[Evil-Bee-NH]

So when I had my most recent tuning day at my tuners shop we decided to go back to stock and slowly build the entire tune brick by brick this time around. I'll add dyno charts later today. For the record we haven't set any torque management numbers to max yet and have left them at stock settings for now until we eek out every nook and cranny of the current 3.7 beta available tables.

Both my ECM and TCM are unlocked and we have zeroed out slip% tables completely across all 8 gears but haven't done much with shift pressure quite yet.

The tunes are back and forth he'll change one thing and it slaps another thing in the face thus is the challenge of deep-tuning our new totally electronically controlled cars. I'll likely get naysayers for that but how many people have really delved deep into what effects what in our cars while tuning and just done small changes to obvious areas for gains. I can speak all day about tunes done for other people and my thoughts and opinions are as abusive and unfiltered as the pleebs on Facebook ranting about their size issues and we all know i'm as combative as they come when I see bullshit in my own mind, while others take a more silent overly tempered approach and discuss with me privately.

To start my tuner isn't an expert I've said this many times before, he has extensive background in FI DI tuning with Camaros and other GM vehicles Turbo, Supercharged and Nitrous builds. He's tuned a multitude of the new EcoBoost engines from the Focus RS to Rustang as well. What he's seen in the 2.0T Camaro is an amalgamation of shit that effects things not normally affected by certain changes on most other Turbocharged builds. Currently we're using 5th Gear as our testing gear because 6th boost nose dives before maximum speed and 4th is to short my current tune in 4th is 296whp/352wtq and 5th is 276whp/362wtq in 86 degree humid weather after a long 2 hours of dyno and road adjustments. Now my original tune just ECM was 307/329 in 4th but the car would nose dive like the stock tune would and was being hindered by the driver demand and TCM being locked to stock parameters. We've been experimenting with the electronically controlled waste gate and have found a ton of power there being restricted by stock settings. So hopefully this gives someone something to look at.

What we did find when we reloaded the stock settings was Stock PSI was set to 29 PSI. from the factory. That's insanely high and most dyno and read at 18 to 22 PSI this finding and Jason@JacFabs recent YouTube Videos about projects simply confirm the insane amount of boost leakage through the plastic to metal recirculation valve and that GM knows and had compensated for this in their factory tuning. Others should take a look and share what they find. When a metal to metal solution comes around with a better seal setting to 25 PSI would probably be a safe area. But we'll test and dyno and share anything and everything we find with you.



Thread Disclaimer:

I've been told by some that my tuners not that impressive but his general numbers are right where the notable companies are and better, so shit talking is just that shit talking we could do that all day instead i'm looking to take a constructive approach and maybe ignite a fire under people to share their findings and information. Thus far only Jason@JacFab has done this. I'm not looking to put anyone or any company on blast but we simply don't share enough information for such a reclusive small community and it hurts our progress immensely so let's maybe start something good with this thread.

[Evil-Bee-NH]

That new OS is gonna be interesting i wonder why they did that. I know they did it when they changed from LLT to LFX in the 5th Gens but there's no engine change.

I'm happy with my tuner we did a baseline pull way back when i was still stock. So we've been able to see what's changed since i put on bolt-ons and then tuned. As far as GM and the factory max boost limit they've done weirder things. But i agree so many things mess with readings on a dyno it's insane.

[geoffchad]

I think a lot of people forget that selecting transmission gear ratios when designing a car is like a 7 dimensional graph to find where the gears should be.

GM has teams of engineers doing these calculations and then teams of engineers coming up with 'calibrations' after extensive testing on load cells. The number of hours that go into the factory 'calibration' on the engine and transmission is staggering - and these guys work with DI and boosted engines every day, often the same engine family for months or even years.

Any good tuner should say that tuning is a bit of an art and there's no one perfect way to do it, and tuning an engine to max power makes compromises in places for a daily driver you don't want to do.

...

If you can get a manual transmission car to your tuner I think that would help to isolate the engine from the transmission's own whims - while the resulting tune would be different between the cars, it might help to explain some of the anomalies?

On your dyno numbers (I've reverse calculated RPM):
296whp/352wtq @ 4416rpm? (new)
307whp/329wtq @ 4901rpm? (old)

Without seeing the graphs, I remember how many ATS's were falling flat in high RPM just due to the limits of the stock turbo and supporting hardware, and from your graphs you've seriously shifted power down into the usable range, I'm curious where both tunes (all physical parts being equal) fell on their face at top end and how quickly - I wonder what temperatures were like between them regardless as to what the transmission was doing - its possible that the exhaust and cylinder temperatures were different enough to cause some variation across a pull.

That or there's also the fact that depending on how much boost the engine is seeing could impact how much is being bled back from the factory bypass valve - the amount it "leaks" may not be a linear relationship with compressor discharge pressure after all.

I am really genuinely horrified how much airflow is just spun in circles thanks to the plastic valve.

[ChicagoTommy]

Originally Posted by geoffchad

I think a lot of people forget that selecting transmission gear ratios when designing a car is like a 7 dimensional graph to find where the gears should be.

GM has teams of engineers doing these calculations and then teams of engineers coming up with 'calibrations' after extensive testing on load cells. The number of hours that go into the factory 'calibration' on the engine and transmission is staggering - and these guys work with DI and boosted engines every day, often the same engine family for months or even years.

Any good tuner should say that tuning is a bit of an art and there's no one perfect way to do it, and tuning an engine to max power makes compromises in places for a daily driver you don't want to do.

...

If you can get a manual transmission car to your tuner I think that would help to isolate the engine from the transmission's own whims - while the resulting tune would be different between the cars, it might help to explain some of the anomalies?

