Well written rob, 2 questions, what about the free mods, waste gate rod adjustment, solenoid bypass? Care to share an opinion on those? Miller your thoughts are more than welcome as well, did alot of reading on those never saw any solid proof of damage or gain
I did not do any of the mentioned mods but have observed results when others have.
There were a number of people who did the wastegate rod length change and many lived to regret it.
Questions about the "WASTEGATE MOD" - Pontiac Solstice Forum
The problem is that if you go a little bit, it seems to improve performence but if you go a little bit further it really screws up performance. And there is no way to reset the wastegate actuation arm length. No GM approved procedure. They are apparently set at the manufacturer individually using a flow bench. Once the nut is locked down, the only option is to try and return to the same setting by visually looking at the rod.
People who have done the wastegate mod have experienced problems and gone back to GM to get them addressed and had a big hassel because they point at the tweaked adjustment and say they cant fix the car. So sorry.
The jury is also out about any improvements that result on a non-tuned car because of the way the ECM manages engine peramaters.
From all my reading the first thing you must have is a tune. Either the GMPP which provides significant performance without stressing the car, or a third party tune of which there are several. The second thing is get a high flow cat. It definately adds to hp.
You can get to 300+ WHP with the above easily. The car will run great, and will last a long time.
It is becoming ever clearer that as you get nearer to the 400 WHP region, the standard transmission becomes the weak link. See the threads about the 2-3 syncros going on a lot of tuned cars.
As you get above 400 hp, if you go to stickier tires and can actually hook up, then the rear axles become the weak link after the transmission has failed.
My personal choice was to go with a tune and hardware that got me a good honest 305 WHP and enjoy the much quicker and faster than stock car. When I decided to go above that power level I chose to go to the LS conversion because it makes the drive train bullet proof. As long as you do not put on really sticky tires, you cant hurt anything that is susceptible to damage and the rest you just cant hurt.