[RUQWIKR]

Some of us are looking at going to NCM this year. With NCM's 102.5dB limit - what passes, what doesn't without modifications? SS 1LE and / or ZL1 1LE stock, those with no secondaries, those with headers?

Any guidance and also where are the microphone(s) used, we'd appreciate it. Thanks.

[That1guy_tim]

I passed with catless headers and stock NPP. They won't tell you where the mics are. I'm pretty sure one of them is right after turn 3

[olblue75]

LS with LTH’s, hf cats, full Z28 system (2.75 vs. 2.5), an C7 x-pipe.

[RUQWIKR]

ZL1 buddy is catless with stock exhaust, another LT’s with HF cats, ZL1 1LE stock system except gutted secondaries.

[Mountain]

I can't recall for certain, but as far as I know, none of the Camaros at the SCCA TT Nationals last year had an issue with sound. I'm not sure how much that helps you, but maybe gives you some context.

[RUQWIKR]

Originally Posted by Mountain

I can't recall for certain, but as far as I know, none of the Camaros at the SCCA TT Nationals last year had an issue with sound. I'm not sure how much that helps you, but maybe gives you some context.

Thanks - my car and my friends that are looking at going this summer up there range from loud to real loud!

[TheRealJA105]

Originally Posted by Mountain

I can't recall for certain, but as far as I know, none of the Camaros at the SCCA TT Nationals last year had an issue with sound. I'm not sure how much that helps you, but maybe gives you some context.

I did.

I blew 105db in my Callaway SC630 with gutted primaries, stock secondaries, crush pipe/AFM valve delete and stock NPP. I had to close the valves about half way and hold them in place with self tapping screws. I planned for this beforehand and had the valve actuators removed and drilled holes in the rotating part that lined up with slots on the brackets so I could add the self tappers at the track. I'd do this ahead of time or be prepared to lug it out of 3 and stay all the way to the right to avoid the booth on the outside.

1 Lap 1LE did as well with long tubes into NPP. I think he dropped his muffler and added NCMs baffles they sell you into the muffler inlet pipes.

Edit: the white heads/cam SS blew sound too. I showed him what i did and he pretty much did the same thing, but because he didn't drill the holes before he went he just ran the self tapper through the side of the pipe right next to the valve flapper itself to hold it in place.

[davidwarren]

pretty sure the limit is 103, not 102.5. It's hard to say exactly what will work because the atmosphere has a huge impact. Humidity, temp, cloud ceiling, etc... My dad was over 102.5 in the early morning this year in a stock c7 ZR1.
If you are anywhere close, it really comes down to the atmosphere.

[RUQWIKR]

Originally Posted by davidwarren

pretty sure the limit is 103, not 102.5. It's hard to say exactly what will work because the atmosphere has a huge impact. Humidity, temp, cloud ceiling, etc... My dad was over 102.5 in the early morning this year in a stock c7 ZR1.
If you are anywhere close, it really comes down to the atmosphere.

I see Atlanta Motorsports Park (AMP) is at 98dB with multiple micrphones on both sides of the track. Glad COTA, ECR, MSR-Cresson where I usually run have no restrictions.