On your dyno numbers (I've reverse calculated RPM):
296whp/352wtq @ 4416rpm? (new)
307whp/329wtq @ 4901rpm? (old)

Without seeing the graphs, I remember how many ATS's were falling flat in high RPM just due to the limits of the stock turbo and supporting hardware, and from your graphs you've seriously shifted power down into the usable range, I'm curious where both tunes (all physical parts being equal) fell on their face at top end and how quickly - I wonder what temperatures were like between them regardless as to what the transmission was doing - its possible that the exhaust and cylinder temperatures were different enough to cause some variation across a pull.

That or there's also the fact that depending on how much boost the engine is seeing could impact how much is being bled back from the factory bypass valve - the amount it "leaks" may not be a linear relationship with compressor discharge pressure after all.

I am really genuinely horrified how much airflow is just spun in circles thanks to the plastic valve.

You, Sir, get a gold star. This is a VERY informative post and probably the most intelligent I've seen around here in a while.





Evilbee, you sure your tuner didn't mess with driver demand tables? That is usually the first hurdle people run into. Once you exceed calculated torque, the ECU will start closing the throttle blade. Anyone that has tuned more than 2 of these cars should know that. I don't generally post that info, as I don't wish to enrich tuners with my knowledge, but you've genuinely piqued my curiosity. That was the biggest hole in the first iteration of the RPM tunes I saw... I'd bet a dollar that is why you feel the car falling off in upper RPM. Do you have HPT? Are you logging throttle angle %? If you don't have HPT, or some other way to datalog your daily driving, you definitely should. You can not possibly hit all the necessary cells on a dyno. It takes HOURS of driving in all kinds of conditions. As Geoff said, GM's driveline engineer spend THOUSANDS of hours building the stock tune and it is so designed to handle just about any condition from -37 degrees outside, to 130 degrees outside. That's a lot of variables that can only be discovered by driving and datalogging constantly.

[Jason@JacFab]

Originally Posted by geoffchad

That or there's also the fact that depending on how much boost the engine is seeing could impact how much is being bled back from the factory bypass valve - the amount it "leaks" may not be a linear relationship with compressor discharge pressure after all.

I am really genuinely horrified how much airflow is just spun in circles thanks to the plastic valve.

True it may not be a linear leak, although, the higher the "boost" I put to it on the test fixture the greater the leak... There may be a point of where it leaks a certain amount and holds that amount and the leak does not increase, but hard to say.

Originally Posted by ChicagoTommy

Evilbee, you sure your tuner didn't mess with driver demand tables?

He mentioned his tuner was having "issues with the driver demand tables", and said something along the lines of "It's a picky b!7@#" to me. I offered to look at the driver demand tables, told him to send me a screen shot, but never got anything.

What he describes to me is throttle closing, I'm guessing due to driver demand tables not being where they need to be...

I can attest that at a certain point, in certain gears (my issue was in 5th gear), that something in the tune wants to be changed, as out of nowhere, as the power continued to increase, other tables will need to be massaged. Toward the end there, I developed a problem where the throttle would close on me in 5th gear only. We had not quite figured it out when my piston broke.

I can also say that there are two tables that are needed to be messed with to cure cars starting to fall on their face over 100mph that HP Tuners doesn't even currently have access to, or at least didn't as of a couple weeks ago, that were only accessible using other tuning software.

I will have my car back from the dealer, getting all 4 pistons replaced under warranty this week, then we will be back at it!


Regarding the leaky valve. This week, we will be testing prototype #4 of the replacement recirc valve that (fingers crossed) does not leak. I know its been a long wait, but it will be WELL WORTH THE WAIT. We've been working on a lot of things in the background, just not sharing as much info as I have in the past.

[Evil-Bee-NH]

@ChicagoTommy - No i don't have HPTuners yet. I really want to get it but i have other priorities in life right now. Plus I'll likely get 17s and DRs before i get hptuners I'm having to much fun at the track.

@Jason@JacFab - Ya i dunno why he didn't share anything it's been a long process and he's finally getting things dialed in with this last tune. Problem with dynos is they are a measuring tool and no one measuring tool, enviroment or circumstance is the same. Funny enough i haven't had the throttle controller out of the stock setting in over a month but it still shows the throttle position % on it I'll try videoing a 5th gear pull sometime.

[Jason@JacFab]

Originally Posted by Evil-Bee-NH

@Jason@JacFab - Ya i dunno why he didn't share anything it's been a long process and he's finally getting things dialed in with this last tune. Problem with dynos is they are a measuring tool and no one measuring tool, enviroment or circumstance is the same. Funny enough i haven't had the throttle controller out of the stock setting in over a month but it still shows the throttle position % on it I'll try videoing a 5th gear pull sometime.

I'm not 100% certain, but I believe the throttle controller displays the throttle PEDAL position, and not the throttle BLADE position in the throttle body. At least thats what I remember the last time I played with one a few years ago. I'm pretty sure the throttle controller has no way of knowing what the throttle blade position is. So the video wouldn't do much good. You need some kind of logging software *cough*justgobuyhptunersalready*cough* to log the throttle blade position.

[Evil-Bee-NH]

Originally Posted by Jason@JacFab

I'm not 100% certain, but I believe the throttle controller displays the throttle PEDAL position, and not the throttle BLADE position in the throttle body. At least thats what I remember the last time I played with one a few years ago. I'm pretty sure the throttle controller has no way of knowing what the throttle blade position is. So the video wouldn't do much good. You need some kind of logging software *cough*justgobuyhptunersalready*cough* to log the throttle blade position.

Ya no HPTuners for awhile i had to cancel going to Camarofest 8 this year as well. Real Life issues and such... Still going drag racing on my local tracks two street nights though.