Every serious Gp owner seems to have an upgaded or whatever downpipe. Can someone simly explain why people change it, what it does, and how it helps increase hp?
Thanks

Making horsepower is about moving air and fuel. The more air and fuel (in the right ratio) that you can move, the more horsepower you get.

CAI, smaller pulley, etc gets more air into the engine.

Headers or ported manifolds and a DP will help get the exhaust out of the engine.

You need it all, but a downpipe is a good place to start if you can't afford headers and the rest.

If you spend all your time getting air into the engine, and no way to get the exhaust out, it leads to hot spots and KR which will damage your engine.

So what would you reccommend for a stock GT thats going to be running the K&N intake kit from pfyc.com
3in?

also...what is a u-bend delete.

I've only got the K&N drop-in, so I cannot answer that one. Someone else can.

U-Bend Delete is where you remove a pipe that takes an unneccessary route around some (steering?) components on the underbody. That helps remove some restriction, helping move the exhaust gasses faster and easier.

Welcome to the board.

http://www.pfyc.com/pc/WB5001/GPEXH/U-Bend+Replacement.html
that is the u-bend in the exhaust

I think the U-bend is actually bent for an o2 sensor...a U-bend delete is when you take out the bend and have a straight pipe instead with the o2 sensor off to the side instead of on top...you can look and see it under your car(right before the cat)or look on zzperfomance.com they show a good pic i think...its really cheap and a good way to free up some hp...yet i still haven't bought one...lol someone can correct me if i'm wrong but i'm pretty sure thats the jist of it..

~stauffie

OEM D/P's are double-walled, 3" outer and something like 2 1/8" inner.

https://www.zzperformance.com/grand_prix/products1.php?id=551&catid=110


Read all the information they have on there.