Torq Coefficients effecting Exhaust Valves Interesting Correlation

[Redline MS]

Was calibrating at 2015 Z with manual trans the other day with bolt on's. I was modifying the Torque Coefficient Models for Airmass Based A-D to resolve a throttle issue) which solved the issue, but it caused two other issues. The car had a Corsa exhaust with the exhaust valves deleted when it came in. After calibration it started getting a code for the exhaust valves (which it didn't have prior) ....then once off the rollers it would trip to REP at low rpm high load tip in....I chased it around for a bit and decided to return the values back to stock....both issues went away. This confirms that the valves for sure operate off a torque model somewhere. The REP must be from a limit not matching the TC change but I couldn't find which one was clipping it...anyone seen this effect...I might of just needed less of a change by these coefficients are a crap chute since the values are just that..

[Higgs Boson]

Yes.

Interesting that I also just discovered this yesterday. It's been a long time since my C7 was stock, and I am pretty sure I started modifying my torque tables right off the bat. I always found it peculiar that in Touring Mode my exhaust valve would stay closed under WOT and snap open around max VE RPMs.

Never got a REP or code from it but I finally had a chance to dial in my meth injection yesterday and on the first hit, it pulled nicely and then around 4000 RPMs it popped like a charge tube came off and REP message with CEL. Maybe too much meth? Clear all the codes, turn it down, go again, boom same thing.

Code was P0324 Knock Control System Error and P16F3 (not sure what that is).

So with lots of meth and very little meth it was doing it so I disabled the codes and the only thing that occurred to me to do was put the torque tables back to stock. I put them all back to stock but the only one that I had recently tested changes with is the EQ Ratio table so this might be the one.... The car pulled clean but started to close the throttle around 5k so I stuck it back in the garage so I could play with my Mustang and deal with this later.

With that said, the car drives way better on stock torque tables not to mention the NPP works a lot better as well. I am leaving them stock from now on and will only modify the cells necessary to retain 100% throttle, which may be only the DD table....

[Redline MS]

That's exactly the code I was getting P16F3....I just looked it up and its

Control Module Redundant Memory Performance. God only knows what this means...no other explanation from GM.

I was messing with them as they instantly solved a throttle intervention at 3500-4800 rpm that every manual trans car with a boost increase does. Those tables nailed it so there is some kind of limit in the manual ZO6 that needs to be raised. The modified torque table did fix that but somewhere another model wasn't happy... I had to get car back to customer but I'm going to finish off where I left off with this on the next car....Most certainly a correlation for sure.

[Road]

That's exactly the code I was getting P16F3

Try going the opposite way with the coefficients then make changes to peak/demand to keep throttle blade open.

Code was P0324 Knock Control System Error

Brought in too much air in the lower rpm range causing timing from higher scale to be used in the lower rpm range. Adjust both timing tables so that the ecm doesn't hit a wall.

[Redline MS]

That's exactly the code I was getting P16F3

Try going the opposite way with the coefficients then make changes to peak/demand to keep throttle blade open.

Code was P0324 Knock Control System Error

Brought in too much air in the lower rpm range causing timing from higher scale to be used in the lower rpm range. Adjust both timing tables so that the ecm doesn't hit a wall.

So you guys both at Knock Error codes I never got that to trip..... I was thrilled it resolved that low rpm throttle control but this has to be another limit issue. We need a torque model tool.......like GM has....

[Higgs Boson]

Code was P0324 Knock Control System Error

Brought in too much air in the lower rpm range causing timing from higher scale to be used in the lower rpm range. Adjust both timing tables so that the ecm doesn't hit a wall.

Not sure what you mean by higher scale.....my High and Low Octane tables are identical, never had this code until I hit the meth and right on the first try. have not had this on other cars I have tuned with/without meth either.

[Road]

Not sure what you mean by higher scale.....my High and Low Octane tables are identical, never had this code until I hit the meth and right on the first try. have not had this on other cars I have tuned with/without meth either.

I have had that code whenever it detects knock and it hits a wall and there is no way to pull timing then you get knock module performance issues. You need to use both tables on torque bias ecm's. At least that has been my experience.

[Higgs Boson]

I have had that code whenever it detects knock and it hits a wall and there is no way to pull timing then you get knock module performance issues. You need to use both tables on torque bias ecm's. At least that has been my experience.

There is no knock, but it is trying to pull timing.

This ECM will pull timing if it thinks it needs the room to spray before spark.

I guess it uses the same system (or logic system or whatever) to pull timing from knock or power reduction or for whatever purpose.

That's why I don't think it's the knock sensors picking up false knock, it's the ECM pulling it for the torque model.

The reason it can't pull timing is because I disabled it on my car until I get the wot fuel/meth maf curve tuned and it doesn't feel the need to pull it out anymore. I can't tune it when it brings spark down to 0 or -3....

[Sam88gta1]

I had that same code and exhaust valve problem on the 16 A8 Z with the F1R we build last month. I managed to fix the problem 1 day before it left on the transport back to California. I never did gain back total control of the exhaust valves but at least the code stopped appearing and the valves opened under WOT.
I had to put the Engine torque coeff EQ ratio table back to stock and only modify the a-d tables. The combination of the two being lowered caused the code. I lost some sleep over that one.

Ive found that a 8-10% reduction to the a-d tables fixes the boost drop that you experienced without any negative effect.