SVA Noise Test.

[smele]

Hi Chaps,

How tricky does the noise testing get on the SVA? I have a Ford Mustang that seems to be about 101-102dB at the test level of 4000RPM, which is close I know, but on the way up to 4000RPM from tickover it does peak at 115dB. Do they just test at 4000RPM or do they test all the way up from tickover as well. Seems very close to me, but I would rather not have to change the exhausts.

Cheers,
Smele.

[steve_d]

How were you measuring?
The sensor has to be in a specific position. Something like 0,5m back and 0,5m to the side of the exhaust.

Steve

[smele]

As directed from the SVA guide lines, 500mm, exhuast height at 45degrees with a calibrated meter.

[happy jim]

I was 3dB over on my first SVA test, a couple of "tubes" of rolled chicken wire stuffed up the pipes was enought to bring me under the limit. Unfortunatly they blew out soon after the pass ;-)

Jim

[smele]

happy jim said:

I was 3dB over on my first SVA test, a couple of "tubes" of rolled chicken wire stuffed up the pipes was enought to bring me under the limit. Unfortunatly they blew out soon after the pass ;-)

Jim

Ahh, that sounds like a fine idea. Might give that a go. Think I only need to cut 1-2dB.

[splatspeed]

3 db can be cut using a crossover pipe on a V8 as a rule of thump

[Moose.]

If you tell them your engine's max rpm is 5000, then they'll test you at 3/4 of that, i.e. 3750rpm

[smele]

Moose. said:

If you tell them your engine's max rpm is 5000, then they'll test you at 3/4 of that, i.e. 3750rpm

I did consider that, but after some testing, it is quiter at 4000RPM than anything lower. So I am going with the 2/3's of the red line.