11 replies to this topic

[RallyRed]

Got pinged the other day by the Noise meter at a track day.
96 limit, I went 97.1.
I understand it's a logarithmic scale, so 1.7 over,is more than it seems.
2 x shotgun style pipes out the side.
Never been pinged before, so assume cold/ dense air is the issue?
I dont want to change the exhaust/ muffler , for the rare issue day.

Looking to just fit 2 x 90 degree removable 90 degree down elbows, to only fit if/ when reqd.

Question - anyone had real world experience with the attenuation that pointing pipes at the ground will achieve?
Thanks

[rodomo]

Hoon

[RallyRed]

Hoon

Thank you, I try.

[Shiney005]

No real world experience, but it would have to work, especially with the higher pitched noises. It is the reason that tweeters have to be pointed at your head, while a subwoofer can hide behind the lounge. Did the officials pull you off the track for the day?

[RallyRed]

 rps20210522_155947.jpg   492.14K   8 downloads

 

Black flagged by 2 Laurie.. the 3rd one would have seen us on the trailer.

Some chicken wire, chopped up drink cans, coupla hose clamps and all good as a temporary fix ( very temporary)

I have since also spoken to my exhaust guy who has done plenty of circuit cars, reckons the 90 degree down is a winner.  See how we go. 

Thanks

 

[arrimar]

Are the noise meters on the inside or outside of the track? Fit a lefthand set of pipes or a righthand set depending which track.

[RallyRed]

Yeah, not a bad idea. The 2 tracks we run at typically, are CW & CCW, so would require swaps each time. Will put it as option 2.
Ta.

[UCSLE]

put a plate in the exhaust flange with a smaller diameter hole or lots of holes drilled , works for going over the pits 

[Ice]

You need some old school 18 inch hot dogs 

[ozyozyozy]

Have done that before and had friends done same thing.
We fitted a turn downs on our exhausts to help with that. Cars were still noisey but didnt ping the meter.
How much less db it affects it i cant answer.

[RallyRed]

Thanks gents.

[Zook]

Is that slow old prick in the black and white HSV VL (I think it is) still getting around. Was it Vodaphone?