Well as some of you may know i have a single...its a hks can with i think 2 1/2 inch pipes....i also put a invidia test pipe (i know Ricky ) I also have a AUT radiator plate with gutted air box and knN filter. I let cody drive my car (stealth) and he even said my car got signifigant power gains from stock. I was wondering if i would gain more.....or lose power if i went to 3 inches from test pipe back. I have the invidia test pipe...and plan to get the invidia header (dyno says 10-15hp) but what i read backs it up at least to 7 hp. Anyway......i plan to get the header, and 4.57's...that will be all for speed.


And im pretty sure my mods added 10-15hp because i raced a 05' evo with catback and high flow cat......he raped my stock, but when i got my setup i have now...WITH a bad clutch and gearbox....he would pull me and i would fall back, then shoot right back up but couldnt pass him each time. Then a s2k with gears drove mine and said we would be about the same.....so i dont want to hear "our cars dont respond to mods!" LOL



Any info on 3 inch exhaust will be appreciated.....

 

With a NA setup too little back pressure can really hurt your performance. Typically you don't want to put a 3" exhaust on a NA setup.

 

I second what Justin says; even with a supercharged car, I ended up having 'too big' of an exhaust at one point and had to revert back to a previous setup. With a turbo, a 3" exhaust should be no problem, but I wouldn't do it N/A...

You have to remember that the engine is nothing more than an air pump. The more efficiently it can pump air in and out of it, the more horsepower it will make. To accomplish this, you need to make sure that your exhaust pulses are not having the opportunity to slow down too much while in the exhaust... Otherwise you will be causing a 'stop/start/stop/start' pattern of flow within the exhaust that costs you power because the air pump (engine) has to restart the flow of air again after every exhaust stroke. If you can keep the velocity up (by not letting it slow down into too large of a chamber (exhaust), then you minimize that effect and the engine can pump the air out much more efficiently.

And that concludes your extremely basic and overly simplified Physics lesson for today...

Ricky

 

P.S Justin C...backpressure is a myth......


Its the velocity of the air coming out of the exhaust your referring to...RICER NUB

 

If you are so damn smart why don't you quit posting asking for information about mods ?

Yes, Ricky did say it best. Back pressure is the force that is keeping the air from flowing out of the exhaust too quickly...."slowing the velocity of gases". It is actually a pressure that sucks air out of the exhaust.

 

dont forget vafc~!

 

did you google that?

 

No

 

Speaking of power mods....i raced stealth which is a 2001 ap1 spa yellow with 4.57's and everything else stock.

Im identical to a s2k with 4.57's, we ran up to about 110. Now just wait till i slap some 4.57's on my car, along with a greddy emanage im getting from him....i should be pretty quick.


p.s ricky whats the best brand for air fuel ratio gauges.....im gonna need it when i get my emanage....so i can tell if im running lean or rich without having to use my nose (loses a billion brain cells each time i try this)

 

david you should race at autocross on sunday april 15th! i wana go if i can get outa work i hope lotsa people are there as this is the first one ive been to in a yearish