Guess my exhaust was restrictive.

[haywire4130]

your next upgrade should be a pair of straight-thru mufflers like magnaflows or dynomax ultra-flo... the chambered hooker design is restrictive and droney, but to each his own-

 

[theCATman]

your next upgrade should be a pair of straight-thru mufflers like magnaflows or dynomax ultra-flo... the chambered hooker design is restrictive and droney, but to each his own-

Not true. The Aerochamber muffler is NOT a chambered/baffle design like a Flowmaster, AND they flow extremely well. They are basicly a straight thru design, they just don't use a generic perforated pipe & fiberglass packing.

I just put on an electric powered cutout this spring & I have zero boost difference between open & closed (3" single exhaust, THDP & Aerochamber muffler)

I wasn't expecting more power with the cutout open, as I knew the Hooker muffler flowed great. I just wanted the noise & nasty turbo whistle

OP.... stick with the Aerochambers. They are a great muffer.

 

[haywire4130]

Its possible they updated the mufflers that come in the hooker kit, the ones that were on my gn were a 10 yr old system, replacing them with magnaflows yielded me similar gains in boost and spoolup that the op was talking about after switching from atr's. Id love to see a cutaway of the aerochambers, the ones I had were very flowmaster-esque and my car didnt like them-

 

[theCATman]

Hooker (Holley) had to have changed them then. They don't have welded plates\baffles at all now.

 

[turbofabricator]

We are running 10.0's on a 3" down pipe and a 2.5" dual system with THREE ultra flow mufflers. How fast are you all running needing a single 4" or even a 3.5" down pipe". Years ago we were running 9.teens with a single 3.5" down pipe and dual 3" system with three mufflers. Both cars are very quite and TRUELY ZERO DRONE. Un capping the 3.5" DP it gained only SIX HP on a chassis Dyno. Some of you need to rethink your goals. And anyone that says that a single shot system, in any diameter, that doesn't drone ......must hear WAY worse than me. (And after smacking rivets on airplanes for nearly 30 years, my hearing sux! Huh?........what?)

 

[Mike T]

I have a 3" down pipe, home made test tube, original (from where the cat was) back & a 20 year old stock style Dynomax single muffler that is very quiet. This was all left in place after my new build just to get the car on the road. Since running the car I am reluctant to change a thing, the 70 with an 85 housing spools very well with only a 3 k converter and the car pulls very hard all the way to 5500 rpm. This is one of the things I like about these cars some combos that make no since sometimes work.