So I have found very many usefull links on this site and I have been reading alot, I can see why Mr. TheShodams point in the Last forum, any ways I do understand what the A/R is and how it affects the performance Im just not sure which to go with as I have nothing to compare the different sizes to, also I was told to setup a fuel return line, I went into model specific forums and searched but did not see, Please explain,,, I Know EFI systems return fuel to tank do theese not have? Any ways The car is an ACURA RSXtype-S low comp pistons rods valves retainers,,, Looking for around 325-350 maybe someday get up to 400hp It is a daily driver and hitting tracks on the weekend, also what kind of boost is safe for theese k20s with crower rods and wiesco pistons 9:1 and my friend has the same pistons but are 8:1 would trade should I stick or trade he apparantly wants the 9s cause he decided just to do a low boost app for some reason but I dont want it to be a super dog when its not boostin, also since your reading my gf just happend to somehow run over some charge piping,,, sad day, but i was thinkin about switching I had 3inch pipe but dont no if its necessary and a smaller pipe might be better? well thanks for any info, sorry its s long I thought I had almost every thing figured out but i guess not thanks,,