2023 NA muffler

[2.7RS]

I have a 1985 NA track car that I want to start driving to the track. Not trailering.

Car has headers and 3 inch pipe that ends in a horrible loud magnaflow muffler.

I just want to make the car quieter and more enjoyable on 2 hr drive.

Any suggestions for a 3 inch diameter muffler?

Thank you

[walfreyydo]

Im using this on my 3" setup. It wont drastically make the car quieter but it does reduce the drone quite a bit, especially if you add stainless steel wool wrapped between the baffles.

Its pretty easy to remove if you have the ability. You could put it in the test pipe section right after the connection to the exhaust/header downpipe

https://www.carchemistry.com/baffle/

See this thread for my 3" exhaust build. If you do go with a muffler, I highly recommend getting something that is NOT "straight through" design as it wont reduce sound to any real degree (one of the mistakes I made when building my setup). The biggest improvement the above baffles will give you is a reduction in "drone" at highway speeds.

There is also a video at the end of the thread to hear how it sounds with the above baffle in place. (I used the cap and stainless steel wool to increase sound reduction)

[2.7RS]

That is a sweet exhaust you built.

I tried baffles and still loud on a long trip.

Really looking for a muffler. I should probably try a chamber muffler with some offset as supposed to a center straight one.

Thank you

[walfreyydo]

Yeah the offsets are the ones that are chambered, the center in/outs are usually straight through

[wildcat077]

My SP2 car has a Stahl header and 2.5 dia stainless exaust straight through the back, last year they imposed a 93db sound level at Circuit Mont Tremblant and i had to install a muffler and the muffler that passed the sound test was a Thrush model 177715, it's a center in , offset out but you can interchange the ends.Originally when i bought the car it had a MSDS header with a Hooker Aerochamber 3 inch dia exaust as recommend by Karl Poetl.
Anyhow , you can look in to the Hooker header, it's not restrictive as far as power goes and it would be perfect for the street.
For what it's worth , the Magnaflow muffler that the shop supplied when they did my new exaust was like running no muffler at all ...

[v2rocket_aka944]

I have a Dynomax super Turbo muffler on my V6-swapped 944. it cut the volume level considerably over the magnaflow i had on there previously.

FWIW i only use a 2.5" system for this 3.9L engine, i don't really believe a 944 needs a 3" system without a turbo.

back in the day when i did a lot of 944 mods and dyno testing i still got 136whp on 91 octane through a 2" exhaust with a cat and stock muffler.

the 3" magnaflow you have currently, is it an oval body or round body? i have been thinking about adding a round body MF to the center of my car to quiet it down a little more.

[2.7RS]

Its a 3" diameter center round pipe. And short 10 or 11 inches.

I think if I can find a muffler that extends closer to the bumper it's going to give more "muffleness"

Thank you

[2.7RS]

Just google the dynomax super turbo.

Offset inlet/outlet that should help.

For the price I'm going to try it

[2.7RS]

What I learned

3 inch center resonator from vibrant made a big difference in internal drone. Kept it

All 14 inch long muffler that fit in the factory space. Measurements with phone app 4000 rpm in the driveway


Magnaflow Dynomax and Borla xs mufflers too loud also very light in weight between 90 and 95 db.

Spintech 3000 less loud heavy, thick steel 85 db. Kept it


Car is still loud, because of cams, high compression pistons, stepped headers, and 3 inch pipe idles loud, by no means is quiet

But now I can drive it to the track and is not as bad while driving in town