Cerbera 4.5 - What DB is the standard exhaust normally?

[Rawhide]

I'm considering bedford trackday next weekend. I've been there before so know they are tight on noise. Their limit is 101db.

Has anyone tested their car with a standard setup and been under that?

I know they have drive by points as well.

[N4 FTW]

My decatted 4.2 with the rest of the exhaust standard just sneaks under at Bedford, around 100dB. Passes all of the drive by tests no problems at all.

With cats on it would be quieter still (but rather warm in the cabin I would suspect!)

[ukkid35]

Rawhide said:

I'm considering bedford trackday next weekend. I've been there before so know they are tight on noise. Their limit is 101db.

Has anyone tested their car with a standard setup and been under that?

I know they have drive by points as well.

I have a 4.5 with Sports Exhaust and Cats, I just scrape by on 105Db days when I declare a 6k redline. I seem to get tested at either 4k or 4.5k, which makes a big difference. Whatever happens on the static you can always get caught by the driveby, so it's worth short shifting anyway if you know you are going to be close. However, I doubt you will get past a 101Db static without track day silencers.

[grahamn]

Rawhide said:

I'm considering bedford trackday next weekend. I've been there before so know they are tight on noise. Their limit is 101db.

Has anyone tested their car with a standard setup and been under that?

I know they have drive by points as well.

If it is standard with the cats in, you should be alright at 101db. Mine made it under the 98 limit there with a standard set up.

[Tanguero]

I run a decat with a standard back box and scrape in at 101db at most noise checks so I thin you may be borderline. Rather than get chucked off on a driveby test and loose the price of the trackday I would stick some external cans on.

[Rawhide]

Thanks guys, I might have a solution with UKkid35 for a loan set of cans to have in the boot.

[Alistair H.]

I am standard set up and static is 99Db.

Drive by is a bit different though. I am marginal on 95Db drive by and need to keep the revs down to avoid failure.

If drive by is your only measure you should be OK if you keep below silly RPM, or drop the revs if you know where the drive by measurement points are.

[GT6k]

Mine is completely standard and it was 96-97db at I think 5k rpm last time it was noise tested (at Castle Combe)

[Byker28i]

Standard exhaust system (TVR big box) is around 99db with the cats in. The cats take 8-10db off.

If you're really worried, act do some trackday silencers with take 8-10db off. Might be worth having or borrowing some just in case?
http://www.actproducts.co.uk/silencing/trackdays/

[Obiwonkeyblokey]

GT6k said:

Mine is completely standard and it was 96-97db at I think 5k rpm last time it was noise tested (at Castle Combe)

The same, 96 at combe on a standard 4.2. Now 109 with sports cans.

[Mr Cerbera]

I was measured at the Ring once (Phnaaarh, Phnaaarh) and was told that I registered 108db - Totally standard.

"It's never the measuring tool. It's the tool measuring it."

[ukkid35]

What a great day at Bedford - thanks Neil!

[Rawhide]

ukkid35 said:

What a great day at Bedford - thanks Neil!

Good to have you along Paul.

BTW - the standard 4.5 tested 98db at the static at 4k RPM. I didnt get black flagged on the circuit.

Cerbera performed well, if not perfect. Boiled clutch fulid and a sticking throttle stopped play but that was after most of a day of moderate track driving.

Edited by Rawhide on Monday 28th November 12:58

[Mr Cerbera]

"Boiled clutch fluid"

[ukkid35]

Mr Cerbera said:

"Boiled clutch fluid"

Wasn't too scary, pedal pressure returned within five minutes, braided hose probably too close to the exhaust manifold, plus old fluid - easy fix.