ShiftLess

I'm scheduled for a HPDE event at LRP in April and my newly acquired C6 has a really loud exhaust system which I think is a SLP Loudmouth. I think it has the resonators not the mufflers. I've only had a quick look at it and didn't see the SLP logo but it is really loud.

My understanding is LRP tests for ~85db and will not let you run if louder.

Has anyone run LRP with an aftermarket exhaust during a non racing event? Is there anything I can do to the system to muffle it? ie stuff fibreglass in to the tail pipe?

I'm checking Craigslist for a stock system but also want to know if I add headers in the future if that will also put it over the limit??? I mean if I got to a stock muffler with headers...

BierGut

Chances are you will be too loud. We have no idea just how loud your car is, but it doesn’t take much to break the 85db barrier. If you are close to that level a bright clear day will offer a “slight” help to an overcast low ceiling, but it’s nothing to count on. Over the years, I’ve known many who try to lift where the gentleman stands with the meter – but he will move around the course.

Best guess for you is you’ll be too loud. Track days are expensive and lodging there is stupid so perhaps consider bailing if you’d rather not change that exhaust.

Also, as a side note -- given it’s an April event the residents will usually be a little more sensitive as the season gets underway after a quiet winter. If I were going to try and push my luck it would be much later in the season.

68sixspeed

you are hosed... put some stock mufflers on for LRP, they are usually easy/cheap to find. I've seen stock M3's get the loud flag depending on the weather. Headers on stock mufflers are right on the borderline.

Tim Ware

Before major surgery, try motorcycle baffles. Many motorcycle exhaust systems can accept an internal baffle of various sizes that are supplied by aftermarket manufacturers. They just slide inside the pipe and are secured with a single bolt.
Try eBay and look for " baffles " in a motorcycle category. They restrict flow a little, but they do reduce sound.

Tim Ware

I just looked at eBay under " Motorcycle Baffles " & found 442 baffles. Perhaps there's one for you ?
Tim

BPHORSEGUY

LRP has days with no restrictions. Even on the restricted days my car and my buddies cars are very loud and no one has ever had a problem?