Worried about noise - Goodwood track day

[mr-ed_smt]

I have a trackday at Goodwood on Friday with a 98db static noise limit. I'm a little worried as to whether I'll pass. I have a markii pipe, TOMs panel filter, Che-style manifold, and a Remus twin (rest of spec as per my sig). I did a test (admittedly with a crappy iphone app) 50cm from the exhaust tip at 3/4 max revs, and I got about 98-99db  s:? :? s:?  .

The last time I did a trackday I didn't have the Che manifold (just a de-precatted OEM) and scored 96db (when hot). I have read the sound levels thread in reference, and everyone else seems to have sound levels much lower??

I'll take the standard manifold and a toolkit with me just in case I fail, but would rather it didn't get to that!

Any idea why mine is so noisy, or what I could do to easily and quickly quieten it down  s:?: :?: s:?:

[Slacey]

We (the TVRCC) had a track day there just this weekend, although with a 105 limit - not a single car failed, even the GT series race car. I've never seen a circuit where the meter under-reads so much! I think it's mostly due to them using a wide open space to test which helps enormously. I wouldn't worry too much.

[mr-ed_smt]

Thanks Slacey - set my mind at rest a little, although it was at Goodwood also that I scored 96db (without new manifold). They seemed very strict - checked every car instead of a selection. Last day was run by GRRC, and my one on Friday by Motorsport-Event if that makes any difference.

Would there be any reason my car seems to much loader than other cars of similar spec?? I get a lot of popping/crackling from the exhaust on lift off/overrun, which I love (99% of the time!) but could this be an indicator of an exhaust leak?

Is there anything I can do to quieten it down? I have heard that wrapping the silence with exhaust wrap can reduce the reverb a bit? Other suggestions have been wire wool up each tip!?! Not sure I like the idea of that...

Pretty nervous about Friday as it looks to be my first trackday in the wet...   s:? :? s:?  !

[DannyN]

First trackday in the wet is no bad thing as the rain will help you err on the side of caution and will help you sto stay concentrating / not get complacent.

Have fun

[Don of Croy]

When you're on the track (or on the road) in the wet, have you noticed the stability control yet?

I'm still waiting to see it intervene - although I'm so lacking in cojones I'm keeping the speeds well inside my small envelope of talent...

[Anonymous]

something up the exhaust it always works. i use to work on a rally car as a mechanic (not pro b4 people ask) but the cossie that we were running was about 10 db over the limit. so off came the sleaves from my overalls and up the exhaust they went, and we got a pass on the db meter. Was good before the first run tho, driver stuck the antilag on and short my overall sleaves out the back in lovely fireballs.

[mr-ed_smt]

When you're on the track (or on the road) in the wet, have you noticed the stability control yet?

I'm still waiting to see it intervene - although I'm so lacking in cojones I'm keeping the speeds well inside my small envelope of talent...

I have fully explored the capabilities of the VSC and TRC! (although I'm not entirely sure what that says about my driving  s:? :? s:?   lol!)

When the TRC cuts in (ie to stop the rear wheel spinning) the warning light flashes on the dash. Then the VSC cuts in (ie when its detects the car is starting to spin) the light flashes and you get a loud audible triple-beep. Either way it is very obvious when either cut in (its fairly rudimentary I think).

The VSC is fairly effective at stopping power-induced oversteer - its will catch most "accidental" power-oversteer. However if you deliberately provoke it - ie keep your foot in on a wet roundabout - it WILL NOT stop you spinning. Equally it is entirely ineffective against lift-off oversteer - particularly in the wet.

To summarise, its no substitute whatsoever (obviously!) for keeping the car balanced, well maintained and on good rubber, and driven within your ability (particularly in the wet). I've had two accidental spins in mine (in 35k miles) - both in the wet. One at high (motorway) speed caused by excess speed on a bouncy sweeping corner, and the other at 20mph on a small round-a-bout, caused by me sharply lifting off at the first sign of understeer - car immediately swapped ends!

[Don of Croy]

Cheers - appreciate the reply!

Makes you wonder when it can swap ends at low speeds - would you say the road was especially greasy that time? Low tread on rears?

I'll have to move somewhere without bends - Lincolnshire perhaps.