986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post - HP, how much can a LIL 2.5L take? How do they Blow?

pk2 · 12-27-2007, 04:03 PM

Gary, Brucelee, Speedster guy, thanks for the input.

Truth is it’s already supercharged and depending who you talk too, it’s between 250-280hp (at the crank, I’ve yet to put it on a dyno though). But with a %10 or so change in the pulley and h2o/meth injection, I could pick up another 1-2 psi, or about 15-25 hp.

I’m not crazy about stressing the _ell out of the little 2.5 motor. And if I wasn’t already where I’m at I’d consider a 3.2, 3.4 or 3.6. I am surprised though at the relatively modest power gain with such significant displacement increases (and hassle), not much bang for the buck.

My SC mod pondering works out to be about $25 per hp. A bargain if I can get the psi I need without going over the SC’s 14k rpm max mark, (gotta do the math) and the engine doesn’t explode.

With H2O/Alcohol injection and competent tuning, I’m not too too concerned with the usual top end failures. It’s the rest of the gear I’m concerned about, whats going to crack under the strain and at what point.

Regards, PK

Gary, Doesn’t the maker of your setup claim 290 HP? How is it and the motor holding up?

12-27-2007, 04:03 PM	#8
pk2 Registered User Join Date: Aug 2007 Location: Tustin Ca. Posts: 449	Gary, Brucelee, Speedster guy, thanks for the input. Truth is it’s already supercharged and depending who you talk too, it’s between 250-280hp (at the crank, I’ve yet to put it on a dyno though). But with a %10 or so change in the pulley and h2o/meth injection, I could pick up another 1-2 psi, or about 15-25 hp. I’m not crazy about stressing the _ell out of the little 2.5 motor. And if I wasn’t already where I’m at I’d consider a 3.2, 3.4 or 3.6. I am surprised though at the relatively modest power gain with such significant displacement increases (and hassle), not much bang for the buck. My SC mod pondering works out to be about $25 per hp. A bargain if I can get the psi I need without going over the SC’s 14k rpm max mark, (gotta do the math) and the engine doesn’t explode. With H2O/Alcohol injection and competent tuning, I’m not too too concerned with the usual top end failures. It’s the rest of the gear I’m concerned about, whats going to crack under the strain and at what point. Regards, PK Gary, Doesn’t the maker of your setup claim 290 HP? How is it and the motor holding up? __________________ http://img87.imageshack.us/img87/163...58x6ir4.th.jpg 99 Supercharged 2.5L Last edited by pk2; 12-27-2007 at 06:12 PM.