I just picked up a 87 TII and I am building an engine for the car. When i was looking at some of the specs between the 86-88 and 89-91 the horsepower and torque ratings differed by about 16hp and 17fpt Why is this?

One more queston, since the engine is being built is it worth spending 300 extra to have my mechanic port it?

If you guys could clairify this it would be a big help to me!

Yes it is definitely worth it. And the hp differences i think have to do with like intake design or something.

what kind of a horsepower gain does porting intail?

The s5 engine has higher compression and the turbo makes more boost.



How much power you get depends on how the person ports it. Some people do better jobs than others. It's more or less an art. A careful hand is a valuable asset. I think like around 15% more power can be gained. Not sure though.

Thanks thats helpfull, so when building the engine, using parts from an s5 engine would be the better bet!

check the engine building and porting section. some decent info there