71 GTO muffler
 

I have a 71 GTO with the 455 cid (not HO) engine, RAIV manifolds and a 2 1/2" Flowmaster exhaust with H pipe and Flowmaster mufflers (17" case).

Does anyone have a recommendation for a louder muffler replacement than the Flowmasters; they seem pretty quiet while cruising and accelerating. They do drone some at 55 mph but not really annoying. I researched thru previous posts and didn't see a Flowmaster replacement experience.

Any recommendation would be appreciated.

On recent pontiacs I have had Flow Master 40's, Magnaflow, Dynomax Super Turbo, and Dynomax UltraFlow. For a street cruiser with a mello tone and zero drone I like the SuperTurbo. For a more aggressive sound and reasonable highway tone the Ultraflow is great. Cant think of anything that I would like the 40s on!!

Sent from my SM-G965U using Tapatalk

The 13" case length muffler will be louder. FlowTech, Thrush Welded and Flowmaster 40 are all pretty loud. I found the FlowTech and Thrush to have less interior resonance than the Flowmaster 40.

I pulled off a pair of Thrush Welded mufflers (2 chamber) and put on 13" case length AP Xlerators (people still call them Goerlich but they are AP) along with an H pipe a few years back. Bad move. I was thinking I would like a bit less noise but they are way too quiet and the H-pipe killed that "cammy" sounding idle it had with the Thrush and the Flowmasters.

My car has been in and out of the body shop and storage for the past 2 years and I really haven't driven it. When I finally picked it up at the body shop last week to bring it home, I thought it would naturally sound loud when I first heard it running again. Nope, sounded like a stock exhaust.

I like the sound of the Flowmaster 40’s but on my 69 TA clone I wanted something extremely loud so I went with the Flowmaster race mufflers- I think they are 10’s? It’s kind of obnoxious with dumps, but that’s what I wanted. Would sound very aggressive through full exhaust

I went and bought a pair of the Flowmaster Super 44's. Have not had them installed yet. They are supposed to be louder than the 40's I have on now but quieter than the Flowmaster 10's that I was going to buy. Mufflers will go on on the 16th by a professional ( I don't have the equipment OR the talent to do what the installer does).

Electric cutouts gives you exactly the sound you want anytime you want it with any muffler.

Loudest mufflers I am aware of are Spintech and Pypes violators. YouTube them to hear different cars with them