PDA

View Full Version : Exhaust sound level for track days?


nzspokes
28th December 2012, 09:48
Is there a way to get the bike tested before a track day? Ive gutted the stock muffler but its not to bad. I just want to check it so we don't have trouble on the day. The bikes a Hyo 650.
steve_t
28th December 2012, 11:08
Maybe try an SPL meter on a smartphone of some kind. Ride by with the phone 30m away and it should read less than 95dB. I think that's the track reg
ktm84mxc
29th December 2012, 08:50
First whats the noise level you need to reach for MX it's 96 decibels at 3/4 throttle .
scott411
4th January 2013, 09:46
First whats the noise level you need to reach for MX it's 96 decibels at 3/4 throttle .

the offical MX test is at much less than 3/4 throttle, and so easy to beat its not funny, (its a piston speed calculation, can't remeber the actual rpm's but its under 1/2 the maximum on the four strokes)

Road racing uses a much better fly by system, where its 95db from a point off the track (30 metres from memory)

so with out a DB metres, a fast straight, and someone watching it, its pretty hard to measure away from the track
tbs
5th January 2013, 21:41
Which track? I asked the MotoTT guys as I was worried about mine and said it was a complete non issue at Taupo. I don't think you'll have to worry anyway.
nzspokes
6th January 2013, 06:11
Which track? I asked the MotoTT guys as I was worried about mine and said it was a complete non issue at Taupo. I don't think you'll have to worry anyway.

ART day at HD, Feb I think if I can find a cow big enough to make some leather pants out of.
malcy25
8th January 2013, 09:53
I would expect you would be safe with stock exhaust, with no issues.


Most circuits will have some form of limit which is <96db at 30m which is aligns with the MNZ rule book (or vice versa). There was a very long discussion in the racing section a while back on this.
nzspokes
8th January 2013, 10:08
I would expect you would be safe with stock exhaust, with no issues.


Most circuits will have some form of limit which is <96db at 30m which is aligns with the MNZ rule book (or vice versa). There was a very long discussion in the racing section a while back on this.

Ive gutted the stock muffler. Still has some baffels though.