[NA18CamaroSS]

Having an interesting issue with my 2018 Camaro SS 1LE. Had the car tuned a couple of weeks ago and I have been sorting out a few issues. The part throttle was a little wonky and playing with the throttle tables smoothed out that problem. I am seeing a strange problem at full throttle. The PCM is pulling 10-15 degrees at around 6,000 RPM at full throttle. It's not knock retard. No matter if I am running 21 degrees or 25 degrees, the same thing occurs. The only mods on the car are a Soler Performance throttle body, a Green filter drop in air filter, and a flex fuel kit. The E85 that I am getting at the local pumps runs about 78-80% ethanol. I have attached a screen shot of the datalog right before the problem occurs, and one of the actual issue occurring. Ideas?

[6spdhyperblue]

Are you logging all the torque pids?

[Juiced1]

That's a torque table issue. It'll pull timing if your max torque is over peak torque or if you eng torque is over max torque. It's not very fun to work with but I'd take it back to your tuner. They most likely didn't dial in your VE tables

[NA18CamaroSS]

Thanks for the input. The torque limits were moved up by 25%. Not sure which torque PIDs would be helpful in diagnosing this issue. Could you be more specific?

[NA18CamaroSS]

I finally figured it out. For some reason the PCM is seeing more than the estimated max value for the MAP sensor. Upping the value eliminated the problem.

[KingLT1]

you shouldn't be over 100 unless you are running boost.

[NA18CamaroSS]

The stock value for estimated MAP maximum is 105 kPa. Datalogs show that the maximum logged MAP value is 100 kPa. Not sure why the PCM is reacting to the MAP value the way it is, but moving the estimated MAP maximum up to 135 kPa eliminated the issue. I have attached a screen shot of a datalog I just pulled tonight, with a nice straight timing curve-no timing being pulled at 6k RPM.

[floridanick]

this is pretty interesting. I would like to hear more about what the values should be and how/why you are maxing out if you are n/a?

[TJay74]

To really be able to see what is pulling any timing you need to log all of the timing systems so you can see what is pulling the timing.

Torque management timing
Timing advance
PE timing
KR timing
Flex timing
Coolant timing
IAT timing

I think there is something like 5-8 timing PIDs that need to be logged so you can see what is pulling the timing. Glad you found, hope that helps out for the future logs.

[Z0Tex]

Originally Posted by B19 Coupe

The stock value for estimated MAP maximum is 105 kPa. Datalogs show that the maximum logged MAP value is 100 kPa. Not sure why the PCM is reacting to the MAP value the way it is, but moving the estimated MAP maximum up to 135 kPa eliminated the issue. I have attached a screen shot of a datalog I just pulled tonight, with a nice straight timing curve-no timing being pulled at 6k RPM.

I believe I'm having the same problem as you: timing dip at 5800 rpm and then back up to normal at 5900ish at WOT. Do you, or does anyone, know where this MAP Maximum value would be found in HPTuners?

[Z0Tex]

Bump.

[floridanick]

Zero out your Static knock table.

[wookwook]

If your graphing, check the HZ peak, and look up in the limit table, 13300hz maybe? It may be MAF HighVoltage Fail. Its a suggested remedy for boosted tuning limits. I don't have the path in front of me but should be easy to located under Air menu. HPT.

[Slowhawk]

I see your not logging actual torque 1+2. Those will show torque drop in that area.
Going to the torque model tables and adjusting airflow would get rid of it too.