i have bbk longtubes and off road h, with flows
i have 2.5in piping on the catback but i want to make it sound a little cleaner.
does the size piping help?
can i just weld in mufflers or should i get new catback.

what kind?

 

I would do magnaflow, not magnapacks, for a cleaner sound I think. A catted midpipe would also fix your problem most likely.

 

I am set on Magnapacks, they have a deep, low rumble at idle, but at WOT, CAN YOU SAY NASCAR(at least that is what I think it sounds like when I go underneath a bridge, lol). But, that is with my SLP off road X-pipe. I am going to see how the modified H-pipe will sound very soon, I believe the UPS delivery date is on the 20th. I may go have it installed today if my friend at the shop isn't too tied up.

What do you mean by"sound a little cleaner" ? Do you have the stock cat-back or is it from flowmaster or aftermarket? I've heard that spintech has a little better sound than flowmaster if you still wanted to stick with a simular sized muffler. Spintech has a circlular pattern of baffles vs straight angles in the flowmaster. You can try this site to listen to certain exaust systems: http://www.mustangexhaust.com/

Is the exaust popping or backfiring during decelleration? Backfiring or popping may result due to too much unburned gas in the exaust. This can usually be fixed by doing a tuneup(new plugs, fuel filter, cleaning the air filter etc). I would go even as far as to check your O2 sensors. If those two things aren't the problem, send the car to a dyno and test the performance by adjusting the air/fuel ratio. Unless you're pumping out 500+ HP, your car needs that 2 1/2" pipe that allows for the correct back pressure to scavenge exaust fumes efficiently. If you go with a larger diameter pipe you would loose tq/hp.

I have the same year Mach1 and I am hoping this setup will work to give me a deep throaty muscle car sound: SLP 1 3/4" longtubes + O/R Pypes customized H-pipe + magnaflow magnapacks. I will be going with Comp Xtreme stage 2 cams with ported heads and intake when I come back from Iraq

 

Flows are garbage lose em you'll be happier

 

Are you STILL being a grouchy bastard rebel? LOL sheesh..

mmeeehhh, I have to agree though, flows are pretty crappy.. the magna's I think are ok though I don't know why you'd want to clean up the sound.. 4v's are SUPPOSED to sound loud n' dirty.. :-D

 

Any vids of your setup?

 

i dont but i can make a video and the flows just sound cheap....it sounds nasty at WOT but it sounds to dirty when cruising or at low rpms.