smlporsche

I have a 3" exhaust w/o a cat and a Magnaflow muffler.

Last year I got black flagged at Road Atlanta and a couple of the tracks I want to go to this year have noise level restrictions.

What can I do short of completely replacing the entire exhaust to lower the dB levels and at the same time minimize any power reductions?

chrisp

get a set of Supertrapp plates and weld them to off-the-shelf pipe that fits over your exhaust outlet. It takes two seconds to put on & take off and can drop the noise significantly. I have a dual outlet race muffler that blows 96dB without and 89dB with the tips.

smlporsche

Chris-

Is this what you're referring to?

http://store.summitracing.com/largei...344-3004_w.jpg

It looks like this may be the whole system that would just attach with a set of clamps.

LVDell

Dumb question, but if you are getting black flagged at RA for noise, then what the hell do the race teams do?

Bull

No experience with RA, but many "noise controlled" tracks have a certain number of "unmuffled" days allowed (usually negotiated with some local Government), which they use for events where they can collect a large gate from spectators. Tracks like Lime Rock guard them very closely, and if they are found not enforcing the sound restrictions on a Club day, they can be charged with one of their "unmuffled" days as a punishment.

FredC

That is the case with RA.

LVDell

Amazing that there exists something like this. It's like living near an airport. You are going to hear the planes. Don't buy a place near a track if you don't like the sound of cars in the distance. I guess I am just lucky to have VIR as my home track and never have to worry about it. Well, we do have "quiet hour" on Sunday.

Bull

I agree. I'm luck enough to have a number of tracks close enough that don't have sound restrictions, and I consider VIR at 8 hours "close enough". I may do Calabogie for the first time this year (NNJR is doing Mosport and Calabogie back-to-back for 5 days), so I guess I will need to hunt up the muffler for the Cup.

LVDell

There's 50# I don't miss

Chris L.

The only good thing going for VIR is that Danville is NOT Atlanta. RA once was in the middle of no where just as VIR is now. Atlanta and it's suburbs just grew around it. Happens all the time.

smlporsche

A little background.
Last fall was my first time to RA and the first time running with this club and as such I was put in the Blue run group.
They assumed the the 2 slowest groups (Green & Blue) were primarily made up of street cars and would be the quietest so they scheduled them to run Sunday morning during church hours. Per club rules I was not allowed to get a checkoff ride until Sunday and it was during this checkoff ride that I was black flagged.
This fall I'll be in Black so this should not be a problem.
I noticed that my first event this year is at Roebling Road and in reviewing the info sent me noticed a noise restriction there...although I ran there last year w/o any problem.

Just trying to be proactive.

stownsen914

I have exactly this issue at Lime Rock with a 914/6 track car.

Supertrapps can be a good solution to quiet down a car, and you can't beat the convenience. Careful, though, as if you try to quiet the car by more than a few db with Supertrapp plates, it will essentially cork up your exhaust and make the car run like crap. Personally I was not able to get a muffler from 95 db down to 90 (LRP limit) without making the engine run like garbage (adjusting the fuel enrichment didn't fix it).

Another thing you can do if you're right on the limit threshold is to keep a clamp-on exhaust "turndown" with your collection of spares that you carry to the track. A turndown is just a 90 degree bend in whatever size tubing can easily clamp onto your tailpipe. This will only make a 1-2 db difference, but can be difference between running or parking it during a trackday.

Good luck!

chrisp

This is what i have with a short piece of exhaust tubing welded to it. I can't tell if the one you link to allows for plates to be removed/added.
http://store.summitracing.com/partde...5&autoview=sku

chrisp

the one I linked to is a 2.5" inlet. They make a 3" inlet as well (at the top of Summit's page). The 3" has a shield around it, mine doesn't. It can probably be removed.

RedlineMan

Hey;

Part of me is happy that there are noise restrictions popping up. I am not a fan of gratuitous noise, and there are always cars/drivers that fall into that catagory. A race car is one thing, particularly if it is a factory built car. Just pounding around in wanna-be mode... what's yur point? Having a loud car and a few extra HP doesn't make you drive better.

Anyway, to make a car as quiet as possible, and beyond having a quiet muffler, it needs to be as close to the end of the system as possible. Any free tailpipe length at all will begin to re-magnify the sound again. The proper tip for the application can also make a surprising difference

I've been playing this game for a couple of years. I have a side exhaust that exits right under the passenger window. I had the innexpensive Magnaflow straight through SS can. Really pretty, but WAAAAY too loud. Next came one from Stainlessworks. Quieter, but still too loud. I then got one from The Rod Shop. We figured the muscle car muffler would be just right. DOH! STILL too loud. Not really any quieter than the last one. I was kinda pissed since they suggested it.

Note: I've never noticed any difference in how the car runs no matter what exhaust I have had, from bone stock to straight through, and everything in between. The only difference is how bad my ears ring and how many communicator batteries I've burned up.

After all this screwing around, and trying to get some more advice from The Rod Shop, I finally ended up with their "Quiet" straight through muffler. It's funny that it doesn't sound any quieter than the Muscle Car version to me. Still, I blew an 86 at Calabogie last year. It has a nice rumbly sound at idle, but is tuned to quiet down significantly when exhaust velocity rises. You can definitely hear the change.

I still keep a turn down in the trailer just in case. There's nothing worse than dragging somehwere only to find out you're out of range.