John Montgomery

As is already well documented here, Lime Rock Park race track is strictly enforcing an 88Db limit at the track so I had to sit out most of the two day session last year. I have a Fabspeed header/muffler package on my GT4 - can anyone recommend a solution (like a temporary auxiliary silencer) that can help lower noise levels. Not interested in Brillo pads or Supertrap thanks (and I have tried turndowns). Any experience with Akropovic noise reduction insert or FloPro Twister?. Thank you.

Blue Chip

Maybe not the direction you want to go - but different Fabspeed muffler would do it. I run FS headers, catless cross pipe, and Maxflo without issue - if I were to keep the same system and move to Supercups it would be past the limit.

Gofishracing

It depends on the car. Speak to Spensor at Speed Sport or Dan at Hairy Dog Garage my first thought. They will help you

Streak

Remove the engine

flatsics

Mark@AMT Motorsport

Can you just swap the stock mufflers back on for Limerock? My Vette has straight pipes, and I just get it on the lift and put the mufflers back on for Limerock and Palmer.

Banango

997_rich

I run a 2010 gt3 with stock side exhaust but GMG center exhaust. It's loud but I've run Lime Rock with no issue. Do you still retain the stock exhaust switch and switchable baffles on your gt4 (sport mode button controls this)? You can pull the vac hoses to those exhaust baffle door actuators and cap the line. That will force the baffles to stay closed (quieter).

John Montgomery

Thanks - I had to dump the switchable baffles because if you keep them closed at high revs, the valves burn out. I also now have bigger diameter over-pipes which would not fit into the stock muffler.

John Montgomery

You're right - but its worth a try, it would be a shame to leave LRP off the schedule..

John Montgomery

I have larger diameter headers and over pipes which unfortunately don't fit into the stock muffler - and unfortunately even stock GT4's got black flagged as soon as their baffles opened at high revs..

John Montgomery

Now that looks like it will quieten things down a bit - and brew a little moonshine between track sessions..

Mark@AMT Motorsport

Don't forget that are several unmuffled days at LRP per season. NASA, SCDA, and HOD all have at least 2 days there this year I believe unmuffled. I usually just try and go to toss events rather than sweating the sound level.

PorscheAddict

I don't know how you deal with 88db. I think a bone stock Cayman is around that at WOT.

38D