GlenL

I recently replaced that unsightly center section of the exhaust system with a bullet "Glass pack" muffler. The exhaust had broken and needed some work.

The pipes on my '87 NA are, surprisingly, standard US 2 1/4 OD. I sawed out the bulgy "Cat" thingy and mounted in a 20" body (25" overall) with 2 1/4" ID ends Thrush muffler. At the front there's not much tube to work with and the hanger is close. Cut leaving as much length as possible and then file off any weld drops on the outside.

I could have used the 22" (27" overall) muffler for a little more overlap on the tubes. Took some gentle persuation to get it together and the fit is snug. Clamped it down and it sounds great. A bit more power, perhaps, in the 5700-6500 RPM range. It's fun.

Dougs951S

My NA still has stock exhaust with a cat, im going to replace the cat with a 2.25" straight pipe and then replace the stock muffler with a thrush single chamber.

admiralkhole

We should experiment with your car...

http://www.ebay.com/itm/Dynomax-2423...f11a1c&vxp=mtr

...you know how good my car sounds with a dynomax

yeah yeah I know about the 4 extra cylinders, that's besides the point.

rsabeebe

so, you're running a Bullet glass pack AND a 20" Thrush muffler? it would seem to me, even with flow-through designs, that would be on the quiet side. i have a Bullet muffler to install on my 951, when i get to that point, but i have no firsthand experience with the product line. my cat was replaced with a test-pipe (with wastegate tie-in), so i'm hoping it breathes quite a bit easier after the install.

GlenL

It's still got the stock muffler at the back with a bullet-style glass pack in place of the cat. I had read somewhere that a straight pipe in the middle makes the car sound funny; harsh or something.

I was showing it to a friend who has a '87 924S and he thought is sounded great. A bit deeper and throatier.

If I ever get around to doing a dyno test I'll post it.

dirtyTurbo

You're going to regret doing that. I have one of those in place of my cat, and with no muffler it's stupid loud.

admiralkhole

You want a resonator where the cat is, then a nice muffler out back. Sounds much better.

odonnell

My car has late headers, resonator in place of cat, and a thrush welded muffler. It sounds pretty burly at low revs and sounds aggressive without being too ricey over 3000, welded up to my exhaust by Mr. Admiralkhole himself. Dougs951S may or may not be trying to replicate it

Dougs951S

You're saying stick that in place of the cat and run a 2 chamber thrush out back? That aught to sound nice, I'm not looking for the same level of loud in this car as my 951, being able to hold a conversation inside the car with the windows closed is a requirement.

admiralkhole

No, I'm saying run a resonator where the cat is and run this or a different muffler where the stock one is. I really like the short bullet straight through muffler sounds...they seem to shape the sound nicely.

Dougs951S

Gotcha, I thought that dynomax unit you linked to was a resonator/cat replacement, didn't realize it was actually a muffler. They DO sound nice and I will definitely run a resonator vs a straight pipe in place of the cat, but I'm worried even with a resonator that the straight through muffler will be too loud. It will be louder than michael's car, probably not as loud ad my 951, but who knows. Its hard to make a fair comparison since my N/A still has all the factory insulation and sound deadening and the 951 is mostly stripped.


We could try running two of those and seeing how that sounded, one in place of that cat and one at the end. I bet it would sound good and not be too loud.

JJR512

I just saw your video on YouTube where you're going up and down a street to show off your exhaust sound. Can you tell me exactly what parts you're using?

odonnell

Mine may be slightly different but IIRC this is the one:

http://www.jegs.com/i/Dynomax/289/17...oductId=763864

The video was shot with a phone, it sounds less raspy (better) in reality.

Unsure of the resonator model, it was in place when I bought the car. The cat is gone and the resonator is welded in where it used to be.

GlenL

For reference, I used this Thrush 24201 at O'Reily:

http://www.oreillyauto.com/site/c/de...0895&ppt=C0112

I'd suggest a bit longer 24203:

http://www.oreillyauto.com/site/c/de...0895&ppt=C0112

Twp clamps or weld it. I would add to get the doughnut seal for between the front and rear sections in advance.

JJR512

How is the volume level? Just asking because if I understand correctly, you're using two mufflers...the Thrush glass pack in place of the cat, plus the stock muffler.