Since i wont go to college till next semester doing some car work ..

Ive done divorced flowmaster 40s ..removed air silencer .. K & N filter ..
was wondering how much of a gain should i expect from 25% UDP ?

 

5-8rwhp.

 

around what rpms?

 

That sounds a little high.
Get an intake spacer, $100 for dyno proven 5hp and 7 toruqe.

The gains for the intake spacer is in the mid rpm's, where they are needed most.

 

Intake spacer = paper weight.
Ifyou want hp, you need to go big: Heads, intakes cam.
Bolt-ons won't be noticable except in lightening your wallet.

 

Yeah if you have $2,500-$3,500+. Not everyone has or wants todrop that kind of money.For the money to power ratio, intake manifold spacers and pulleys are not a bad idea. There arecold air intake kits, that do almost absolutely nothing, that cost more than a pulley or spacer.

I DID notice a difference with both, manifold spacer and pulley, when I put them on my car. It wasn't anything like what ported heads could do but it is still an improvement over stock.

The more important thing he needs to know is that if he is going to supercharge his car soon or at all, he shouldn't get a pulley or manifold spacer because he'll need to take them both back off when he puts the supercharger on.

 

You'll get more power at the wheels, but the U/D pullies will make absolutly no difference in the acutal performance of the car as the power gain is generally up at the top of the powerband and not lower where it's needed.

In other words, if you're going to do mods, skip the cheap crap that offers little to no gains, and go right for the stuff that actually does make a difference.