Could anyone please tell me what the usual method for sound tests are at track days.ie distance from exhaust and RPM on static test ditto for drive by.I have been told that a lot of tracks are quite tolerant within reason!.What have been other peoples experiences and has anyone been stopped for this reason.I ask because I have hired a meter from book-a-track and am looking to book a few days shortly.Also A good question Isuppose would be where are the more tolerant venues
[color:“white”] [/color] Cheers
Steve [color:“blue”] [/color] [color:“white”] [/color]
You have to check each venue and each date as some have noisey days and quiet days - here is a typical “low noise one” - Look at venue information on the Bookatrack site.
98dB @ 0.5m, 45� from Exhaust, � max RPM. 87� dB Drive-by
Bear in mind that the 3/4 max RPM puts an exige at 6K - you can try it lower to cheat a bit but often you get too much “burble” or missing so try your noise meter at different RPM’s but bear in mind they often have no idea what the max is and will often accept anywhere from 4.8K upwards
Try to hold the revs steady as well at your chosen setting, this can have a great effect…
Driveby is not just exhuast noise, so inlet roar/reasonance can have an effect on that.
Its worth noting that the 0.5m at 45 degree is the same as the MSA 12.17.8 and here they state that measurements must be taken outside with no large reflecting objects ( walls etc ) within 3m and background noise should be at least 10dba below the tested level.
The driveby should be done witin 8m of the car as that is the maximum where the direction is controlable.
My car with 190 upgrade, plus Supersports exhaust & de-cat pipe was regularly measured at Oulton at “bang on” the 106db limit - but at [color:“red”]5250 rpm!!! [/color]
Last week, at Oulton, after fitting the Eliseparts silenced de-cat pipe, I asked (cos they weren’t going to do it) to be sound tested. Result = [color:“green”]100db at 5750 rpm [/color]
Is the Elise parts replacement something that can be done at home or a dealer job?.Anxious to get this sorted as I spent a day at Elvington a couple of weeks ago and it’s sort of give me the erge to do a few more track day’s.(If I can afford the tyres)
Thank’s Rob, Looks like the next job then.I have a set of spanners a trolley jack and stands,just need to get the mrs a pair of overalls and job’s a good un.Oh and by the way I have a funny story about a sun visor when you have five.
Without stating the obvious (oh go on then, I will!) - make sure your car is warmed through prior to a noise check - cold exhausts are much noisier.
My car is about 107 dB when cold (according to MSA scrutineers at Sprints), and drops to 102 dB when above about 65 degrees - and you don’t want to be thrashing it at high revs colder than that anyway
Ok ,so today I did a test with the meter at .5mtr at 45 degrees from the exhaust reading at a constant 5000rpm was 101db,but lift off to quick and the resulting snap crackle and pop wang the metre around to 117db.So i think the answer must be rev the car if tested to about 4500rpm and then gently lift off. should give me a reading of about 98-99 db (according to my mate with the meter).Or am I being a little to optimistic.
