SStolen

iTrader: (22)

I have dual cutouts in my y-pipe about a foot after the headers and I'm wondering if I'm gaining or losing power with them open. I can see gaining power through restrictive exhaust systems but what if I have a pretty good flowing catback? I've been reading alot of posts where people are saying that a 3" catback isn't enough for a 400+ rwhp engine so alot of people do duals or 4" catbacks like spintech. I would like to sell my cutouts and get something like a 4" spintech but I can't see it getting over the axle without banging and making a bunch of noise- my 3" loudmouth hits sometimes. I have a dual 3" into single 4" out QTP Y-pipe so I could do a true 4" system all the way back. Right now I have the y-pipe going into a 4-3" reducer and into my loudmouth and my buddy said that I'm losing hp because the reducer is slowing up flow or scavenging or something like that..??
The other problem I have is its freaking loud! I was thinking about doing a Borla exhaust and putting another electric cutout where the plate goes so I could really have the best of all worlds. It should be pretty quiet closed and only as restrictive as my loudmouth open.
Another idea I had was to take off the LM resonator and put a Borla sportsman XR1 muffler in its place. A guy on this website (CAL) says its pretty quiet at idle and light throttle under low rpms but loud when your on it. Anyone here been in the same boat? Sorry for the long post.

pewter99SS

I would think you are fine with the dual cut-outs, you may loose a couple lb.ft of torque with them as opposed to true duals, but you will more than likely get the same hp gains. As far as going with true duals, there is no way you need a set of 4" true duals. 2.5" would work fine and most only go with 3" duals. I've never even seen 4" true duals.

pewter99SS

btw, if you really think about selling the dual electric cut-out Y-pipe, I would be interested in buying it, that is what I am planning on going to next.