best quiet muffler for a 9 second car - 4" single shot

[rwrows]

My car has a 4" single shot exhaust with a 4" bullet type muffler (about 12" long or so) close to the downpipe. It's way too loud for me. I'm looking to add a quiet muffer towards the back of the car. I'm looking for suggestions for a muffer that will be as quiet as possible but won't hurt the spool. Thanks!

 

[Squid4life]

This is what I plan to run on my dual 3" on the race car:
http://www.summitracing.com/parts/WLK-17557/

I think it was charlie posted a pic of someone who did testing on a bunch of 2 1/2" muffs on a flowbench, comparing open pipe to muffler & flow, plus dB level at 750, 2,000 and 5,000 rpm and IIRC the Dynomax Ultraflows were the best. Flowed like 97-101% and had the same dB rating as the other muffs. I will see if I can dig it up...

 

[Roger]

Cadillac is quiet & they run a single to the axle & split to duals with muffs just ahead of the bumper. Unfortunately I don't know how well they flow.

Seems the quieter setups have the muffs as close to the outlet as possible. Might try an exhaust tip muffler.

Some 9 second cars use a 3 muffler setup, one is a crossflow.

 

[turbofabricator]

On Dennis' race car he ran three 3" mufflers. Two Ultra-flows in the normal position (in front of the 4-link) and a modified ATR 3" cross-flow behind the rear axle. The cross flow muyffler is the key to being quiet. He ran 9.16 @149. On the chassis dyno it picked up only 7 (seven) HP un-capping the system. There is no way to quiet a 4" single system. Look into the "3 muffler" thread to see how it is made. http://www.turbobuick.com/forums/threads/3-mufflers-for-a-quiet-system.167389/ Kinda involved, but WELL worth it if you really want to make your car enjoyable to drive (with out ear plugs).

 

[bison]

I have yet to see a muffler that flows like an open ex be quiet. A true muffler will hurt spool and power a little. Run one and open your ex when you want the best flow

 

[turbofabricator]

I have yet to see a muffler that flows like an open ex be quiet. A true muffler will hurt spool and power a little. Run one and open your ex when you want the best flow

Try the three muffler system sometime. You WILL be amazed. Dennis has run 10.03@136+ thorugh a 2.5" system. Church mouse quiet at idle and cruise, with ZERO drone. I just wish a vendor would step up and offer it. That way I won't have to hand fabricate it outta U-bends. Anyone??....Anyone?........Bueller?.....

 

[JP112_89]

I have the 4" Mufflex , Magnaflow straight thru muffler/catback. Not sure if there is anyway to quiet it down.lol I seen a guy with a 3rd gen t/a with the same exhaust. He put another straight thru muffler in place of the test pipe.haha So he had two mufflers. Not sure what it sounded like I don't even know if I should have posted this.lol

 

[ttypewhite]

4" and quiet does not exist. Your gonna have to add a couple resonators on it to tone it down. But your quest for a quieter system is going to add a good amount of weight to the car. I love my RJC 4" with a single Borla muffler. A bit load at initial take off (just the way I like it) but nice while cruising.

 

[charlief1]

Here's the muffler comparison James mentioned earlier. It might help you decide on a good one for flow purposes.

 

[Squid4life]

Here's the muffler comparison James mentioned earlier. It might help you decide on a good one for flow purposes.

There we go! I was pretty sure that was you. I have used the heck out of that chart recently. I just wish we had something in 3", but I would imagine similarities between 2.5 and 3".

 

[charlief1]

There we go! I was pretty sure that was you. I have used the heck out of that chart recently. I just wish we had something in 3", but I would imagine similarities between 2.5 and 3".

You and me both James. I had one before the the puter crashed and I haven't found it yet. This one was posted by Mr Wood some time ago and I know there's one for the 3" and larger but I've yet to find it.

 

[bison]

Try the three muffler system sometime. You WILL be amazed. Dennis has run 10.03@136+ thorugh a 2.5" system. Church mouse quiet at idle and cruise, with ZERO drone. I just wish a vendor would step up and offer it. That way I won't have to hand fabricate it outta U-bends. Anyone??....Anyone?........Bueller?.....

The last thing I'm going to do is waste more time and add weight to the car. It's got 800hp. I don't really care that it's not too quiet. I'm sure that three muffler setup helps a lot. Post pics

 

[rpoL98]

i've also got a 4" single shot exhaust with the muffler in that recess under the pass side back seat. it doesn't quite meet my expectation of the "going fast with class" motto, interior noise/resonance at cruise speed. i gotta redo the test pipe anyways to meet up with the newly installed 4" cat back, so am looking at what muffler would fit where the cat converter used to be, to mate with my 3" downpipe. don't want it to be hanging too low, since i went to a lot of trouble to tuck the humongo 4" pipe, muffler up real close to the floor boards, driveshaft tunnel.

it will be something that's short, oval, glass-packed, straight-through, with a stainless case... likely magnaflow or borla.

 

[turbofabricator]

i've also got a 4" single shot exhaust with the muffler in that recess under the pass side back seat. it doesn't quite meet my expectation of the "going fast with class" motto, interior noise/resonance at cruise speed. i gotta redo the test pipe anyways to meet up with the newly installed 4" cat back, so am looking at what muffler would fit where the cat converter used to be, to mate with my 3" downpipe. don't want it to be hanging too low, since i went to a lot of trouble to tuck the humongo 4" pipe, muffler up real close to the floor boards, driveshaft tunnel.

it will be something that's short, oval, glass-packed, straight-through, with a stainless case... likely magnaflow or borla.

Sorry, but installing a muffler in the "cat location" will do almost nothing. Seriously.......I have tried just about everything to quiet the drone down. Only a cross flow muffler in the stock muffler location will accomplish that. (besides installing a cat converter.) Go back and read the three muffler post and see all that I have tried over the last 25 years to make these cars FAST and quiet. We've run 9.1's @149 with three mufflers (in 3") and 10.03 @136+ with three 2.5" mufflers.

 

[turbofabricator]

But to answer your question.......you can use a 3" Ultra-Flow round muffler in place of the cat.

 

["Turbo-T"]

Only a cross flow muffler in the stock muffler location will accomplish that. (besides installing a cat converter.)

Not to go off topic but to ask...suppose you have a straight shot system and you add a cat...how much drone would it take out?

 

[Pronto]

It won't drone, it will meow.

 

["Turbo-T"]

It won't drone, it will meow.

LOL

 

[Razor]

Whats a muffler?

 

[turbofabricator]

Whats a muffler?

They look like a big metal can. They go on the exhaust pipe. They are usually under the car, but are sometimes on top of a tractor. They come in many many different designs. The are usually filled with ear plugs. I think so anyway. Some have more ear plugs in them than others. That's what makes them quiet. If you really want to make good power you need to look into the world famous Bubb Rubb whistle tip muffler. Man.....those things really wake a car up. (and your neighbors, too). Julio.......I hope this helps. That pretty much "exhausts" my muffler knowledge.