10th Event - DB Levels....

[BraindG]

Guys,

Without going to much into my plans, cos I may not be able to do it.

Do you know your DB level? - if so, what is it?

I'm looking to do something for our event, but being slammed back with 98 DB limits all over the place..

[Nick Mann]

I was measured at Donnington last year in the high eighties, 87 or 89 I think?

Over 98 is pretty loud, but very possible with no in-line mufflers and/or a very small back box.

[Atik]

My old twin setup was measured at 86dB using an old iPhone app. Havent measured the new one but its super quiet so about the same I would say.

[MarkSanne]

The Kakimoto muffler I had on the Legnum was pretty loud (around 96db if I remember correct). Now I've got a modified stock legnum muffler (it's around 73db now so way under 78db which is the Dutch legal limit). The stock moffler will soon be replaced with a Varex one; loud when wanted, silent while cruising Just need to receive the thing and weld the correct size stainless flanges to it.

[Colin Wiltshire]

Think mine was measured at 96db at Japfest

[aboo]

Mine was 99db at japfest 2010/2011. Still the same set up.

[chris g]

I would guess...

Prob all cars with cat will be under 98...

Cars without cat and larger bore exhaust system may be over 98...

Or something completely different to this....

[aboo]

The only silencer I have on my system is the Jap can back box with a 4.5" exit pipe. I found the down pipes make no difference to how load it is.

In 2010 I had the RPW downpipes fitted but in 2011 I had standard downpipes fitted & got the same result. Combs test is sitting at 3500 rpm.

I do have a bung to quite it down a bit if what every you have planed go's ahead.

[Davezj]

barry,
i have a DB meter so i can do measurements at the next meet if you like.

[BraindG]

barry,
i have a DB meter so i can do measurements at the next meet if you like.

That would be awesome Dave, then I have a good idea whether this is possible, or not.

[aboo]

barry,
i have a DB meter so i can do measurements at the next meet if you like.

Is that the one you had at Japfest a couple of years ago Dave? I remember that one not being very good.

[Davezj]

yes it is, but i realised at that japfest the the measurement is done at a 45deg compound angle so it is from the back about 2 feet left of exhaust and 2 feet up from that point, which makes a massive differencse, which is why my reading were high as i was doing it at just a 45deg horizontally only from the exhaust.

the meter is fine it was operator error at japfest. i duplicated my japfest noise measurement when i got home when doing at a compound angle.
but we remembered the andy.

[aboo]

I only remember cause you had me worried. I remember you were getting readings of over a 100db & when I heard your exhaust compared to mine I didn't think I was going to get on track.

[Davezj]

yes it was a bit worrying.
it is amazing how much difference the extra 45 deg makes.