Exhaust too loud for tracks?

[shiraz]

Hey follow GT350 crew!

I was at a track day at Sonoma Raceway last week (left my GT350 at home, took my Subaru STI instead) and there was a guy with a brand new GT350R straight from the dealer. Sonoma's dB limit is 89, and the R at full throttle out the last turn where the mic is was doing 115+dB on the straight!!! So the guy with the R obviously got kicked off the track.

Laguna Seca is even more strict with sound limit, and those are my local tracks. :doh:

I was considering a Borla exhaust for my GT350, but after seeing how easy it is to get kicked off a track day that you've paid a good chunk of change for, I've changed my mind. I'm HOPING the GT350 stock exhaust is quiet enough even at full throttle, otherwise I'll need to sand bag the main straights every time and not go past half throttle while keeping the sound baffled. Which of course isn't as much fun!

Has anyone with a non-R with factory exhuast been black flagged for sound? I'm not sure if you guys at other tracks have to deal with this, but things are stricter in my area apparently.

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[TonyJ5150]

Problem is with the stock exhaust under WOT, the valve opens and lets all hell out those pipes. There is no way to keep the valve closed under WOT that I'm aware of...as a result, if I cant find a work around, I may need to go with a normal muffler that does not use the valve system that will give good performance and be under the noise limits...

 

[shiraz]

Yeah, exactly, so my plan is if folks have indeed had this issue, to just half throttle near the mic and just continue to have fun on the turns instead of straight.

 

[wildcatgoal]

Short shift. You aren't racing anyway.

 

[SchultzLT1]

Is unplugging the valves an option?

 

[mattlqx]

I've never seen a Sonoma day with a limit so low as being 89db. Laguna days are typically 90 or 92, but I have seen some 88 days. I was just up at Sonoma at the end of August with my 350 (see video here http://www.mustang6g.com/forums/showpost.php?p=1471709&postcount=151) with resonators removed with no problem, I ran in exhaust open the whole time. The limit was 104db I believe. The other 350s there with me (including an R) didn't get flagged either. The louder Bosses (with basically no mufflers) did get flagged though and caused them to have to short shift a lot.

I do wonder if that was a mobile measurement that they claimed 115db on. Placement Is everything, but that's extremely loud.

 

[nastang87xx]

Is unplugging the valves an option?

No, the drive modes will freak out and you'll throw a CEL.

 

[5.0 435]

There was a R @ a small car show on Saturday . I swear you could hear him shifting a mile away. Never heard a R on the street before ....but they are certainly loud. Loud in a good way.

 

[shiraz]

I've never seen a Sonoma day with a limit so low as being 89db. Laguna days are typically 90 or 92, but I have seen some 88 days. I was just up at Sonoma at the end of August with my 350 (see video here http://www.mustang6g.com/forums/showpost.php?p=1471709&postcount=151) with resonators removed with no problem, I ran in exhaust open the whole time. The limit was 104db I believe. The other 350s there with me (including an R) didn't get flagged either. The louder Bosses (with basically no mufflers) did get flagged though and caused them to have to short shift a lot.

I do wonder if that was a mobile measurement that they claimed 115db on. Placement Is everything, but that's extremely loud.

Yeah they were super strict last Wednesday... maybe it was a special day, or a weekday thing? But they were flagging everything over the limit. 2 Corvettes and 3 911's got kicked, but all had aftermarket exhausts.

What group were you with when you went for your Track Day?

Some instructors at the track were saying maybe sounds was bouncing off the walls since the car was alone when it was near the mic, but that's the reading they said it gave off.

 

[doz]

I've never been to a track day at Sonoma that had a limit under 100db. At laguna you will have to lift going up the hill after turn 5 to pass sound unless someone makes laguna pipes like many have made for porsches. ( http://www.sharkwerks.com/products.php?pid=281 )

You could always go up to thunderhill where you'll never have to worry about sound or disturbing anything other than cows.

 

[krt22]

Yeah sonoma is normally 104dB. Definitely something funky with a 115 dB reading, I think the R or a GT350 without resonators is closer to the 104dB area (C&D have it at 104dB from 50ft away). Usually they will give you one warning and the next time you violate it they boot you, so weird day indeed

 

[mattlqx]

Yeah they were super strict last Wednesday... maybe it was a special day, or a weekday thing? But they were flagging everything over the limit. 2 Corvettes and 3 911's got kicked, but all had aftermarket exhausts.

What group were you with when you went for your Track Day?

Some instructors at the track were saying maybe sounds was bouncing off the walls since the car was alone when it was near the mic, but that's the reading they said it gave off.

It was an HOD day on a Thursday. Environmental conditions and distance changes the reading so it's hard to speculate. I still think a limit that low is uncommon for Sonoma though, but it's been about a year since I've been there with some frequency.

See also: https://www.facebook.com/mattlqx/videos/10210640148668102/ The red and black Bosses were the ones that kept having sound issues, even at Thunderhill the following days, which is in the middle of nowhere and for some baffling reason still has a sound limit.

 

[shiraz]

Yeah sonoma is normally 104dB. Definitely something funky with a 115 dB reading, I think the R or a GT350 without resonators is closer to the 104dB area (C&D have it at 104dB from 50ft away). Usually they will give you one warning and the next time you violate it they boot you, so weird day indeed

They did get a warning which I forgot to mention. So he said he kept the exhaust in normal mode after the warning, but obviously that doesn't do anything at WOT so that's when he got kicked after.

 

[FPCV8YO]

I've never seen a Sonoma day with a limit so low as being 89db. Laguna days are typically 90 or 92, but I have seen some 88 days. I was just up at Sonoma at the end of August with my 350 (see video here http://www.mustang6g.com/forums/showpost.php?p=1471709&postcount=151) with resonators removed with no problem, I ran in exhaust open the whole time. The limit was 104db I believe. The other 350s there with me (including an R) didn't get flagged either. The louder Bosses (with basically no mufflers) did get flagged though and caused them to have to short shift a lot.

I do wonder if that was a mobile measurement that they claimed 115db on. Placement Is everything, but that's extremely loud.

Yea, I believe it was Car & Driver just recently who claimed 104db on an R.

 

[Superdog]

Off topic:

He took his R straight from the dealer?

I'm under the impression that this is a very bad thing. Don't you need about 1,000 miles and an oil change first?

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