Local track sound limit

[dharts9]

I’m currently gearing up my 10r80 for some local HPDE and realized one of my local tracks (summit point motor sports park) has a decibel limit of 103. I have a MBRP race catback and it’s on the loud (not loudest) end of the spectrum. Before I go and get a decibel reader wanted to see if this is a common rule for tracks or is anyone has the same exhaust and knows the approx. decibels?

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[johnson.ba]

Download a free decibel meter app on your phone. Go to the tracks website and they should tell you how to test your exhaust at home to make sure its compliant.

One of the three real racetracks in AZ has a sound limit and its like 96dB. I'm on stock exhaust so I don't have to worry.

 

[ddozier]

I’m currently gearing up my 10r80 for some local HPDE and realized one of my local tracks (summit point motor sports park) has a decibel limit of 103. I have a MBRP race catback and it’s on the loud (not loudest) end of the spectrum. Before I go and get a decibel reader wanted to see if this is a common rule for tracks or is anyone has the same exhaust and knows the approx. decibels?

103db is a fairly liberal level and unless the car is without cats and has long tubes you will likely pass. Using a phone app will give you a good idea of what to expect and knowing the process they will use to measure is going to be helpful. If they say they are measuring at 50ft, I would make all my measurements at 40ft to give myself some wiggle room. Also temperature, humidity and all kinds of environmental conditions factor into the reading so it may be a good idea to do more than one test if your first test results come back close to the limit. Also sound is an accumulative thing, so while your car alone my be within limits you running close to another loud car may put you over the edge so its best to have a 2-3db safety margin. Some tracks will give you a warning if you exceed the limit and give you a chance to solve the problem others will tell you that you are done for the day until you make a significant change. The local communities are driving this issue and some have imposed fines and other punitive actions on the tracks for exceeding the noise limits.

My car is flat out loud, it is headers, no cats, simple single 2 in 2 out muffler and dumps just past the axle. My car measured 98db at NCM on a 75* day. I had to rework my exhaust several times to get it below 100db as that was my target. I had to add the 2 additional resonators to get it under 100db as I would consistently hit 101db without them. Dumping the exhaust under the car instead of out the back made the largest difference when measuring from further away from the car. Hope you do not have to change anything but if you do this works and was simple to build. As easy as it is to change the exhaust you may want to consider a loud and louder setup and change it when needed.

Here is an my exhaust layout
:

Dave

 

[dharts9]

103db is a fairly liberal level and unless the car is without cats and has long tubes you will likely pass. Using a phone app will give you a good idea of what to expect and knowing the process they will use to measure is going to be helpful. If they say they are measuring at 50ft, I would make all my measurements at 40ft to give myself some wiggle room. Also temperature, humidity and all kinds of environmental conditions factor into the reading so it may be a good idea to do more than one test if your first test results come back close to the limit. Also sound is an accumulative thing, so while your car alone my be within limits you running close to another loud car may put you over the edge so its best to have a 2-3db safety margin. Some tracks will give you a warning if you exceed the limit and give you a chance to solve the problem others will tell you that you are done for the day until you make a significant change. The local communities are driving this issue and some have imposed fines and other punitive actions on the tracks for exceeding the noise limits.

My car is flat out loud, it is headers, no cats, simple single 2 in 2 out muffler and dumps just past the axle. My car measured 98db at NCM on a 75* day. I had to rework my exhaust several times to get it below 100db as that was my target. I had to add the 2 additional resonators to get it under 100db as I would consistently hit 101db without them. Dumping the exhaust under the car instead of out the back made the largest difference when measuring from further away from the car. Hope you do not have to change anything but if you do this works and was simple to build. As easy as it is to change the exhaust you may want to consider a loud and louder setup and change it when needed.

Here is an my exhaust layout
:

Dave

Thats good to know...I have cats but technically no muffler but MBRP has a small tubular area near the exhaust tip that helps produce their specific sound (idk why they dont consider it a muffler). I definitely am glad I actually read the rules and stuff b/c I def would hate to have to leave and fix it esp after having paid.

Thanks again, I'm going to check out one of those apps.

 

[umarov]

I’m currently gearing up my 10r80 for some local HPDE and realized one of my local tracks (summit point motor sports park) has a decibel limit of 103. I have a MBRP race catback and it’s on the loud (not loudest) end of the spectrum. Before I go and get a decibel reader wanted to see if this is a common rule for tracks or is anyone has the same exhaust and knows the approx. decibels?

I had no idea Summit Point had decibel limit. I have Solo Mach thunder. I hope I won't have issue in the future. I will also need to measure mine to have a reference point

 

[dharts9]

I had no idea Summit Point had decibel limit. I have Solo Mach thunder. I hope I won't have issue in the future. I will also need to measure mine to have a reference point

I used an app as suggested but I need to obviously have it checked while revving. Have you been to Summit Point before?

 

[umarov]

I used an app as suggested but I need to obviously have it checked while revving. Have you been to Summit Point before?

I have. I went there for TrackCross. There was no mention of a decibel limit. We also were on the Shenandoah track. So maybe the main track has the limit. Only limit we had was the quiet hour from 11 to 12. That's Sundays only I think

 

[mikeD4V]

You should be fine for summit. My CB is similar to yours and have run all three tracks at summit with no gaff about noise. I’ve never been the loudest car, by far, either.

 

[Cardude99]

My buddy is running a Corsa sport on his 18 gt w/ an x pipe. 105 db @ 150 ft. Hopefully this helps someone.

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