jyfatboy

[jyfatboy]

okay guys need help on picking out intake maniflod. I have a 1998 z28, the short block is stock and i have a comp cams 600" list camp and ported heads and mac mid lenght headers. Have anybody tried a thphoon intake.

[Chevythunder17]

Go with an LS6, good gains for modest money. Anything larger would be overkill for what you have.

[2001hawk]

The LS1 and LS6 manifolds are both nylon. The FAST LSX manifold is composite. I would go with something along those lines, because they are won't heat soak like metal ones will. Unless you are running alot of nitrous or boost, but since you didn't mention either that is my $0.02. The 78mm LS6 manifold is going to be cheaper as stated above (couple hundred bucks used), but you can get 90mm with FAST's LSX and you may want to consider it since said you have ported heads and a high lift cam. Just keep in mind that you are talking a grand or more if you go 90mm because you also have to get a throttle body. When I bought my 90mm LSX manifold it was $1,050 I think, Texas Speed was running a combo deal.

[jyfatboy]

thanks for the advise .i plan on putting a 150 shot of nitrous on the engine, would you suggest the fast intake manifold with a 90mm throttle body.

[nhraformula]

you want the fast intake. it will go good with your set up and N20

[2001hawk]

From what I have read if you are pushing a lot of lift and RPM's, that is when the 90mm becomes most effective. I wouldn't spend the time and money to go back 78mm. It is a pretty straight forward mod comes with good instructions. It went on my 02 WS6 so I don't know how the drilling out the hole for the EGR will go for you, but it has a big area there and you will need a dremel. The hole thing took me around a day, of course I was taking my time, B/Sing, and hadn't done it before. As far as whether I actually picked up any power and how much I don't know cause I didn't dyno it beforehand, but that car pushes pretty hard. Hope it helps. Are you going dry shot or wet?