Check out Horsepowerfreaks.com
i would get the set of headers, full exhaust system, fuel injectors, cold air intake..
go to andysautosport.com and look around at superchargers, or turbos depending on what you would prefer, I know there are supercharger KITS and turbo kits out there for your car I just didn't find anything from a quick google search. Those would be the biggest in gains for hp.
Personally- I would also consider a full coilover suspension set up for a more race feel ride, and less roll in corners. In general though the cadillacs are heavy cars, you're going to need a turbo or supercharger to really push the engine to be as fast as you probably want it to be.
Don't be surprised if you're going to be spending at minimum 5k dollars on just buying a kit, and then having to pay a professional to install it unless you feel you're really up to the task yourself.
if it's a manual don't forget to upgrade the clutch , driveshaft, etc if you're going to up the power that much on it.
· 6 years ago