Cosmo Kramer

Hello, I bought an aftermarket exhaust from the local Porsche dismantler, very nice condition. Installed no problem and sounds awesome expecially at higher rpms but below 3000 it's pretty droney. I didn't get any hardware with it so I just bolted it up straight to the transmission mount with the factory bolts. I am wondering if it was supposed to have some sort of a rubber mount to help with the droning.

I believe it is a Beluga Racing exhaust, I have attached a pic.

RonJo Crisman

I have the same one and it drones. They do not include any rubber mounts to reduce drone (at least mine didn't that I bought new) but I've certainly considered the same thing. Once my other projects are done, I'll have to give it a try!

Please do update if you decide to go that route. I wouldn't mind being rid of the drone despite all the other noise I've caused it to make installing a poly motor mount!

Cosmo Kramer

I slipped two 1/8" thick neoprene washers in between the mount and two on the bolt heads. No metal to metal contact, but the drone remains. I find it sounds ok when the exhaust is cold but when it gets hot its worse. I think the answer is either add a connecting pipe between the cans to cancel out the pulses at low rpm or slip some motorcycle baffles, unequal lengths in each side.

BoxsterSteve

I had a similar 2-can muffler on my car when I bought it.
The drone comes with the territory, I'm afraid. Loved the volume, but hated the resonance.
Replaced mine with a Crios modded factory unit I picked up for nada.

Cosmo Kramer

I am contemplating trying these, read some reviews online and they seem to really work. Could even make them yourself.

http://synapseengineering.com/products/nodrone.html

10/10ths

The factory muffler design is part of the entire powertrain NVH balance. The muffler acts as a harmonic balancer, so to speak, and any aftermarket twin muffler design that gets rid of the one big can attached to the factory attachment points WILL introduce drone....Period.

RBatsch

Recent tech night at the local Porsche dealer we had access to some Porsche Technicians and they all warned about aftermarket exhausts. Namely the big issue is that the pipe going over the rear axles on the Porsche units are insulated and aftermarket are not. They cautioned us about heat damage to the body of the car (sealed seams and such). We also had an owner with a Fabspeed exhaust where his rear bumper had begun to melt at the exhaust tips. Aftermarket is no longer on my to do list!

Cosmo Kramer

Well I decided to play fabricator. I made two baffles, one 3" and one 4". I used a small piece of 1 3/4 ID tubing, two flat washers and two steel 3/4" pieces of steel pipe. I drilled the washers and pipe with 5/16 holes then welded everything together. Slipped them about 1 1/2" into each tail pipe and locked them in with a sheet metal screw.

Drone has been reduced by at least 60% it's still there a bit but totally fine and almost unnoticeable with the top down. Exhaust has a bit higher pitch and raspy note to it now. The seat of the pants dyno says no power loss. Total cost was $15 and some quality time in the garage.