a friend of mine told me that i should keep my cats and go 3" pipe with no muffler, wut do you guys think about that i just wanted to get the HKS cat back but now im confused!!
does your friend have a speed 3? that would be like me telling an srt guy what he should do. how the hell would i know??
before you listen to anyone or before anyone can tell what the best option would be you have to figure out what you want to accomplish out of changing the exhaust. do you want more power, do you want it louder? deeper? raspy? etc....
there are threads around that have all kinds of sound clips of different options. SOme people just removed a resonator or two and others have cat-backs or test pipes. There is a million possible combos that you could go with. Dig around a bit and find the one that fits your desires most. Or if you like the way your buddies speed6 sounds, do what he did.
a friend of mine told me that i should keep my cats and go 3" pipe with no muffler, wut do you guys think about that i just wanted to get the HKS cat back but now im confused!!
What are you going for? The solution to more power is different than the solution for a change in sound volume or tone. There are enough dyno results posted here to pretty much settle the issue that cat back systems with 3 inch pipes, with or without muffler will realize very little power gain, unless you also upgrade to a bigger turbo.
The real restriction is upstream of the cat back -- the problem is with a very restrictive downpipe and very restrictive cats. That's where the power gains lie -- a good aftermarket DP and RP combo without cats will realize the most power gain. There are also good DP/RP combos with high flow cats (the stock ones suck), that will get close to catless in exhaust flow.
The muffler and the two resos in the stock system are straight through designs with very little restriction.
Now if it's a different sound you are looking for, there are all sorts of high quality cat back systems on the market. You can listen to the clips and pick the one you like best. But they will not give you much, if any, real power gain. In fact, the stock cat back system will easily flow up to around 300 whp and is more than adequate for any mods up to that power level.
