i just got a 99 RS and it has a magnaflow muffler on it along with new piping from the axel back. The piping ony looks like its about 2.25 or 2.5 diamater. What is the stock pipe size? I am gonna get all new piping from the cat back and eventually cobb headers. Is 3 inch piping too big? When i get the headers will i have any problem installing them since i have custom exhuast?
I wouldn't go any bigger than a 2.5 unless you are planning on adding a turbo later. Anything bigger than 2.5 you run the risk of loosing some low end torque. I think stock size is 2, but not positive on that.
Yup! 2.25" for the best mid-range torque and 2.5" sacrifices the low end for the best top-end. The HP differences aren't anything to be crazy over. I loved the usable torque of my 2.25" exhaust when I had my RS.
If you want Cobb headers I'm selling the set off of my 01 RS. They are the equal length catless with the coating. the thread is under buy-sell Pete's RS...they are tentatively spoken for by lilred but if he doesn't want them I can help you out there.
well..for my custom cat back i did a 2 inch diam...pipe from the catalytic....(about 18 inches long) then its widens up to 2.5 inches all the way to the muffler...it looks funny and wierd..but i like the way how air flows right straight out...not much bends at all..just a straight pipe to the muffler...well if you like to see..i'll bring my car to firestone tonight...and a flashlight too...it gives me good power...lots of low ends and high ends too... wagonL
