2017 C7 Bolt-ons - Questions on TQ, driver demand, maxed airflow

[99z28u_up]

I will start by saying I am a hack tuner at best. I have lots to learn and am trying to ask questions in that effort.


I have a 2017 C7 Stingray. Mods are MSD Intake, Soler 103TB, AFE CAI, 2" TSP longtubes and Xpipe, AWE Race Ed Catback, and Nitrous (We'll ccircle back to this), 2016 TCM (Custom Transmission tune). I think I have maxed out the NA efforts of the current setup. I am seeing MAP at 98KPA at WOT, which leads me to believe that there is lil restriction on the intake side. I am seeing max MAF readings of 51 LB/MIN at WOT, which I think is pretty good.


My first question is, Can MAF increases be used to gage if the car is making more power?

Is anyone seeing LB/MIN MAF readings in excess of 51 lb/min?

Can VVT be used to increase airflow and make more HP? If so, how?

Can someone tell me what the PID "Driver Demand Engine Torque (SAE)" represents. Its a percentage and can be seen in the attached log.

Are SOI adjustments required when adjusting VVT advance/retard?

[99z28u_up]

Not a single reply. Either I should already know this or it's an illuminati secret and I am not allowed access to this information. Which one is it because there are some very smart people on this forum.

[FastV]

Not a single reply. Either I should already know this or it's an illuminati secret and I am not allowed access to this information. Which one is it because there are some very smart people on this forum.

So Ive only been tuning for roughly 3 years and I actually learned on a Gen 5 platform. Completely ass backwards, but it was on my own shit so.... Here is what I can tell you. You can roughly judge power by air flow. The engine is an air pump right, so more air more fuel more power. 51 lbs/min is roughly 510 hp crank. The VVT Retard in the tune is pretty good from factory, but maybe there is something to be gained down low? SOI is really only adjusted when adding a Cam. From what I can tell the factory SOI is in line with the factory cam specs. I've seen Driver Demand Axle tq but not engine Tq so I can't answer that question... This just my 2 cents. There are way smarter people on here than me to answer these questions too.

Good luck

[FastV]

So Ive only been tuning for roughly 3 years and I actually learned on a Gen 5 platform. Completely ass backwards, but it was on my own shit so.... Here is what I can tell you. You can roughly judge power by air flow. The engine is an air pump right, so more air more fuel more power. 51 lbs/min is roughly 510 hp crank. The VVT Retard in the tune is pretty good from factory, but maybe there is something to be gained down low? SOI is really only adjusted when adding a Cam. From what I can tell the factory SOI is in line with the factory cam specs. I've seen Driver Demand Axle tq but not engine Tq so I can't answer that question... This just my 2 cents. There are way smarter people on here than me to answer these questions too.

Good luck

So, I just looked at your log and tune. You have a ton of knock upstairs, if that true knock. Timing doesn't seem excessive though especially in the cold weather you are driving in. You have your low octane and your high-octane table copied the same. If it is true Knock, you have no protection to learn down to the low octane table. I would change that Immediately until you confirm if its real knock or not. Fuel seems spot on, but maybe richen it up a tad to 12.8 instead of 13.0? Just another protection adder if you are knocking. May or may not add a few ponies depending on what the engine wants.

Kind Regards,
Ryan

[TriPinTaZ]

I typically avoid threads like this because what you're asking is such a small piece of the puzzle. I have been tuning since the late 90s and I had to deal with a steep learning curve on the Gen V platform. But more around how things fit together and the torque based stuff. I would recommend you watch youtube videos and search this forum and read all you can. There is a ton of information out there. And its impossible to give someone a run down of the basics because its not basic. I would guess that is why most experienced guys avoid threads like this. But I will try to answer some of your questions.

Since you changed your intake, your MAF reading has been skewed. You cannot compare it to OEM for an accurate power increase. You can convert airmass into torque to measure approximate gains, but your delta is no longer accurate because of the AEM intake.

51lb hour? sure I've seen more, but changing the intake can skew the MAF readings. Changing the MAF curve can also skew these readings. I wouldn't get hung up on trying to use airmass to calculate your HP or torque.

VVT- I can be moved around but there is little to be had if anything. I used to move the cam a little in my tunes, but I don't anymore for peak HP. I do however reduce is movement down load for drive-ability.

Driver Demand Engine Torque is what the ECU thinks you're asking for from the gas pedal in regards to torque. Some cars are torque at the flywheel and some cars are torque at the rear axle after it has been multiplied by the transmission. Usually the torque at fly wheel is for manuals and the latter for autos.

No need to adjust SOI unless you change the cam.

[99z28u_up]

I typically avoid threads like this because what you're asking is such a small piece of the puzzle. I have been tuning since the late 90s and I had to deal with a steep learning curve on the Gen V platform. But more around how things fit together and the torque based stuff. I would recommend you watch youtube videos and search this forum and read all you can. There is a ton of information out there. And its impossible to give someone a run down of the basics because its not basic. I would guess that is why most experienced guys avoid threads like this. But I will try to answer some of your questions.

Since you changed your intake, your MAF reading has been skewed. You cannot compare it to OEM for an accurate power increase. You can convert airmass into torque to measure approximate gains, but your delta is no longer accurate because of the AEM intake.

51lb hour? sure I've seen more, but changing the intake can skew the MAF readings. Changing the MAF curve can also skew these readings. I wouldn't get hung up on trying to use airmass to calculate your HP or torque.

VVT- I can be moved around but there is little to be had if anything. I used to move the cam a little in my tunes, but I don't anymore for peak HP. I do however reduce is movement down load for drive-ability.

Driver Demand Engine Torque is what the ECU thinks you're asking for from the gas pedal in regards to torque. Some cars are torque at the flywheel and some cars are torque at the rear axle after it has been multiplied by the transmission. Usually the torque at fly wheel is for manuals and the latter for autos.

No need to adjust SOI unless you change the cam.

Thank you for answering the questions.

[99z28u_up]

Yeah, I dialed back the timing and the knock went away. We only have 91 Octane here where I live in California. Thank you for the input.