Measure exhaust noise

[tricker_luke]

Where can I go to have my DC5 noise level measured? I've got a Spoon N1 backbox which states 110db so is this an obvious fail for most track days (100db), or is it not measured like that?


Edit** It's ok now, I have found a mini sound level meter from Maplin for £15 so I'll be buying that tomorrow.

 

[Judley]

Where can I go to have my DC5 noise level measured? I've got a Spoon N1 backbox which states 110db so is this an obvious fail for most track days (100db), or is it not measured like that?


Edit** It's ok now, I have found a mini sound level meter from Maplin for £15 so I'll be buying that tomorrow.

I think there is more to it than just the rating on the backbox mate as noise is going to come from lots of different areas. Most tracks stipulate that the db limit is taken at 3/4 maximum revs so you would need to take the measurement at 6,300rpm and the meter needs to be one metre from the exhaust. I'm not sure how accurate the Maplin meter will be but the safest thing is to take it to the track nearest to you and ask them to check it for you. You will get a reliable reading as their units will be regularly calibrated.

Cheers,

George

 

[tricker_luke]

How would they take it at 6,300rpm though when stationary?

 

[Judley]

How would they take it at 6,300rpm though when stationary?

Select neutral and hit the loud pedal mate :green:

 

[shauny]

Do they not hit the limiter at 5000rpm

 

[Judley]

Do they not hit the limiter at 5000rpm

Didn't know that shauny, apologies (new to the DC5). In that case, probably claim to the scrutineer that the rev limit is 6,800rpm \/ That will also keep it out of the Vtec zone O

 

[Rob.]

When my engine was standard with Spoon manifold, down pipe and system with engine at 5500rpm static test it was 98 to 99db so you shouldnt have too many problems..

 

[lockwood77]

Depends on the track, some are drive-by, you can't replicate that stationary because VTEC won't engage - the car is a lot noisier under load!

Donington is (was) the worst at 98db drive-by, my Toda/GruppeM just sneaks under that, can't imagine a Spoon will get anywhere near it. Silverstone is drive-by too, Cadwell is static. Can't remember Rockingham and Oulton, don't recall having a noise test so probably drive-by.

 

[Rob.]

Oulton is static and Rockingham drive by tests.

Oulton still test on drive by as well as static though as I got black flagged there last year..

 

[tricker_luke]

What happens though if you get to the track and the car is too loud for it, after paying etc because you didn't know how loud it was before hand?

 

[Judley]

What happens though if you get to the track and the car is too loud for it, after paying etc because you didn't know how loud it was before hand?

Unfortunately you go away with your tail between your legs mate I got thrown off at Castle Combe in my Skyline in the afternoon when I think the baffles went in my exhaust and I saw a TVR get thrown out before he had turned a wheel. Definitely get it tested before you go as these guys are red hot on noise now.