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I was wondering if a set of Flowmaster Super HP-2 mufflers into a pair of exhaust tips could replace the axle back. Instead of routing the current way, it'd be a straight shot to the tips. Is there enough room?
Maybe, you will have to contend with the rear trunk storage area having it a straight shot out the rear bumper.
Get the muffler dimensions and cut it out of cardboard to mock them up under the trunk area to check initial fitment. You will need the rest of the catback piping custom built.
When the Mallett modified C5's were tested by C&D IIRC, it turned out they had a "straight" exhaust run. Mallett also had a template of how to cut and rework the center storage compartment to accommodate the mufflers.
I'm going to say no without cutting the rear compartment and/or custom over axle pipes. I took the muffler sections off of my Corsa Sport a couple months ago and slapped some turn downs on to the end of the over axle pipes. Eyeballing it, a straight pipe coming straight out would be super tight if not impossible. Something thicker, like a muffler, would be a no-go.
I have dual Flowmaster mufflers I got at Summit years ago. They were pricey ($250.00/each!), but sound great. They do drone slightly at freeway speeds, though. They are C5 specific, and look almost identical to the OEM mufflers, except the dual outlet pipes are at least 1/8" larger, the tips are slightly different, and they have a deep, throaty sound. NOT a Cat back-You must cut off your old mufflers, and then mount these. They mount in the same rubber isolater mounts the OEMs do, with a tang that slides into the rubber mount. I don't know if they're still made. They are pricey for 2 mufflers, and I've never seen another set on a C5......
Last edited by grinder11; Dec 14, 2022 at 07:49 AM.
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Originally Posted by heggsc5
I'm going to say no without cutting the rear compartment and/or custom over axle pipes. I took the muffler sections off of my Corsa Sport a couple months ago and slapped some turn downs on to the end of the over axle pipes. Eyeballing it, a straight pipe coming straight out would be super tight if not impossible. Something thicker, like a muffler, would be a no-go.
Thinking about what you want to do, I would have to agree with this. The center storage compartment is going to be the issue as well as having enough room over the axles for some custom work.
Routing straight back from the h-pipe is certainly possible without modifying the storage compartment, but yes, the issue for this scenario would be the mufflers. With the body of those being 12" long, you would definitely have to get creative and likely modify the compartment to clear them.
Borla's XR-1 system follows the general route you've indicated wanting to attempt without requiring any modifications, so you can see here the general bends they use. Of course this is without the bulkier mufflers. Hope it helps in some way for reference!
-Nick
Last edited by Mid America Motorworks; Dec 14, 2022 at 12:17 PM.
Reason: Typo
I crawled under one of our C5s here to take some measurements based off the specs of those mufflers. You would absolutely have to modify that storage compartment to be able to make them fit and have the tips in a presentable alignment out the back. Without modifying the compartment, those tips would be drastically angled down towards the ground and the mufflers would likely rest up against the compartment and rattle, not to mention the heat.
I'm late to the party, but I have a Magnaflow set that has mufflers at the front instead of the back. I had to get them because of the rear bumper I have. When I bought mine they were dual tips and I ended up changing them to quads. It looks like they come as quads now. They are pretty loud on the outside, it's not too bad on the inside on mine, but I have my car dyno matted.
Think this exhaust would work?
