I know that it is a common problem with aftermarket exhaust. I have an 08MCS with a stratmosphere exhaust. It makes awesome music above 3500 rpm, and has a nice burble at idle, and sounds stock cruising from 40-65mph. Above about 2300 rpm on cruise, or during light accelleration the car is an echo chamber.

This exhaust is a 2.75" pipe, no cat, no resonator, and a bullet type muffler in the stock location. I'm running the stock downpipe.

I thought I remembered seeing pics of someone that made a stand-pipe in the straight section. I couldnt find that thread. It was a second pipe, welded in place, parallel with the actual exhaust. The second pipe was capped off, just adding volume to the exhaust.

Is this a reasonable option compared to adding a resonator back into the system? Any other ideas?

Mike

 

You can not go wrong with Vibrant
http://vibrantperformance.com/catalo...1022_1033_1054

That is what you need there to quiet down the drone.
Just noticed they didn't have 2 3/4 so you might want to get some adapters to 3".

Typically the longer the better(that's what she said). It normally helps take out the reverberations that cause drone.

 

I put in a 4x18 resonator in the system, and it did what I wanted. Drone is still there, but not obtrusive, and the sweet sounds above 3500 rpm still exist.

Mike

 

You could just buy a good exhaust... The Invieda droned like hell. It about made me deaf on a trip to NJ...I've ridden in a car with an Akropovic and there was none. But at almost $1800 there better not be. I picked up an entire JCW (dp back) for cheap and it's louder than stock, but no drone...

 

This is a pretty common problem among various car lines. Like you say, most of the time you get what you pay for, but not always. I was watching for a JCW exhaust, but the only one that I saw come up was taken by someone about an hour before I got to it. Glad you like it....

and I'm glad that I found a solution for my car. For $85 it is an option to guys that have a droning problem.

Have fun,
Mike

 

Okay so I will say it again, if you can't handle drone then you don't need to get an aftermarket exhaust. There is also no way I would pay $1800 for an exhaust. It better be full Titanium. I love my Invidia, I don't know what drone you are talking about considering I am running a full turbo back. It is a little loud but on the highway I have more road noise than exhaust noise. I am probably going to go to a larger exhaust though.

 

Porthos is correct. I have an Akrapovic DP and a VIP Custom DP-back. I LOVE the sound... Others LOVE the sound. What's the difference between the VIP Custom and Akrapovic DP-backs? Besides $1000, they both have resonators and are tig welded and mandrel bent 304 SS. Some say the drone comes from the DP. I have drone 85+ mph going up hills that makes you want to open the window to relieve the pressure on the ear-drums... Is it the DP or the DP back pipe that has the same specs as the expensive Akrapovic version. As Porthos says: "if you can't handle drone then you don't need to get an aftermarket exhaust."

 

Crap...now I'm torn if I should use a 12" or 18" resonator to quiet down the vibration and loud drone on the highway lol. Probably go with the 18" then...

 

the best way to get rid of drone is a resonator. i did not have any resonators (or a cat, just a straight turboback) on my last track toy, and cruising at 2500-3k rpms was, well, almost intolerable. hubby had a 18" resonator on his car and it made such a difference, i almost put one on myself......almost lol. they really do work, and quite well.

 

Did you lose the loud deep sound when getting on it though? I'm putting one on today but trying to figure if a 12" or 18" is better. Thanks.

 

It still sounded throaty at wot, just not annoying. If it quieted down our cars, I'm sure it will work wonders on a mini. As to your issue, a 12" will probably be fine, but the 18" will really help cut the drone and makes the car quieter overall. I don't mind the noise (hence why my car never got a resonator) so I would go for the 12" personally. Normal people would probably go 18" lol!

 

That's awesome, I need to find a girl who doesn't mind drone. I used to have a stock setup with resonator delete and girls would complain it was too noisy when they say in it. Now I'm running a turboback with no resonator and it feels like my ears are gonna blow up, but I'm really enjoying it.

 

Just go with an 18". It will be quiet at cruising speed but it will still have a nice sound at WOT and that is all you need

 

Or try this!



Helmholtz resonator!

 

Put an 18" resonator on. It helped a little bit. But I think the exhaust still needs to be broken in so I can get my final result. But still sounds good:-).

 

Interesting update:

About 2 weeks ago I put on a FMIC and NM hot and cold pipes (don't lecture me on the pipes, I got a good deal...). The drone came back. I guess that it shows me that it is a system, and changing any part of the system must have an effect.

I see a few options:

1. Put the MCS exhaust back on, and lose the nice sounds
2. Remove the resonator, see if the system changes made the drone different
3. Quityerbitchin and deal with it.
4. Try a JCW exhaust with the factory resonator.
5. Pick up a DP and run it with the MCS exhaust (will this make me fail smog test?)

Hmmm, lots to think about....

Mike

 

option 3 haha. i have a full 3 inch exhaust with no resonator or cat. just a magnaflow muffler. its loud and i love it!

 

im just messing around by the way, i hope you get it all figured out.

 

Option 6.

Go 2.5" all the way, add a couple of Helmholtz chambers with a Flowmaster Hushpower dBx muffler to kill the drone.


These are the lessons learned trying to kill the drone. This worked!!

 

Scott,
Can you describe your chamber development? It looks like you have about a 2" pipe that you fishmouthed into your 2.5" main pipe. Did you just keep trimming the length until you got the result that you wanted?

Thanks for any advice.

Mike

 

There are actually two Helmholtz chambers. The first one is the rectangle unit forward of the crossover support. That's a 12 inch chamber (14" total length) developed my Flowmaster. It reduced some drone but not enough. The second unit is a 28" long Helmholtz chamber. It killed more than half of the remaining drone making Louise comfortable to motor in.

Yes it was some trial and error to get it right but prior to adding the Helmholtz chambers the drone was painfully deafening.....

All of the exhaust work was done in stainless and painted black, because I like..... black.