I have stock headers, stock cats, stock midpipe. Whipple at 10psi.

A while back I swapped out my flowmasters for SLP Loudmouths because I wanted something louder. Well, it was a little to loud and sounded really rowdy/nasty under heavy throttle. I liked the tone of the exhaust under normal throttle. After that, a set of magnaflow bullet/resonator mufflers were put in mid-way through the exhaust to quiet it down a bit, and hopfully get rid of the nasty sound in upper RPMs. This did get the volume down just perfect, but the exhaust still has the rowdy/nasty sound when I get on it (more than 1/2 throttle probably). Normal driving, it's perfect, I love it :-)

I'd like to keep roughly the same volume I have now, but I want to get rid of that rowdy/nasty sound in the upper RPMs under heavy throttle. I'm not quite sure how to describe the sound, I'm not sure if it's the 'trumpeting' that some people have mentioned or not, but either way I don't like it, it just doesn't sound good.

I'm looking at possibly trying a different midpipe, possibly a prochamber (with stock or aftermarket cats) or an X pipe (with stock or aftermarket cats). Would either the prochamber, or an X pipe help out the rowdy/nasty sound in the upper RPMs? I'm pretty sure both of them will change the tone alot, I'm fine with that, I just want the nasty sound to go away up high, but I don't want to go back to the relatively quiet exhaust of the flowmasters.

Here's the two I'm thinking about trying,

Bassani X pipe with new cats: http://www.lethalperformance.com/pag...cats-3-pc.html
Prochamber (stock cats): http://www.lethalperformance.com/pag...tock-cats.html

So, I don't want to touch the headers for emissions reasons, and I won't run without cats for the same reason. I know most of yall will probably suggest longtubes and no cats, but I'm not going to go this route, so long as I stay in California.

Thanks for any help! I've looked at alot of exhaust threads, but it seems that most combinations are running no cats, or longtubes.

 

Spintech has an X-pipe and axle backs.Its a very aggressive combo. If I ever hit another jackpot up in Central City,CO I'll spend that happy money on such a set up.

 

Go with the prochamber or a hi-flow catted h-pipe, an x-pipe will just make it worse.

 

I have prochamber-pypes mid muffler-with slp LM's out back. IMO, NOTHING COMES CLOSE!! You can just buy the pypes m80 muffler and have that installed in the mid section...

 

Do you have cats? or no? I've been looking, but I can't seem to find anyone who has a prochamber WITH cats, and SLP (or other 'no muffler' mufflers). The sound I have with the SLP's and the mid-pipe bullet/resonators is very much the same in terms of tone from when I just had the SLP pipes, just not as loud.

I'm leaning towards the prochamber, I've read several places that x pipes can sound raspy.

 

MTAS is running stock cats with the Prochamber and Hooker aerochambers - sounds amazing

deep, bassy and refined sound.

I am not sure if adding the Prochamber will 'fix' the issue in question - I really think its the LMs man

Before adding something midpipe, perhaps change your axlebacks?

 

There are several highflow cats that will work with the prochamber. I recently put in a set of magnaflow high cats