Track day noise info

[benbunny]

If it helps anyone who is stressing about noise levels........

Yesterday I did a day around Outlon Park in my Puma, it measured 84db on the static test.

I was running a Sportex 4-2-1 manifold (unwrapped), no cat, race pipe and a standard rear silencer from eurocar parts.

Cheers,

Ben.

 

[TGPlayer1]

Those Euro silencers are ridiculously effective. I've got one on mine and without it there was much noise and i fitted it and you can barely hear the exhaust.

 

[benbunny]

They are great. Not too much silencing at full whack though, your head is still nicely droning after 20 minutes. :grin:

 

[JimF]

Just out of interest, how did the Puma cope at Oulton, can be quite a high speed circuit - did it have enough power?

 

[grayfox]

I would worry if I didn't have a central silencer. Run a decat 421 and straight through 3" piper back box, been over 90db on static tests no idea what drive by is but quite a bit more under load up to 7250rpm I'd imagine!

 

[benbunny]

JimF,

It held it's own for most of the circuit, the only bit I felt it need a bit more grunt was down the Lakeside Straight heading into Island bend. The 2 litre cars were pulling away a bit, but you'd catch them up on the second half of the lap.

I'm planning on FRP equivalent cams and a remap which will be enough. Got to get the kid's Christmas out of the way first!

Grayfox: yep, it all depends just how good your back box is. I had a no-name one before i fitted the 4-2-1 manifold and it was just too loud without the centre silencer.

Ben.

 

[PumaJay]

I have a full piper system inc 4 branch manifold and I removed the centre silencer, its louder, sounds awesome and ive never failed a noise test with it yet.

Oulton is a great circuit for the puma but like you say just going down the lakeside straight there isnt enough power to keep with the bigger engines.

 

[grayfox]

Good to know Jay! Might depend what figure is declared to the tester as your redline (or if they even ask) 3 out of 4 times I've only been asked for 4.5k, when 3/4 revs of 6.5k is 4.9k and of 7.25 is 5.5k!

 

[RichPuma]

I have a 421 Sportex too with straight through centre to a Sportex Back Box (4") its passed at Blyton and Cadwell at 5K RPM its loud and makes cats and dogs run for cover!! wouldnt be without it now. getting super chipped soon, just to see what happens to my ear drums, its stripped out too so it resonates through your bones. Love it

 

[RichPuma]

yep its better with a bluefin superchips map put on the ecu. it revs to 7200rpm the midrange pickup is improved, Im not sure its any louder! Iv will know more after Ive been to Blyton Park on the 7th of February :wink:

 

[tractorboy]

One thing to bear in mind is the accuracy of noise measurements at tracks. In my experience many tests are not done exactly by the MSA regs and usually result in low readings. Snetterton seem to know what they are doing but Rockingham and Castle Combe on the days I went were pretty poor. Generally pretty variable. So, you can go to a track thinking you are OK (based on previous tests) and then find they measure properly and you fail the test. I ended up buying my own meter as I knew my RX-8 would be very close to the limit for where I was going. Another issue is that tracks seem to be getting much tougher on drive-by noise levels; recently I've seen more cars getting flagged for this, and at some tracks they operate a one-strike and you're out for day policy.

Bob

 

[RichPuma]

Went to Cadwell on the 21st March and it's blowing 99db at 4,500rpm. Now doing low 1.57 lap times on a busy track. Got to shed some more weight!!

 

[Milkie]

I thought I would add my sound level as it was higher than I thought it would be.

Not many modifications:
4-2-1 Stainless PumaBuild Exhaust Manifold, Wrapped
Piper Sports Cat, Stainless Exhuast (Piper Cat Back System 4" Slash Cut) with Mid & Rear Silencer

Castle Combe @ 1m @ 4500rpm = 96dB
Combe are known to be one of the more stringent noise tests.

EDIT: Have done 2 track days at Combe since and they were 90dB.

 

[PumaThunder]

Good to see what other people have here, at a stage where we need to get ours quieter.

Straight through with Cherry Bomb:
Static - 99
Drive-by - 87.2 (not really really pushing)

This was at Bedford (limits 101db static and 87.5 drive-by), where they are 1 strike and you're out. We had a noise board which means we got within 1db on drive-by.