Trackday Noise Exhaust Advice Needed

[Beaniemoo]

Hi there, although it's Sunday now so there's not a lot I can do about it I thought I'd ask on here as there's a good few trackday warriors about. Had the throttle bodied F4R engined MK1 sound tested yesterday and it's MEGA loud at 109db static! At the moment It uses a custom made powerflow system which consists of a straight through centre section onto a single backbox. I can obviously get a centre box put in it but I have no idea how much thats likely to reduce the noise by. Does anyone really know exhausts and could give me an idea of what it'll take to quieten the car down enough to do my trackday at bedford autodrome week after next?

Cheers. Chris

 

[chrispy.clio]

Was it 109db at 3/4 throttle with the DB reader 1meter away at 45degrees to the exhaust? Thats how they test you and the reading can be higher if its not at those angles and distances.

The only advice i can say is that my exhaust http://www.k-tecracing.com/show_product.asp?id=2419&catid=8&appid=2&pic=2 is 4db quieter at 4,500rpm and 6db quieter at 6,500 by having a small center silencer.

I would get one slightly bigger than you think you need to be on the safe side. Then at least you still have the Brawp from the ITB's to keep you happy if the exhaust is a bit quiet

 

[Tony Hunter]

They are fussy at Bedford,even if you pass the test there are noise meters around the circuit and induction noise will set these off also.

 

[Beaniemoo]

That doesn't sound very promising at all as the 48's create a hell of an induction roar at full chat. As luck would have it my dad works at bedford and is my passenger for the day so he said if we have trouble then we can lift a little past the sound moniters.
The sound test was done at the right distances but I had to hold it at 5000rpm as the car revs to just over 8k. Just hoping getting a centre section fitted really brings the noise down a lot.

 

[Fred@BTM]

don't tell them its max rpm 7000 is all they need to know

we had to drop the rev limit to 6K for bedford

 

[172Ben]

As above, i told them(oulton) my limit was 6500 But as said, bedford have noise tests all around.

 

[chrispy.clio]

When i first went to bedford on my very first few laps i was hitting the limiter all over the place (got a bit excited). When i came in they told me i was right on the limit, nearly setting off the sensors round the track and they told me to change early so i didnt set them off. As its one strike and your out.

I then just drove round the rest of the day not hitting the limiter and changing where i should and i had no problems.

Get the centre silencer but just take it easy and see what they say. Might be fine

 

[Fred@BTM]

i was 100db @bedford limit was 101db just got on

 

[jenic]

Anyone who buys a house near a track should be forced to stfu. If you dont like it move (exceptions only to people who lived there first, once everyone is newer than the track then its tough s**t).

 

[Stu_182]

Sounds well harsh on regs down in England. I did a track session at knockhill and they never even checked the noise limit.