99 Si

[David_B]

Ok I have a 99 Si and I want to know if a 4-2-1 header would help me on a 1000ft track? I'm planning on getting a 4-1 header, but not in time for the big import race at my local track. I can get a 4-2-1 really cheap. Would it help me?

Thanks for any help
David

[90CRXZCSi]

most definitley. 4-2-1 helps the low end and 4-1 is more for top end. If your looking for the 1000', the 4-2-1 would work great.

[David_B]

But what I don't understand is that if I launch at 4500-5000rpm's, then i'm not in the low rpm's and i'm in the mid rpm's for a sec. Anything that will help me i'm gonna do before the big race. Weather or not I keep it is a different story. Thanks for the advice.

David

[Plastic_Fork]

Just wondering, but how does a 4-2-1 header improve low end whereas a 4-1 improve top end? That doesn't make sense to me -- I thought the 4-2-1 flowed slightly less than the 4-1 due to it's design. How does that help low-end? Not trying to give you crap, but I'm genuinely curious.

[90CRXZCSi]

well the ITR has a 4-1 header and if you look at dyno charts it shows the power more in the top end. They even tried putting on a 4-2-1 header on an ITR, and all i can say is that the owner wasnt pleased with the results from it.

[Ace$nyper]

the 4-2-1 creates a lil backpressure while a 4-1 doesn't really make any yet gives you more top end while 4-2-1 is for the whole powerband.

[90CRXZCSi]

very well said.

[David_B]

So will it help any or not? I don't want it to hurt me but I don't see how it would hurt me?

[Ace$nyper]

help yup alot headers are a great upgrade me for a Daily driver i'd take 4-2-1s cause 4-1s can suck away your lowend tourqe (lol honda low-end tourqe)

[David_B]

Ok I got another question. Will a 94-01 gsr header fit on my si?

Thanks
David

[90CRXZCSi]

yes it will bolt right up. I have a GSR DC sport Header on my B16A head. 94-99, the header was a little shorter and 00-01, they made it a little longer, so you will have to find out which one fits better.