on the power level unless you are the wet or snow modes. Tour, Sport and Race will all have the same power, just changes how the power is put down to the ground on the ramp in rate for the TB opening.

At 100% WOT on a scan tool the TB will report 83% open, that is normal from what I have seen on scans.

Do you know if the dyno operator turned off the traction control before the run?

Yes, on the runs at TPIS. I cannot speak for the other dyno, but he said he had it in Track mode with "everything off". I am not sure what that means, and I am not sure how well he knows these cars, but that is why I wanted to make some pulls on a different dyno in a more relaxed environment.

At TPIS, TCS was always off. Just ran once in regular Sport with TCS off, then again in Sport with TCS and Stabilitrak off and in Competition Mode. Made a few pulls in each mode and things were consistent to what I stated in the first post for power and AFR.

When I mashed it to the floor in neutral in the driveway, it read 100% throttle on the Snapon scantool I have.

I did read the "PTM demystified sticky" thread, and I have been using Comp Mode in Sport for pretty much everything except AutoX.

[White_1LE]

Originally Posted by ChevyRules

The GMPP CAI should come with a tune I believe that the dealer should have done. Unless I am confusing it with something else.

That would make sense to me, except when I put the stock system back on, it still had low LT fuel trims.

[White_1LE]

Originally Posted by 3.8TransAM

If everything else is normal and your long term fuel trims are what you say they are, most obvious culprit tends to be a MAF. Seen this a few times in my tech days.

Yeah, I am thinking the same. Outside of a possible calibration issue, but that would be really odd.

I wish I had a known good MAF I could toss in and try out. I bought this thing in part so I DON'T have to tinker with the damn thing all the time. I have an 87 GTA that gets far more of my time and energy than it should for that stuff...lol.

[Whitespeed]

Sounds very similar to what member TIM M went through. Power way down and running rich. Check out post #75 in this thread for dyno results...



https://www.camaro6.com/forums/showt...=542089&page=6


Turned out to be an incorrect tune installed by dealer when the cold air intake was installed. See post #108


https://www.camaro6.com/forums/showt...=542089&page=8


Nigel

[Boost Creep]

Originally Posted by Whitespeed

Sounds very similar to what member TIM M went through. Power way down and running rich. Check out post #75 in this thread for dyno results...



https://www.camaro6.com/forums/showt...=542089&page=6


Turned out to be an incorrect tune installed by dealer when the cold air intake was installed. See post #108


https://www.camaro6.com/forums/showt...=542089&page=8


Nigel

This.

Sounds like the same thing he went through.

[yotaman96]

Yep, sounds like the exact same issue as stated above.