Im BTW which headers to buy. the zzp long tube header/dp, new cobalt addiction one, vibrant, or gmpp manifold. and why.

im not too worried about the price i just want some good power gains.
i know the question has been asked a bajillion times, im just writing a research paper and dont have any time to search.

i was thinking gmpp or a stock manifold ported, so i dont have to worry about the dealer hasseling me. but if it wont give me significant gains, then i dont want one. im really leaning twoards the zzp or the vibrant.

any help is appreciated. and i get a good discount on any gmpp parts and i pay no tax, thats why i was considering the honed/extruded manifold and maybe i can port it a little more.

thanks
-Anthony

 

The manifold is worth 1 whp i believe lol dyno proven. If you are worried about your warranty then don't get aftermarket, if you come to the darkside i suggest a cti longtube header, sounds good with good gains. Depends on what you want though.

 

You see more gains from an aftermarket header/ dp combo then you will from the gmpp one.. go with zzp midlength its amazing

 

i'll be adding a GMPP header next week, so i'll let you know how it goes
but i will be coupling that with a R.A.W DP

 

i love my zzp header/dp, and so do most people that have it. only thing i would suggest is to buy grade 8 nuts/bolts/washers prior to install. but it sounds great, not raspy at all, and can def. feel a difference over stock. the zzp was the only mod i've done so far that i actually felt a difference (bought the car with stage tune installed)

 

i have a vibrant header downpipe...i like it sounds real nice....and CEL is on from high flow cat

 

i think im going to go with zzp, its cheaper than the vibrant

if i order the zzp long tube header/dp should i get the 3in dp that has a 3in outlet, the 3in dp that has the 2.5 outlet or a 2.5 dp with the 2.5 outlet

im going to have a 2.7 and 60's with cooling mods before i get this header.

and obv im getting the 1.75in primaries

 

get the 3"

 

My two biggest improvements were the header and downpipe install (installed together so not sure which makes more power) and Matt's (Tune Time Performance) tune... Each of these gave the car a greater kick in the pants than the Stage II did when I upgraded from stock...

 

curious to know a reason, if my gmpp catback is only 2.5in.
i'll get the 3in if everyone thinks i should

and did you mean the 3in dp with the 3in exit or the 3 in dp with the 2.5 in exit

 

Fix0r3d

 

if you don't want to change your catback, then get the 2.5 exit. If you are not done with the car get the 3" it will make more power

ditch the catback your going to choke

 

^I agree

 

i dont know if i want to ditch it, i like the way it sounds.

 

then go with the 2.5 dp and see if they do a 2.25 exit

 

Corsa sounds similar...just a little louder.

If your aim is performance don't be a nancy boy

 

i dont really care about the catback, i want to keep mine because i like the way it sounds, i just wanted to get some headers to have a little less restriction in my exhaust when i run my 2.7

its not really performance, i really dont care to get headers, i just want them because i hear the stock mani is restrictive, and with a 2.7 pully i dont want a restrictive exhaust

 

your catback will become the restriction

 

my aim really is driveability and im not really keen on having super loud exhausts... been there done that.

well than maybe i can get my muffler shop to make me a 2.5 custom exhaust or maybe 3in

 

resonators are your friend

 

You should focus more on cooling mods than a header...

 

a header is a cooling mod

 

already got a dual pass and a cobra h/e

i'd prolly run 1 or 2 resonators

 

then go 2.5 you poon

run a high flow cat to, it will sound less raspy unless that is what you are after

 

It would be a good idea to look into meth if you are going down to a 2.7