I've had my Turbo Upgrade kit installed for about 2 weeks now and it is highly recommended. On the Cobalt it is supposed to make about 280 HP with 320 ft lbs of torque according to GMPP. I don't know if this is measured at the wheel or if this is at the crank, but the seat of the pants feel tells me that the motor is putting out a lot more power and IT IS COVERED UNDER THE FACTORY WARRANTY. Before the tune, it would chirp the tires in second. Now I have to back off slightly to get it to hook up in first, it'll spin the tires in second and third before hooking up and accelerating hard. Boost guage on the A-pillar used to register 15 psi at max boost, now it peaks out at 23 psi. When the weather warms, I need to take it to the track to see what it'll really do, but my guess it that it will be somewhere in the mid to low 13's with the stock Conti's.
Contrary to other uninformed sources, the learn down feature has been removed with the new tune, so in the near future, I'll be installing the down pipe, cat back, cold air intake and charge air cooler (intercooler) with plumbing from Hahn Racecraft and be able to get the full benefit of these upgrades. I also have my eyes on an aluminum flywheel/stage 3 clutch and pressure plate and the bolt on turbo upgrade from Hahn. This is my rainy day/cold weather driver (I normally ride sport touring bikes) , so I don't want anything too radical that will make it marginally drivable, require race gas or bring the gas mileage down to 6 MPG. BTW, if I keep my foot out of it, my mileage has gone up to around 26 or so MPG on a 20 mile mixed city highway commute, a 1 MPG improvement over stock. Driving it hard like you're supposed nets between 22-23 MPG.

 

Go team, I installed all of those upgrades your talking about and lost about 10tq, 5hp. Still needs a tune to benefit from any upgrades. It even has some kind of overspool protection that seems to have slowed my tq curve after the exhaust was installed.

 

Do you have proof of this? The only way to know for sure would be to have a dyno run stock and then another dyno run after all of the bolt-ons and then a third dyno run about 1000miles after the bolt-ons all ons with very similar weather.

 

read it for yourself. Go down to the Cobalt SS section.

The simple changes I am talking about (ie. intake, cat-back, intercooler) only remove restrictions to air in-flow and out-flow. They don't mess with the oxygen or MAF sensors in any way. Engines are not that mysterious if you just think about them as air pumps. Move air in, mix with fuel, fire and move air out. So I think it will work. If it needs a little tweaking to adjust the fuel mixture, so be it. I'm not going to worry about gaining a 1/10th of a second at the strip in my cobalt. That isn't why I bought it. I just wanted something that was fun and moderately fast whenever I take the cage to work. If I want to go fast in a straight line or around curves, I'll just hop on my bike. If I really want to go fast at the strip, I'll buy a stretched out Busa and run high 9's all day long out of the box.


http://http://www.gmpartshouse.com/p...grade-kit.html

 

Very cool. I've been thinking of getting this done too.

 

The intake will skew the maf a tad bit. So it is indeed affected. Air pump, yes, very simple. Cobalt SS with more sensors and solenoids then a.. well.. im not sure, more then anything i've seen before. I miss OBI cars.

An example is if you block off the vacuum on the solenoid or whatever that goes to the bov... which shouldn't change anything... especially just blocked, the sensor reads it and DISABLES boost...from a blocked vacuum from a bov.. These cars are ridiculous.

 

nice to know. im eager to try out the good old butt dyno.

 

I've gotten 271 whp on the dyno. The first two was 255hp and 261hp. It was kind of a bad day to do a dyno run on a cold day about the mid 30's. My tires do chirp in 2nd gear, if the tires aren't fully warmed up, plus the engine needs more time to warm up due to weather. I was pushing 17 psi, but on a warm day around 60's or higher, I was able to push 20-23 psi.

 

u still have learn down, that sucks.

 

ya GMS1 tune removed learn down... read the GM statement about the kit

 

I don't have the "damn" down learn enabled. It was cold damn weather, I had a SRT-4 before and faced the same thing before the learn down feature was ever around. My boost max is 10 psi on that car, and on a cold day I get 7 to 8 psi or less because its damn cold, but the power is still there in the motor. Boosts gauges can be little bit misleading sometimes, but its all in the motor that counts that gives you the umph... and of course the whp that gets you pulling hard. Damn I miss that 2.4 motor and wouldn't mind on a car project to swap the LNF out for the 2.4L. My SRT-4 had electrical issues because it was the 1st gen, but it had a strong motor that Dodge ever invented. Now they lost their roots ever since the Caliber was released. Maybe they'll think twice of stop getting rid of a good selling car.

 

Isn't "learn down" just the PCM doing its job? It is set to hit a particular air load isn't it? It doesn't matter whether you are on the stock tune, GMS1, HPT, Trifecta, etc. Your car is only going to make as much power as the tune commands. That is actually REALLY cool if you ask me.

This means that if you have full bolt ons (i.e. better flow/efficiency), your car wont have to work as hard to reach the desired air load commanded by the tune.

Term, BYT, etc. HPT guys care to chime in?

 

This is very true. I wish everyone would stop calling it learn down. These computers base everything off of air loads, that's all...it's not trying to learn aftermarket parts out or anything..it just senses that it's hitting a higher air flow than it should be and adjusts from there. NO MATTER WHAT TUNE YOU HAVE your car will try to hit the desired air loads it's programmed to hit. And yes you will see some very slight gains with certain bolt-ons even without a retune. If you believe that the GMS1 tune removes and/or changes the way this computer tries to make power (via air loads) and essentially removes what's referred to around here as "learn down"...then you are delusional. Ask anyone around here that has tuned over the GMS1 tune and has seen its inner workings...it operates the EXACT same way as the standard operating system...just recalibrated with higher air loads and capable of reading the higher bar map sensors...that's all.

 

I love your answer, your in the right ballpark. Just like an operating system is what the PCM is programmed to do. The computer will do what you want it to do. Like the person who designed the GMS1 tune to be programmed in the PCM for safety and pushing more hp for what the car can handle.