I can't take it.

Full length large tube (1 3/4) hooker headers, hooker 3" y-pipe into a single 3" cat, then it goes into a y, 2 1/4" pipes into two STOCK mufflers.

It's loud. I don't like it.

What do you guys think. If i put two 3" cats right after the headers, then neck down to 2 1/4" all the way into the mufflers, and have a cross over pipe somewhere to reduce resonance?

-- Joe

 

Earplugs maybe? Or a louder stereo? LOL.

I'd try the cats first.

I ma getting annoyed with popping from my loud exhaust so I may end up going with a cat too.
Going to close up the borla completely first and see if that changes anything.

 

Where are the tail pipes and where do they point? This makes a bigger difference than you would imagine. If your tail pipes stick out past the end of the car a tad, or if they are tucked under the bumper and point down, it'll be much more tolerable than having straight pipes that end before the bumper. On my IROC I've got 1 5/8" headers into a 2.5" y-pipe into a 3" intermediate pipe (no cat), and through a single 3" spintech that dumps on the driver side. I slash-cut a 45* elbow and tucked it up out of sight. With the exhaust dumping down near the back of the car, even with my lack of any actual exhaust, I get no drone and no resonance. In 4th and 5th gear, I barely hear the exhaust, if at all.

On the other hand, in my Corvette, the pipes exit horizontally beneath the rear bumper, and even with a cat and 2 real mufflers, the drone up certain hills drives me nuts. Turndowns that aren't far enough back can have a smilar effect.

 

I re-did the system and it's a little better. I still get some drone or something under load at low rpms.

I have:

Hooker long tube headers. I welded up some flowmaster reducer flanges, into 2 1/4" pipes. the pipes snake down both sides of the transmission. Then they run side by side and an H is welded in. Shortly after the H, they go into two bullet cats. After the cats they go to each side of the car, into turbo mufflers with LT1 tips. The Tips exit about a half inch from the rear bumper cover.

It's true dual, and almost an equal length from side to side, with the h-pipe.

WOT, idle is great. but the 1200-1800rpm stuff is loud.

-- Joe

 

i totally understand. i drove a 93 at work with everything stock but flowmaster mufflers. there was a terrible drone at that RPM range and it made me want to tap the gas to downshift or totally let off to upshift (it was an auto). its something about C4's...my camaro is a tad louder than that 93 and its not near as bad. maybe the C4 has less sound deadening... But i am comparing an LT1 to a TPI

for my future C4 project im looking for the best performing yet quietest muffler i can find. sort of a sleeper approach. i want C6 owners to think its a stock or just mildly modded C4. does anyone make mufflers like that? i have also seen those cone things u can put in your exhaust. they say no backpressure is introduced