Who's muffler are you guys using that helps tone down your race car but doesn't hurt the overall performance much? I currently just have 6" Schoenfeld Race Muffler on my car, but looking to quiet the car down some. Would like something that milds the sound down, but doesn't sound like a mustang going down the track either.

Pretty much any straight thru muffler will be zero loss,unless it necks down the exhaust size. If you have 3" collectors and exhaust a 3" straight thru muffler will be zero loss.
Bigger mufflerbodyvolume will make the car quieter.
Mufflers further away from the collectors will help tame down the sound alitle aswell.
X or H pipes cuts down the tone alitle aswel.

Magnaflow
Dynomax Ultra flow
Borla
Are usualy pretty good.
Hooker has a few good mufflers aswell.

Kooks make really nice polished stainless mufflers that knock down noise, nice sound, no effect on my car at the track.
Pretty, and not expensive.


https://www.summitracing.com/parts/...G6tf39AIVahPUAR2RrQ-mEAQYAyABEgJKufD_BwE

These cut my noise down a little (with emphasis on “little”). Flowmaster FlowF/X 3” bullets.

I run 3” Ultra-flows on the street car. Noise level isn’t to bad. They are straight thru and stainless.
Doug

Dynomax bullet on my Challenger. They help quiet it down some. I mean a little, very little.

I like Pypes Race Pro. Quietest straight through muffler I've found. This is dual 3" with h-pipe and tailpipes.

https://www.youtube.com/watch?v=422uTiz78bs

SpinTech mufflers.

https://extrememufflers.com/ I use these mufflers in the square oval or what ever they call it. They sound on the deep side, but a bit loud. They are very light.

Borla XR1's

Do you know the weight on those kooks mufflers, was there any performance loss ?

No known performance loss. Not sure what they weigh. I have the 3 inch ones like i linked to. Guessing 4 or 5 pounds each. They are polished stainless.

Edit….4.33 pounds

I used a set of the older crimp style Magnaflow 14 inch long by 7 inch wide ovals with 3.0 inch side inlet with a perforated pipe exiting in the center. The muffs were mounted at the rear bumper and fed by 3.0 inch pipes off the 3.5 inch Hooker fenderwell A body headers, that car slowed down .03 ET in the 1/8 mile with them on and .2 MPH, 7.01 ET hooked up at 95.3 MPH, 6.98 ET at 95.5 MPH with the complete system removed
IHTHs
That car was a real hoot, not real loud at part throttle cruising but a lot louder at WOT
Best run with the exhaust system on in the1 /4 mile on Oregon pump swill was 9,994 ET at 134.6 MPH weighing 3450 Lbs. with me in it

At the end of your collecter, what ever length works best, go up an inch in diameter with an adapter , and add a straight through muffler of the larger size. Add an extension on to the muffler. As long as the system stays at least an inch bigger than the collector you have a zero loss system, except for the extra weight.

if using a complete exhaust system, [x pipe with tail pipes] would race bullets at the end of the tail pipes [where the gasses are the coolest] be the least restrictive place in the system to place them ?

[s][/s]

Performance matters less the further back you go on the exhaust system

Years ago my street car ran 11.72. It had 3” to the back bumper with Flowmasters. Removed the entire system (70lbs). Made a back to back run. It went 11.66
Doug

were the flowmasters in the normal position around the rear seat, or at the end of the tail pipes ?
some have suggested mounting the mufflers at the rear bumper.
i was wondering why ? better noise control ? less restriction because of the cooler exhaust gasses ? another reason ?

Engine Masters on MTOD did an episode on this.

The Dynomax UltraFlows performed really well and is what we have on the car.

3" pipe to the mufflers and 45* turn downs at the rear axle. Car is quiet enough to have a conversation in going down the road but has minimal restriction.

I have had issues with one that keeps cracking where they stamped "DYNOMAX" in it. We've had to weld that up a few times but it's just on the one muffler. Other than that minor issue, very pleased with them.

I remember Spiro Pappas' Camaro in old NMCA Super Street had Borla XR1 collector mufflers with 4" pipe to the rear axle. Was the quietest, best sounding exhaust I ever heard.