Help? Exhaust noise restrictions (on my FC at Lime Rock)
#1
Help? Exhaust noise restrictions (on my FC at Lime Rock)
Not sure where to post this, I figured the "track people" would know more about this than anyone.
Next month I am looking to do an HPDE event in my turbo FC at Lime Rock park. This track has a strict 86db limit.
My car has a BNR stage 1 turbo upgrade, a racing beat 2.5inch downpipe and presilencer. The rest of my exhaust has generic stock sized pipes and mufflers. It's definitely quieter than other rotary cars, but still loud for a road car.
Does anyone have any idea how loud this car is going to be? Anyone know how/where do I test before hand? I'd hate to show up and not run (and not get a refund!) due to being too loud
I've seen other cars at previous HPDE events (on this course) that are obvious track cars; souped up and somewhat noisy, and they were able to run.
However, I've also seen some cars with the "beehives" sticking out the exhaust, or steel wool jammed in the pipes.
I haven't seen too many rotaries at this track: Only a 2nd gen NA track car (it had the beehives), and a 3rd gen. But this was two years ago and I can't recall the noise levels then.
If anyone has any advice and/or can help, I'd appreciate it.
Thanks
Next month I am looking to do an HPDE event in my turbo FC at Lime Rock park. This track has a strict 86db limit.
My car has a BNR stage 1 turbo upgrade, a racing beat 2.5inch downpipe and presilencer. The rest of my exhaust has generic stock sized pipes and mufflers. It's definitely quieter than other rotary cars, but still loud for a road car.
Does anyone have any idea how loud this car is going to be? Anyone know how/where do I test before hand? I'd hate to show up and not run (and not get a refund!) due to being too loud
I've seen other cars at previous HPDE events (on this course) that are obvious track cars; souped up and somewhat noisy, and they were able to run.
However, I've also seen some cars with the "beehives" sticking out the exhaust, or steel wool jammed in the pipes.
I haven't seen too many rotaries at this track: Only a 2nd gen NA track car (it had the beehives), and a 3rd gen. But this was two years ago and I can't recall the noise levels then.
If anyone has any advice and/or can help, I'd appreciate it.
Thanks
#4
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86db? thats quieter than laguna, and stock cars have trouble.... i've done some reading on noise/sound and its a really weird subject!
1. find out where the sound meter is.
1a. the last track event i did, i was flagged for sound, but if i lifted right before the sound booth, that fixed it.
2. to get it really quiet the intake matters also. stock airbox is quieter than a cone...
3. with the exhaust it does help to point it away from the sound meter, hence the weird pipe extensions and things you'll see. some people even run an extra muffler.
4. hope the weather is good! we got flagged for sound, over 103DB, and Jack went back the next weekend and it was under 103, the difference? a cloud! seriously.
1. find out where the sound meter is.
1a. the last track event i did, i was flagged for sound, but if i lifted right before the sound booth, that fixed it.
2. to get it really quiet the intake matters also. stock airbox is quieter than a cone...
3. with the exhaust it does help to point it away from the sound meter, hence the weird pipe extensions and things you'll see. some people even run an extra muffler.
4. hope the weather is good! we got flagged for sound, over 103DB, and Jack went back the next weekend and it was under 103, the difference? a cloud! seriously.
#5
^i've read that weather has does effect it. End of October though I imagine cool, dense air. Maybe that will quiet things?
I was thinking of getting some cheap 90 degree elbows and putting them facing downward on the back of my car, that could help a little.
I was thinking of getting some cheap 90 degree elbows and putting them facing downward on the back of my car, that could help a little.
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elbows are nice to have, get some good clamps too.
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#10
86 dB is very low, I would try a 90 elbow pointed in the other direction from the meter.
#11
86 is very low. Some performance vehicles STOCK will get flagged. When I was there in June one guy in my group was flagged and he had a stock Elise!
I wonder if the town ever complained about all those harleys...
In the mean time I've ordered a decibel meter from ebay. The **** I buy for this car...
thanks everyone!
I wonder if the town ever complained about all those harleys...
In the mean time I've ordered a decibel meter from ebay. The **** I buy for this car...
thanks everyone!
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