Search doesn't seem to be working. Wondering if anyone has run their GT2 at LS under the db restrictions. Will it pass stock? If not are there are tricks similar to what you can do with GT3s that would help?

Thanks!

 

ILLCOMM I have run a number of days at LS in my 2008 GT2. First thing to check is whether it is a 92db or 90db day. This year Skip Barber gave a number of days back to the track to rent out and most of them are 90db days. I don't think there is any way that you can pass a 90db day so be careful what you register for. Without being careful I will hit 94 to 95db (measured about 50 feet off the right side of the track mid-way between turn five and turn six). On some days I can short shift to fourth coming out of turn five and hold the rpm below 5000 and make sound. On other days this won't work--all depends on the atmospheric conditions. So, I have Laguna pipes. Remove the existing exhaust tips and install the pipes (about 18 inches long and curved to the left when looking at the car from the rear--the curve is less than 90 degrees and I point the upward by about 45 degrees). Even then I don't go full throttle in third. There is so much intake noise not damped by the Laguna pipes that full throttle is still a problem. Still shift in fourth but not a real problem because we have so much torque. Some people say they sometimes use a roving meter that will catch people with Laguna pipes but in about 25 trips there I have never seen that happen. Good luck it is a great place to drive

 

Are you running stock exhaust system? If yes, the EC standards are pretty stringent and way lower than most/any test tracks. My '08 GT2 (with stock exhaust) at WOT throttle at DE is way quieter than most of the cars (modified) around me...

If you are not running stock exhaust system....then who knows...but Turbos do a pretty good job muffling most of the sound (life ) out of the exhaust...

 

...I have to dig deep now and I have not had to worry about this stuff in about 10 years...

...but I believe that the ECE-R51 (?) noise standard are used to certify all pass cars. Porsches are tested to that standard and the limits on stock exhaust at WOT are way below 90dB. There are different classifications such as Gas vs. Diesel, MT vs. AT, Power/weight, etc. and the test was a 36mph roll on at WOT in 2nd/3rd/etc. gear. But most cars pass at WOT below 82'sh dB.

The measurement can vary a lot (+/-3 db) based on environment, equipment, etc.

So if you have stock exhaust then you should be more than OK...but maybe you don't?

 

My exhaust is stock. I will check to see if its a 90 or 92 day. I am going as part of the BMWCCA Oktoberfest.

 

You will be fine then...

Post some pics...I would love to run at LS some day....

 

It's a 92dB event.....

 

I wouldn't be so confident. I have seen a lot of Porsche GT cars get black flagged for sound and know some people who don't go to LS anymore because of sound issues. You might want to get some pipes made before you go so you don't ruin the trip. The track is very unforgiving because it is run by the county and a lot of politics is involved.

 

Who made yours?

 

I just went to a local muffler shop. They used standard two and a half inch stock and then had to expand it a bit to fit over the 65mm exhaust pipes. Make sure they do some slotting of the end that fits over the pipe so the clamps can bend it easier. Also regularly check the tightness of the clamps as titanium and iron expand at different rates. You wouldn't believe the amount of junk that gets on the track because of badly fitting Laguna pipes that come loose. I forgot to add that my exhaust is stock. Part of the problem is that the right hand side exhaust tip is slanted towards the right and points at the sound station once you are up the track a bit. At that point you are heading uphill and putting a good load on the engine.

 

I agree with this strategy...I guess I am not familiar with this track - I just know that the stock ECE/TUV cert exhaust is not supposed to be this loud! wow! better safe than sorry...

ILCOMM, this sounds like an easy job...but if you run into trouble I will have my guys make up a pair of pipes for you. I am assuming that I can model using my own car. And just run both pipes straight out and then point them in the air like a tobacco pipe?

 

i'll listen to rod, he's a track rat locally and has been doing laguna seca for a long time in his gt2