OK i have LT's no cats and i had the stock muffler on but i have just put on a Flowmaste muffler and put the stock tips on it but i get the awfull raspy sound when ever the car goes above 3000 rpms..

A friend welded it on for me if he left a leak would that cause it to be very raspy or is that just how flowmasters sound?

 

no cats will do it.. ive been looking into a bunch of stuff to get rid of it..
Stick dynatech cones in the y pipe or on each end of the header to get rid of the rasp.. it wont really quiet the car just get rid of the rasp..
Another bullet muffler on I pipe will do it...

My friend has long tubes, off road 3 inch ypipe and hooker cat back and he has no rasp...

So try going with Hooker cuz the flowmaster muffler isnt that great anyways.

I think im going to stick cats back on the car... some high flow carsounds should support 430rwhp without any power loss.

 

Most likely because of the twin tips you have, I remember changing to a single out exhaust tip, and it changed the sound to a more deeper basy sound..........

 

When you said you have no cats, did you mean that you have gutted/hollowed out cats or an off road pipe in place of the cats?

I heard the gutted cats will cause the rasp and the blatty sound but the Off Road pipe will not.

Thx,
Claude

 

i have long tube headers so i have no cats at all.
Tips? what kind\shape of tip would give the deepest bass sound to the exhaust?

dynatech cones what are those? do they go inside of the exhaust or would i have to get a shop to put them in?

Thanks for the quick response

 

Raspiness is generally caused by the exhaust pulses overlapping eachother. A hollowed out cat housing will cause some raspiness cause it distorts the pulses while they're taveling down the exhaust tract. The cross-flow flowmaster is known for raspiness since it's baffles distort the pulses. The flowmasters the mustangs use sound great due to thier more straight-though nature rather than the crossflow design. And the mustangs just sound damn good anyway due to their firing order.

I have MAC headers, stock cat with the catalyst drilled out to match the diameter of the in/out tubes (like a straight-though muffler), and the hooker catback... it doesn't get raspy at all at any rpm and pulsates nicely. VERY deep tone. Headers usually "clean up" the LT1s exhaust note since they align the pulses better than the manifolds.

 

Click here for the dynatech cones. I just ordered one and hopefully it will get rid of the rasp. It sounds like puke. I am running flowmasters with LT and Offroad pipe.
I'll keep the board posted.