Board logo

Noise Level
Johnmor - 8/5/06 at 08:16 PM

Can anyone help.
Is the noise level during the SVA tested under load or just free reving.
I have a noise meter and I can get around 100db free but under load the v6 gets a bit noisy, touching 108db.

I am was hoping to sneak through but if its under load i wil have to think again.


David Jenkins - 8/5/06 at 08:19 PM

Free-revving.

In my case I parked the car, the tester stood his meter at the same level as the outlet but 30 degrees to the side (a set distance away - can't remember how far), then I revved up to the specified speed (he looked in to check the tacho!). Ran for about 10 seconds or so, then he told me to stop the engine. Job done.

Remember that if yours is a V then he'll measure on both sides.

David

[Edited on 8/5/06 by David Jenkins]


Hellfire - 8/5/06 at 08:38 PM

The noise level is checked at 75% of the declared Peak Power RPM on the SVA application form. ie, If you declare 10,000 rpm for max power, the noise is tested at 7,500rpm. Thats with free revving and under no load.

HTH
Phil


muzchap - 8/5/06 at 08:50 PM

Hmm thats cunning - so all ya need to do is work out where it rises and ensure that's less than 75% of indicated revs.

Useful to know


Hellfire - 8/5/06 at 09:15 PM

Having said that, the SVA Inspectors aren't daft. They've seen enough kit cars go through to know what's a realistic RPM figure and what's not, for most types of engine. If they suspect it's grossly incorrect, they will ask for the manufacturers details as proof. You might get away with upto 1,000 rpm on a car engine and maybe 2,000 on a bike engine but not much more.

Could be the difference between a pass and a fail though. So in the immortal words of Mr Eastwood - “Do you feel lucky punk? Well, do ya?”

Phil


westf27 - 8/5/06 at 09:49 PM

a db killer worked for me,lost five db on retest.


Johnmor - 9/5/06 at 06:10 AM

whats the best place to get a Db killer?


westf27 - 10/5/06 at 10:23 PM

http://cgi.ebay.co.uk/Baffle-for-race-exhaust-can-decibel-killer-DB-killer_W0QQitemZ8062223308QQcategoryZ25623QQssPageNameZWDVWQQrdZ1QQcmdZViewItem