Re: s4/s5 cam combo
if you increase lift, you will increase power on a turbo car. on a turbo car, unless it has a monster turbo, increased overlap (generally a product of increased duration) will more than likely reduce power. if you got these cams, youre going to want to reduce overlap to a minimum unless youre running a monster turbo (my turbo would be the minimum).
but, since youre asking, you probably dont really know how, or have the resources to do this kind of testing, so my suggestion is to stick with what is known to work: S3s or S4s with 2.5* retard on intake and 2.5* advance on exhaust. this would close up your overlap nicely, spool your turbo faster and fatten up the midrange. another good combo is some C1s with similiar cam timing, but they require valve springs, and every motor is different, so i would use that cam timing as a starting point.
with the S4/S5 combo, you could sit on the dyno for hours (at, what, $200 an hour? ouch!) and do nothing but lose power and have a nice, lazy turbo.
Last edited by Rockwood; 07-09-2004 at 12:27 PM.