Look the point of this thread was to show that an extremely reputable person who knows more about the computer on our cars than anyone on this forum is saying learn down will never go away. The computer will always try to hit that set air flow regardless of modifications. So if the airflow is set higher than the stock components can achieve...then aftermarket parts will help it to achieve that number. Who knows how high gm set their airflow for the stage kit? Either way...at some point the car WILL try to learn down to that airflow if the components you strap to the car can achieve a higher airflow. PM vince and ask yourself.

So, based on the way the computer works on this car with everything based on airflow. Just setting the airflow to “unlimited” or infinity would be the only real way of removing the learn down feature. And who knows…maybe GM did set it to unlimited or something…although that I doubt because this thing would be a monster because then no matter what you do to it, it would pretty much automatically tune itself other than fueling..it will adjust cam timing and turbo pressure. Bring on the GT40r!! But I would highly doubt that. Maybe GM set it ridiculously high and that’s why the torque numbers are so high (+80) and the hp numbers aren’t (only +30). Perhaps that is just what the stock components max out at for the airflow and they just don’t have the abilities for extreme top end. Or maybe that’s just high hopes and GM didn’t set the airflow that high. Either way…”learn down” will stay with this car unless airflow = infinity.

 

"it goes to eleven"

 

For the stock number they rate engines at the crank (net HP) per SAE J2723 using the method detailed in SAE J1349. The engines have to be within 2% of the rated HP. The equipment for torque must have a margin of error less than 0.5%.

 

Driveline lose is only about 10% on a manual transmission fwd car. 15% on a rwd manual car and 20% on a awd manual car. Losses are approximate!!! a 240 whp fwd manual car is approx 264 engine HP. Some dynos are happier than others and some cars make a few HP more than others so unless someone does a baseline run and than a stage tune run there is no trusting the numbers really.

 

we wont know until there is some real testing done on the new sensor positions as to whether it is beneficial or not to have the stage kit + additional tuning done. It will be interesting to see what companies like trifecta or hahn will be able to do with the new sensor positions.

 

ADM Performance made 50 whp over the stage tune results on their HHR after tweaking the tune with HP tuners. . It made approx 240 whp stock. Stage tune only 270 whp Stage tune plus IC, DP. Catback, stock intake. 288 whp. They made 338 whp and 395 wrtq with some tweaks to the stage tune.

 

Hm, i thought drivetrain loss was more than that.. That makes more sense though.

 

Jesus Titty F@#&ing Christ that's a lot of torque. new clutch FTW!!

 

Appoximate numbers. My 400 Hp GTO was 330 whp Stock RWD auto=20% loss. FWD auto 15% loss. AWD auto 25% loss. Depends on the car but those numbers come out real close as long as SAE dyno numbers are used.

 

I'm not sure why people would expect the "learn down" to be disabled. The ECM targets a specific airflow as Terminator was pointing out on the 1st page. Adding exhaust mods just makes this airflow happen at a lower boost level. Don't think of it as a "learn down", think of it as a target airflow. Without changing the desired airflow, you can not make huge HP gains. There are still gains to be had based on improved efficiency, but no airflow gains to be had without altering your boost control or changing your desired air mass tables. When you raise the desired air mass tables higher than the stock setup can achieve, then there are better gains to be had by adding airflow mods.

With our S256 ET turbo, we were seeing 28-30 psi on full computer control after driving the car for a while with the air mass tables cranked up.

 

QFT.
I hate the misnomer "learn down feature" I wish everyone would stop using it as I have posted those exact words about the desired air loads in 10 or more threads now. Knowledge is supposed to rub off right?

 

sub'd

 

That's why "learn down" is in quotes...it's not really something that's true...it's just what it's known as and an easy reference point. After having read Vince's description...I don't know that the gm stage kit is even worth it if you're aiming for 300 at the wheels.

 

Damn I really want it to be next Saturday to find out. This is killing me lol

 

There is not any learn down with the stage kit. When the stage kit is installed and you install your new fresh air intake or exhaust that gains you 20 HP, It will stay and not be learned out!

The person that posted has it wrong about how the calibrations function.

Also, the new air cleaner/intake pipe that he says was having problems... That is due to a poorly placed air flow meter in the intake, not any learn down feature.
__________________
I am a GM Engineer, These Opinions are my own





thats from the same lnf forfums

 

This is what Bill Duncan wrote me about the stage kit. He is ne of the engineers behind it

The Learn Down feature is turned off with the stage kits. There is still a set or target torque. you can see this from the Solstice GXP manual torque vs the HHR SS torque. Now the learn down feature on the production calibrations learns out any modification and set the engine back to it's original Torque curve. On the Stage Kits since it is turned off it will allow modifications to exceed the "target" torque and NOT learn them back out. I hope that explains it. If not ask another question and I will try and explain further.

Bill

 

Isn't GM changing the operating system? Why would they want to do that? What would be the benefit? If the "learn down" is permanent and can't be removed what are the aftermarket tuners changing to get around the limitations posed by the stock T/MAP's?

Just curious.

 

Look at my post above yours. The learn down is gone with the stage kit

 

Actually I was directing my questions to those on this thread that disagree with US saying the learn down stays. Maybe getting them to think a little harder about what they are saying. I am agreeing with you. Sorry about the confusion.

 

Oh its all good Bro lol

 

Now THAT I understood I'll await more dyno results B4 making a decision on a tune. Can the Trifecta tune be "tweaked" to maximize other mods. This would seem to give aftermarket tunes an advantage over GM's-can anyone clarify?

 

Aftermarket tunes are ALWAYS FTW over a factory canned tune. ALWAYS.

 

Look at the way this car regulates power by limiting boost. Some peoples cars pull 18-20 PSI at WOT. Mine pulls 15 PSI at WOT. I have read people pulling as low as 10 PSI. In any case the target of 260 ft/lbs is reached.

The stage kit removes the down regulation of boost that is modulated by the waste gate.
It promises to keep boost at 22-23 PSI.

Therefore, if one is to add modifications to the car (i.e. intake and exhaust), thus increasing volumetric efficiency, the power output will increase.

 

i have pulled as low as 8 psi here in louisiana wen it was cold!

 

This is because the factory has to meet emissions requirements to sell it over-the-counter, period.

Aftermarket can sell as an off-road-use-only, but if you have to get your car checked annually then you could have a problem.