odarabla

iTrader: (1)

I think you need a dyno tune. I have true duals on my car with the magnaflow magna pack mufflers, H-pipe and There is no rasp and no back fires at all! There is a video in my sig you can click on and hear what my car sonds like at WOT. This is with a stock bottom end LS1.

brian_rs/ss

ok OP i have the same set up as u plus a cam i also get back fire but trust me its perfectly normal for this set up. its because the bullets are straight through, no baffles or anything, and when u shift or decel at just the right rpm the sudden change in flow through these really open free flowing pipes will let out a pop every once in a while. my car is dyno tuned and runs tip top. but if your air/fuel is off a little i'm sure thats not going to help so a tune couldn't hurt but it'll never completely go away with this set up.

http://www.youtube.com/watch?v=L1zk-tqQdX8

^at the end of the vid when i am driving away then decel listen closely...its normal.

Juicy J

iTrader: (5)

I have LT's and 2.5" H pipe with dynomax bullets. I have a cam as well. My set up is not raspy enough in my opinion. I like a little bit of rasp... call me a ricer. My set up creates almost no rasp.

LT1 Trash

i'm running TSP true duals w/dynomax bullets/ pacesetter LT's on my h/c ls1 and i love the way it sounds.

WICKED_Z

Sounded good to me.

D.Jones

iTrader: (5)

i think its just the nature bullet style mufflers to have rasp and back fire. It sounded pretty normal like how it should be. but the addition of cats would help with the rasp and backfire.

toslow5o

iTrader: (4)

the rasp is from lack of cats.

the popping is from having very little backpressure thanks to the free flowing bullets

i have rasp and popping with dual cutouts open but neither closed through the cat and muffler

put your cats on before u change the muffler and see if your happy. they're restrictive but they'll tone it down. different mufflers can have the same effect but it's expensive to keep buying the wrong ones