[NRG x Mpower]

*** sorry - posted in NA cars... hope they can remove that one ***

hey guys,

i installed a few months back a quad exhaust setup on an AT 335i. and while it was cool for the first week or so... the excitement has worn off since then... and now just replaced by annoyance.

the car has a nasty drone... the car's cruising speed (on FWY's) is just slightly above reasonable. plus there's random buzzing/noises from all the ash tray doors, covers, etc in the rear seat area....

so here's my question:

a) do i go back to stock, and just install CYBA quad tips? and lose the exhaust note all together? (cause from the outside - the car sounds GREAT!)

b) if i dynamat the trunk space, rear seats - will is muffle and suppress the cabin noise enough?

don't get me wrong - i love my exhaust sound - makes the car aggressive sounding... but hate that it sounds so loud inside...

[Bakeme521]

I can't think of anything else you could do to help it besides change the exhaust. So I guess what I'm trying to say is give the dynamat a shot and see what happens? Can't think of what else to do.

[NRG x Mpower]

yeah... not sure if i should DYNAMAT it or just go to stock exhaust + cyba tips

[TMR]

Id say replace the exhaust system with something that is not so loud in the car.

[TurboBimmer]

The Bmw Performance exhaust sounds great with next to no drone. For looks you can add the Cyba tips.

[Jonny550]

DYNAMAT is something those guy in the older carbureted big blocks use. Just becuase of the fact that all they had back then were straight pipes and why would you wanna take away any of that pretty sound so just throw in some dynamat.


They say it reduces drone 50% witch sounds pretty good to me. I would put some in the trunk underneath the lines just to see how it sounds and if you still dont like it go with some different mufflers.

[GotBoost?]

i ran DYNAMAT in my fully catless 06 mustang with SLP proflows and it really did help alot.. it just weights a ton...

[IlChengis]

Dynamat weight would be my concern. Besides performance, the other reason I am keeping my aftermarket exhaust despite increased noise and vibration is weight. I could not believe how heavy the stock unit was.

I have similar issues and I've heard that a small folded towel or tennis ball inside the tray door in the rear seat area fixes that issue. Have yet to try it though.

Good luck,

-Walter

[Proper Motion LLC]

Try adding a h-pipe and resonators

[NRG x Mpower]

Originally Posted by IlChengis

Dynamat weight would be my concern. Besides performance, the other reason I am keeping my aftermarket exhaust despite increased noise and vibration is weight. I could not believe how heavy the stock unit was.

I have similar issues and I've heard that a small folded towel or tennis ball inside the tray door in the rear seat area fixes that issue. Have yet to try it though.

Good luck,

-Walter

HAHAHA... i did the SAME thing... i crammed a microfiber towel in the storage drawer thing in the center back seat, and few other crap in the rear ash tray door. LOL!

[Tee212]

stock exh sounds best inside n out lol

[bimmerboy]

dynamat should help a lot, if you want a cheaper alternative look for "peel n seal" .... Sold at Lowes for $14 a roll, works wonders for sound deadening

[IlChengis]

Originally Posted by nrg x e92

HAHAHA... i did the SAME thing... i crammed a microfiber towel in the storage drawer thing in the center back seat, and few other crap in the rear ash tray door. LOL!

So it does work?

Originally Posted by bimmerboy

if you want a cheaper alternative look for "peel n seal" .... Sold at Lowes for $14 a roll, works wonders for sound deadening

Good to know... thanks.
I might try that in my Civic. It's the CX model (hatchback) and it came with no sound deadening. Light but noisy.

-Walter

[n3985]

Dynamat and equivalent does NOT help much from personal experience. On another car I had the entire trunk floor, rear deck, and trunk lid insulated with two layers of sound deadener PLUS a layer noise barrier. Result? ~10% reduction in noise....

[NRG x Mpower]

yeah man... it's these really VARYING responses as to how much noise reductions are happening with the materials that worries me... the cost of the DYNAMAT is about same as me paying to buy new CYBA tips for my stock exhaust.

[Car Enthusiast]

Yeah, the rattling/buzzing sounds from the rear seat area of my car were really annoying to me too after I got an exhaust. I did what others have suggested and stuffed a couple tennis balls into the rear storage area and closed the top. This really worked well in reducing the rattling/buzzing sounds by about 80%.

[dzenno]

no rattles/excessive noise with the AE catless exhaust here...i guess its due to built-in resonators...

[eseng]

I have similar issues and I've heard that a small folded towel or tennis ball inside the tray door in the rear seat area fixes that issue. Have yet to try it though.

[/QUOTE]

+1 ive done this and the buzzing will usually go away after that and u'll get use to the sound in no time.

[tahoerdr]

"Brown Bread" is a cheaper alternative to Dynamat, nearly identical but slightly better sound deadening properties. I used it in a 4runner with a droning exhaust (2 layers + 1/4" rubber pad) to significantly reduce drone. I'm going to put 2 layers in my trunk & under rear seats within a month or two, I'll get back on how much it helps.

http://www.b-quiet.com/

[XS4]

Don't waste your time on Dynamat. Get another exhaust. I say this from experience. The earlier poster was right - I did the entire back half of a previous car trying to reduce the drone from a borla exhaust. Added about 50 lbs to the car and cost me about $300 IIRC and countless uncomfortable hours pulling up upholstery and wires, cutting it to fit and burnishing it down with a spoon. About 10% better and not in the frequency I needed. Filling up the trunk with a super bulky blanket does a better job (try it). Dynamat works great for attenuating vibration of body panels and making a good sound stage but it does not seem to faze low frequency drone.

[NRG x Mpower]

anyone know a good shop/audio shop - that can do dynamat or alternative installs in orange county?

[balance]

yup. Gold Star Audio in Irvine. should be real close to you since your in newport. they do great work and are very clean and professional. and looks like you have your own personal dealership lol awesome. i'm guessing you have one of those big 10 car garages.

and cheapest most easiest solution to get rid of that annoying drone on automatic transmissions would be to put the car in DS mode at freeway speeds.