V6S noise (dB?)

[Chris71]

Hi,

Does anybody know what sort of SPL range a relatively standard non-cat S3 exhaust occupies?

I'm wondering if I can take mine to Rockingham, without a very long miserable drive home after the noise test!

Chris

[Mr Plow]

Had mine tested at Castle Combe last week, S3C with the cats removed. It recorded a reading of 98.5 db.
The limit is 100db at Castle Combe.

[tvrgit]

Yeah, that seems like a typical value - my decatted S3C reached 99-point-something at SCH in 2007, and that was with the exhaust blowing half of the gas out of the downpipe joint.

Jim Tully's was the loudest V6 at SCH07 and SCH08, at 111 dB I think it was.

Edited by tvrgit on Monday 23 March 18:55

[Wiz]

Hope someone brings a db meter to this years S club, mines standard but would like to know what its putting out.

[Roy C]

Chris71 said:

Hi,

Does anybody know what sort of SPL range a relatively standard non-cat S3 exhaust occupies?

I'm wondering if I can take mine to Rockingham, without a very long miserable drive home after the noise test!

Chris

Hi Chris,

As I mentioned at the Ace Cafe, the exhaust noise levels on V6 S-series are quite widely variable. My "standard" mild steel exhaust is around 100db. I believe the track day limit at Rockingham is 105db.

Roy

[pwd95]

Hi Chris, mine was 107db at Castle Coombe last year. Don't know if you can judge yours against mine from memory. .

[Chris71]

pwd95 said:

Hi Chris, mine was 107db at Castle Coombe last year. Don't know if you can judge yours against mine from memory. .

I remember most of the noise from yours coming from the tyres.

[Dave_M]

Hi Wiz, I may be wrong but IIRC our db metre from SCH08 is no longer available to us, so if anyone has one we can use.....

[Chris71]

[plug]
I believe someone's bringing a noise meter to the PH North London meet in Crews Hill near Enfield this Sunday.
[/plug]

[steve j]

tvrgit said:

Yeah, that seems like a typical value - my decatted S3C reached 99-point-something at SCH in 2007, and that was with the exhaust blowing half of the gas out of the downpipe joint.

Jim Tully's was the loudest V6 at SCH07 and SCH08, at 111 dB I think it was.

Edited by tvrgit on Monday 23 March 18:55

Ahem!

[tvrgit]

steve j said:

tvrgit said:

Yeah, that seems like a typical value - my decatted S3C reached 99-point-something at SCH in 2007, and that was with the exhaust blowing half of the gas out of the downpipe joint.

Jim Tully's was the loudest V6 at SCH07 and SCH08, at 111 dB I think it was.

Edited by tvrgit on Monday 23 March 18:55

Ahem!

Oops sorry Steve - you were last year, Jim was the year before.

[Chris71]

Done! It peaked at about 98dB, but depending on what engine speed they wanted and how gently I can raise the revs I reckon it should be under that for the actual test.

[Roy C]

AFAIK the static test is around 3000rpm with the meter at 50cm from the tailpipes.

[Chris71]

Roy C said:

AFAIK the static test is around 3000rpm with the meter at 50cm from the tailpipes.

This was from more like a metre away, but up to 6000rpm, so should be more than okay for 105dB I reckon. Rockingham here I come!

[Roy C]

Chris71 said:

Roy C said:

AFAIK the static test is around 3000rpm with the meter at 50cm from the tailpipes.

This was from more like a metre away, but up to 6000rpm, so should be more than okay for 105dB I reckon. Rockingham here I come!

The more I think about it, I think it's probably 4000rpm (two-thirds max).
I could be wrong. Anyone know?

[zombeh]

They're usually tested 0.5m away at 45 degrees at 3/4 revs. Some places test at a fixed rpm rather than 3/4 max.

I can see almost no mention of noise testing on rockingham's website, only this
[quote]Rockingham's noise limit is 103db. Road cars should fall under this limit, if in doubt a noise test can be
done on the day. Race cars must be silenced to at or lower than 103db. Noise testing will be carried out
on the day and if you fail the noise test you will be asked to rectify the situation before you are allowed
back out on track.
[/quote]

Edited by zombeh on Tuesday 31st March 10:43