jump454

i'm wondering what caused the jump in horsepower between these two years. was it just the ecu, or exhaust and intake or is it a totally different housing and rotors? im just curious cause the first one is easily changed. the second doesnt matter if i get aftermarket hop up parts. but the third ones a little harder to change. any help appreciated.

rarson

First off, the rotors are 9.7:1 as opposed to 9.4:1. Not only that, but they are also lighter. Then add in the VDI intake, which I believe actually accounts for a large amount of the horsepower difference.

Whizbang

cough cough FC FAQ cough cough...top of forum cough


there are ECU differences obviously from different fuel maps (1000 rpm higher than the s4), emissions needs, and the fact the motors are different in terms of manifold construction and compression ratio.

Icemark

There is actually very little increase on the non turbos as peak torque didn't go up at all (well 3 ft/lbs) and since the torque is really what moves the car.. well

But the HP increases came from better flowing intake, high compression rotors, and revised engine management.

jump454

i'm a retard. i meant in the na model. sorry i didnt clarify. but i was just curious if i was starting at a disadvantage compared to the 89 model. i could see the compression bump as a power adder but i didnt know if the other things you said applied to the na models too or just the turbos.

rarson

Mark, I have to disagree. Torque doesn't necessarily move anything. Horsepower, however, does imply movement. Torque is not a unit of work.

Icemark

well if you want to get down to the nity grity, wattage would be more accurate, but they don't rate motors on wattage in the USA