Byron in MS

Hey guys....I installed a FabSpeed 1st generation sport exhaust that I got from someone on the board on my 996tt . It is basically two cherry bomb type mufflers stacked. It is LOUD which is fine as I rarely drive the car on the road but mainly do DE's. I ran at Road Atlanta a couple of weeks ago an it sounded awesome. Here's the rub. There is an upcoming event at Atlanta Motorsports Park but they have 98db noise limit. AMP says they have a silencer solution that fits most cars. I assume this is something that inserts into the end of the exhaust pipe? Does anyone have any suggestions on something they have tried? Is there a way to pack the mufflers to quiet them a little?

Kevinmacd

Well inserting anything into the flow of the exhaust is going to cause back pressure, and probably will degrade the operational effeciency of the turbos. I have no answers to a temp solution other than what you posted. Not knowing what the event consists of maybe the inserts are okay!

911racer

Us racer kind of guys, when faced with a temp situation, will make diverters. Basically pieces that fit on the tail pipe and point the (sound mostly) exhaust away from the sound measuring device. I am talking about something that looks like a shoehorn, not a 90 degree pipe piece. Pointing it at the ground does not help, the sound reflects right back up.

Do they really measure the sound during a DE there? I have been to plenty of tracks that say they have a noise limit, but I have not seen them measuring durring a DE.

Do you know that you are over the 98DB limit ? That is pretty loud. Usually turbo cars get away with just zork tubes for racing because the turbos silence the sound well enough.

32krazy!

i used to think 98 db was loud until i registered 110 db in 6th gear at 2900 rpm in the cabin!! 81 mph would make your head hurt! gmg w/c sport exhaust with gmg headers

fly2low

I have used these in the past with success
http://supertrapp.com/product_sections/cat.asp?CatID=27
I have seen people use them in addition to elbows
I have no experience with Atlanta area tracks, but I have seen people barred from running at driving events at LaGuna Secca for sound

Byron in MS

AMP is a brand new track. It just opened 3 or 4 months ago. They had to jump through many hoops to get past local zoning ordinances, so they are monitoring the noise very closely. They are also on the look out for turn downs and other workarounds. I will take a look at the supertrapps! Thanks!

Byron in MS

Ended up going with the 2 Disk Insert from Car Chemistry. They were an easy install and sound great. Not so tinny and raspy as before...much more mellow sound with very little restriction. And several db's quieter!

http://www.carchemistry.com/shop/ind...ct_detail&p=12

Brenton

I just had my fabspeed taken off and sold it in the last couple of weeks, now I find out about this

Kevin

This solution as Kevinmacd mentioned will increase turbine and exhaust valve back pressure. This device is a mechanical potato.. Better suited for a NA engine than a turbocharged engine. We already have a backpressure device in place. Two infact that spin at 180K rpm's..

If it's to loud for a track day, install your stock exhaust.

Byron in MS

Thought I would give everyone an update on my loud exhaust issues. Prior to the DE, they tested my car at 90dB @ 5000 rpm. I never got over the 98dB limit at WOT, so it was a good weekend. As for the Car Chemistry insert being a potato....they didn't seem to rob my car of hp. My seat of the pants dyno said the hp was as good as ever. In fact, I trimmed 5 seconds a lap from my previous visit to AMP when I still had the stock exhaust.