i have an 2009 cobalt ss/tc.

i know the hhr stage 1 comes with new map sensor and you need to get the tune from gm.

what if i buy a superchip tuner or buy an ecm from someone with a custom tune? do i need a new map? i know what and how a map works... but i dont see anyone including a map with a tuner or ecm.

also what exactly gets changed when you use a tuner? i was told the rpm limit and speed limiter get changed in addition to the new tune and a code reader. (superchip). what does hahn's tuner give me? how about the gm stage 1? i think 1st and 2nd gear rpm limit is now 7k and 3,4,5 are also raised to 7500k?

does the tune get rid of that little studder feeling when your at full acceleration and the ecm is limiting the power output of the motor. kinda feels like the wastegate is opening and closing really quick.

let me know everything and anything about these tunes. thanks guys

 

Idk what a tuner does but getting a custom tune is what i got and they just changed my afr and possibly timing. as for using a different map sensor i don't think it can be done w/o the gm tune only because they read different voltage and i don't think any tuning has unlocked that yet.

 

what does the tuner actually change? anyone?

 

It depends. Most of your power is coming from up'ed boost levels. Trifecta is what I know since I have it, and they push about 22-23lbs. Vince (Trifecta) does other tweeks that I don't know about for reliability and to squeak out some more torque.

 

the tuner makes it slow

 

well I can tell you a hp tune will yield 343tq and 308 hp and runs 13.5 with a 106.8 trap in the quarter but I've blown 2 map sensors so I would say save your money and go with the gm kit

vid of my dyno...

http://www.youtube.com/watch?v=rBbVKB95Tn4

 

I can tell you that an HP tune will get me 12's soon, on an otherwise stock motor (no bolt ons).

I would go with an HP tune, but just be careful when you, or someone else tunes it, so you know you aren't hitting the 255 kpa MAP limit alot. Then it will last fine.