I have an 04 SS Silverado which is pretty much stock except for a CAI and performance tune. It had a 2.5" dual in and 3"single out Flowmaster on it with the stock exit. 2 Months ago I had it cut off at the dual in and installed 2 2.5" single in-single out 40 series flowmasters that dump out in front of the rear wheel.

Since then I have noticed a real drop in power up until about 3500 rpm... I have read quit a few posts with people who have run into te same thing. What I want to do is keep the same exit but go to a 2.5" dual in dual out.

Does anyone know what would be best to get that low end back with this setup????

 

FloPro has a dual-in dual-out muffler. FloPro's claim to fame is for eliminating the resonance common with the 6.0L engines we have. I replaced my stock muffler (same as SSS) with a FloPro HD dual-in single-out muffler and kept the stock tail pipe. I have no drone and it is not loud unless you are half throttle or more. Dyno results for me showed an increase of something like 6 rwhp and 28 rwtq. If you want it loud, this may not be what you are looking for.

 

Tuning will get the power drop back and then some.

 

I had a PCM4Less tune on it before I had the exhaust done which was dialed in for dual exhaust.

 

So I was just wondering if throwing an H-pipe or X-pipe in would help with the low end power with my setup. Also, I had heard the X-pipe will quiet the exhaust some, is that true?