I am getting to the point in my 4.9L build where I have to start considering which muffler and catalytic converter combination will give a great sound, without breaking the bank or robbing too much power. I do require a catalytic converter due to emission requirements. As such I have made the decision to use the stock locations for both the muffler and cat. The manifolds will connect with a Y-pipe forward of the engine. I want to use a single crossflow muffler with dual outlets. (2 1/2" pipes). I want a great V8 sound, just not too excessive in the volume...

What muffler and cat do people recommend? If people could post videos with their setups so I can hear the sound that would awesome too!

(Didn't want to fill up my build thread with this question... https://www.fiero.nl/forum/Forum2/HTML/129733.html )

Transverse mufflers. I have the Afterburner on my Indy.
Loud as hell without a cat. convertor. Better with one.

Don't know of anyone with the Full Boar muffler yet.
I just came across that one recently. There some YouTube videos.

https://www.fiero.nl/forum/Forum2/HTML/131937.html


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[This message has been edited by fierosound (edited 03-08-2014).]

A lot of people comment positively on the sound of the Flowmaster 80 in my 4.9 Formula. Fitment with an under engine exhaust may be problematic.

I can't really suggest that it would sound good with a 4.9... but I imagine it would.



Spintech "3800sc" muffler, magnaflow high flow cat.

[This message has been edited by mitchjl22 (edited 03-08-2014).]

quote Originally posted by mitchjl22: I can't really suggest that it would sound good with a 4.9... but I imagine it would. Spintech "3800sc" muffler, magnaflow high flow cat.

It does! I had a Flowmaster 80 series for a little while and then switched to a Spintech and liked it much better. To me it sounded smoother and higher pitched. Here is a comparison, keep in mind these are both without catalytic converters and terrible quality videos.

Flowmaster:


Spintech:

quote Originally posted by Zac88GT: It does! I had a Flowmaster 80 series for a little while and then switched to a Spintech and liked it much better. To me it sounded smoother and higher pitched. Here is a comparison, keep in mind these are both without catalytic converters and terrible quality videos. Flowmaster: Spintech:

Based on your videos, I actually like the sound of the Flowmaster 80 a bit more. Wonder how it would sound with the Magnaflow high flow cat

I wouldn't use the 3800 to guage the sound of a 4.9 application. Quite frankly the 4.9 sounds so much better right out of the box.

I used the 93 Deville exhaust manifolds which have a down spout out the rear set. I ran a simple 2.5" pipe down to a T and then added CATs on either side into custom Spintechs.

The Spintech guys made me up a pair of 12"x7" with diagonal intake and center out. The setup has a deep round full thump to it and is not too loud for the gendarmes.

The downside is that you have to cut back the channel in the bumper on each side a bit to fit them, and if you don't like a "square" muffler showing, don't buy them.

They are really heavily built and will outlast the car. They sound awesome. I have nice chrome Magnaflow tips, for dress up.

You could run a muffler with a center in and two outs, but I didn't do it that way because, while we don't test for emissions on old cars in my jurisdiction, you are required to have a CAT if the car came with one. Hope this helps

Arn

Edit, you really want solid engine mounts with my setup or the metal in the exhaust will fail due to flexing, or you can put in expansion panels

[This message has been edited by Arns85GT (edited 03-08-2014).]