As I said in a previous post, I picked up about 6 hp with headers, and high-flow cats. I got another 4 hp or so with the addition of a TTP cold air intake. That gives only a 10 hp or so increase on my 2000 2.7L boxster with modding the intake and exhaust systems.
That increase is significantly less than many of the claims that are made for such mods, but I think those are pretty realistic numbers for improvements of the 2.7L engine. As i understand it, both the 2.5L and 3.2L engines respond better with more hp with some of these same mods.
When I chipped the car, I picked up a little over 12 additional hp on the dyno. That means that depending on the dyno run, I am doing these days, I am only getting 20-25 hp over stock than stock with a full-on intake, exhaust and chip mod of the car (about 205 hp at the wheels). Again, much less than some of the claims for these mods. That being said, the car runs great, it is quite responsive and I love the sound of the exhaust, but those additional horses were not cheap....
Ed
