Quite enough for a 98db trackday?
Discussion
Booked on to Goodwood thinking Id be OK but having doubts already.
The limit is;
98db
45degree angle
0.5 meters away
whilst at 3/4 max revs.
I think I alreday tested mine and got 96Db but now I cant be entirely sure.
Is 3/4 revs going to be 4500? Are they going to try and push me higher than that?
My Griff is a standard 500 '96 (Serp).
Just been serviced and one new manifold and pre-cat so is sounding nice and smooth.
The limit is;
98db
45degree angle
0.5 meters away
whilst at 3/4 max revs.
I think I alreday tested mine and got 96Db but now I cant be entirely sure.
Is 3/4 revs going to be 4500? Are they going to try and push me higher than that?
My Griff is a standard 500 '96 (Serp).
Just been serviced and one new manifold and pre-cat so is sounding nice and smooth.
The noise test guys at Goodwood are friendly if you don't antagonise them; they will do everything they can to get you out on track if you don't wind them up by questioning their parentage or the accuracy of their noise meter. 
You specify what your max revs are, and hence what the 3/4 revs used for measurement will be. If you're only going to use 5,500rpm on track then tell them that.....
Goodwood also has drive-by noise metering that could cause you to be black-flagged if you trip them: again if necessary some good advice will be given as to where you need to lift to continue....
You specify what your max revs are, and hence what the 3/4 revs used for measurement will be. If you're only going to use 5,500rpm on track then tell them that.....
Goodwood also has drive-by noise metering that could cause you to be black-flagged if you trip them: again if necessary some good advice will be given as to where you need to lift to continue....
Thanks again JC!
Just been reading up on the drive by sound test. I guess I'll have to find out where they are going to be!
My max revs will actually be 5500 so that at least knocks the 3/4 noise level down a bit.
Fingers crossed all will be well. They sound like a good bunch anyway which as stopped me worrying so much.
Just been reading up on the drive by sound test. I guess I'll have to find out where they are going to be!
My max revs will actually be 5500 so that at least knocks the 3/4 noise level down a bit.
Fingers crossed all will be well. They sound like a good bunch anyway which as stopped me worrying so much.
If worst comes to the worst, can you get silencer inserts for the tailpipes? I know you can for some cars, not sure about TVR. Clearly it'll reduce power but I'd rather have a slightly throttled car going round the track than a noisy car sat at the side of the track watching all my friends going round 
On the DB reading thing, I went on a trackday last year in the FTO. They were testing noisier FTO's at 3/4 throttle, but letting the owner actually rev it. This meant that one particular guy could hold it at 5000rpm, a couple of hundred before the high-lift cams kick in and double the noise level
On the DB reading thing, I went on a trackday last year in the FTO. They were testing noisier FTO's at 3/4 throttle, but letting the owner actually rev it. This meant that one particular guy could hold it at 5000rpm, a couple of hundred before the high-lift cams kick in and double the noise level
wildeep said:
When I was at Goodwood they tested mine at 4k revs and it was 97DB from one pipe and 102DB from another, so he called it 98DB. Not sure why they were different?.
Is yours standard?
I think I know why they were different.
from the engien it goes 8-2-1 into the silencer. it then comes out of the silencer as 2 pipes.
One of these two pipes is in line with the one going in and hence its louder.
Thats pure guess but I reckon thats the reason why.
I bet it was the left hand one that was loudest (assuming you have a Griff).
zumbruk said:
No, 3dB is double. 10dB is 10 times as much.
I remember learning it but it still makes bugger all sense to me! AS long as I get on the track I dont care.
AS for removing baffles.
We did some tests a while ago on a Chim 4.0 without baffles. At 3/4 revs (4000) it was 106db. Max was 125db I think.
Ask Big Al, he'll remember.
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