ok, people have been telling me to get 2.25" or 2.5" piping for my st. right now all i have is an intake, but i plan on getting the pulleys and other upgrades i can, and possibly even a turbo. but, i want a good size that wont slow me down now, but can also handle what future modifications i will be making. would 2.5" be good? will it cause back pressure right now or will i get some improvement with it?

2.5 will do u fine and can handle any mods up to runing a turbo passed 10 pounds..if you reach that point, i would suggust you get a 3inch

>

agreed, but dont go any larger then 2.5" untill u tubro, or ull have no backpressure and well...trouble

>
no, the fe head creates enough backpressure in its un-flowing design

>

so 3" is ok with an N/A motor?

>
I don't think you'd really see any hurt in it. Won't see any gain though.

ok, this talk about backpressure, isnt that just BS??
i mean the two stroke is easy to understand why it needs it but if you take a look at how a four stroke engine works what could possibly benefit from not getting rid of the exhausts faster?
The only thing i see could be a benefit by having a smaller exhaust diameter would be to have a higher exhaust velocity and therefore create a sort of vacuum in the exhaust when it closes to "suck" it out during the next exhaust stroke.
so, too small = the engine has to work against the backpressure to pump the gases out of the exhaust = loss in hp
too big = lose exhaust velocity = loss in hp

is this just a common confusion that people mix them up or is there another reason why?


This post has been edited by Predator: Apr 19, 2006 - 11:43 AM

buy it and dyno it

>
thats about right, wont be any gain n/a

so do you think i will see any gain with the 2.5"?