Noise

[Mr E]

The 11 year old bucket of bolts sailed through another MOT today - no worries at all.

Every year, the emissions test usually draws a round of applause (hold the car at revs for a bit, in a metal shed - it's a bit noisy).

I wondered *how* noisy exactly. For a couple of reasons, while there is no set maximum for a road car, as we know most racetracks have a strictly enforced limit. And conversations can end up in dick measuring contests without any actual measurements being taken (so to speak)

So I got hold of the appropriate kit, held it at about a meter away outside with no walls to reflect sound off, not in a direct line or pointing at the exhaust. And Sarah held the car at 4000rpm for 10 seconds or so.

102.8dBA. Eeek.

Coombe is 105dBA at half a meter away and 3/4 of the redline (so 4500rpm). So it's going to be tight - I suspect I'll need the additional silencer.

For reference, the Alfa (which is not a notably quiet car in the grand scheme of things) recorded 91.8dBA at 4000rpm.

[Vixpy1]

Mazda 86db when last tested, TVR 116db, hopeing we can get the scooby in at under 98db.

[Bibbs]

Have a look here :

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

It's where I had a conversation with Vosa about the legal requirements.

I was about 116dB @ 4,000 rpm .. That's off boost and off cam.
So it's new exhaust and bung time.

[Mr E]

Bibbs said:

Have a look here :

http://www.pistonheads.co.uk/gassing/topic.asp?h=0...

It's where I had a conversation with Vosa about the legal requirements.

I was about 116dB @ 4,000 rpm .. That's off boost and off cam.
So it's new exhaust and bung time.

Read with interest and indeed commented on.