My nephew wants to delete the muffler from his 04 RX8 -- i.e. run with no pipe at all. This strikes me as a bad idea. I'm trying to convince him to at least straight pipe it. It already has no cat.

The way I see it, some of the "cons" of blowing exhaust under the car include exhaust gasses seeping into the cabin, and hot exhaust damaging underbody parts as well as underbody coatings meant to prevent rust and corrosion.

Additionally I read that an engine needs a certain amount of back pressure to run properly, but I don't know if that also applies to rotaries.

Help me build my case! Thanks.

 

Does he enjoy having hearing? Because uncorked rotaries are LOUD. More than your average Civic. Hearing damage after prolonged exposure kind of loud. Also there
is no power to be had from doing that... so the only point would be noise.

 

Deleting the exhaust is about the dumbest thing you can do on a NA rotary. He won't get a mile down the road before being pulled over.... All that being said, I would tell your nephew to do it....

 

He’ll be melting a lot things under the car dumping it there, maybe even the plastic fuel tank! There’s also the no-cat fumes smell and the safety aspect of the gases getting inside the cabin. It will also be twice as loud inside the car that way. And it’s not just the loud part that get’s you. There’s a frequency tone/ring to the exhaust under the car that starts to feel like a high frequency drill/spike in your brain when you’re cruising at the same speed for a while, like on a highway or interstate. So even the racers run it all the way out the back. People will hear it coming from several miles away.

it’s been done many times and always with regret. Including me for competition use 15 years ago.

Except there’s always that one occasional dum-dum that has no sense at all. He sounds like a candidate.
.

 

I cranked mine up w/out midpipe or muffler....just once... after my turbo install. Couldn't wait...to hear her purr...
Ma'aaaan, I couldn't get it shut off fast enough. Definitely talking hearing loss loud.

 

Basically, just pull up a video of 787B(yeah I know it's a 4-rotor, but it will do), then turn the volume up as high as you can on headphones, and have him listen to that non-stop for half an hour.

Now that I think of it, that sounds like some kind of interrogation/torture tactics.

 

I read somewhere about an old racer who had an rx3 or rx4 race car that had an open header actually caused metal fatigue cracks in the floorboard sheetmetal. The exhaust note of an open rotary is a Weapon of Mass Destruction.

 

Even Mazda race cars had pipes and they were still incredibly loud from what I understand.