R400 track day noise probs.
Discussion
I was at a track day at Donnington briefly yesterday until I got chucked off for noise problems on lap 2.
The circuit limit is 98dB and my totaly standard R400 with the standard exhaust and cat on was measures at 102dB!!
It needs sorting, what's the point of having a Caterham you can't go on track days with!
I have spoken to Caterham and they suggest a large silencer and short collector @ £550 and a carbon airbox and scoop at £850, both plus VAT.
So that's £1645 all in!!!!!
So back in the real world I'm looking for suggestions.
I think I'd already decided that Raceco is the way to go on the silencer but what about the induction side?
Any suggestions gratefully recieved.
The circuit limit is 98dB and my totaly standard R400 with the standard exhaust and cat on was measures at 102dB!!
It needs sorting, what's the point of having a Caterham you can't go on track days with!
I have spoken to Caterham and they suggest a large silencer and short collector @ £550 and a carbon airbox and scoop at £850, both plus VAT.
So that's £1645 all in!!!!!
So back in the real world I'm looking for suggestions.
I think I'd already decided that Raceco is the way to go on the silencer but what about the induction side?
Any suggestions gratefully recieved.
I've got the largest Raceco possible on my SLR and I'm just about OK at Donington - sometimes I have to short-shift past the noise meter at the start of the straight.
The R400 may have slightly greater induction noise than my SLR - have you got a cut-out on the bonnet? If so, then I'm afraid some kind of airbox seems to be the only alternative.
The R400 may have slightly greater induction noise than my SLR - have you got a cut-out on the bonnet? If so, then I'm afraid some kind of airbox seems to be the only alternative.
Hi, I too used to short shift at the start of the straight, but the problem at Donnington is that now they have 3 noise meters round the circuit and they are linked to the local council.
The limit is 98dB drive by too so the induction is barking, no bonnet cutout on mine but I reckon the induction is still louder than the exhaust.
You'd reccomend Raceco then?
What size is yours (ooh err missus!)
The limit is 98dB drive by too so the induction is barking, no bonnet cutout on mine but I reckon the induction is still louder than the exhaust.
You'd reccomend Raceco then?
What size is yours (ooh err missus!)
bertie said:
You'd reccomend Raceco then?
What size is yours (ooh err missus!)
I've managed to get on at all circuits I've tried since fitting it, including Goodwood and Castle Combe. It is also repackable, so if it does start to get a bit louder I simply stuff more packing in it. 
I have the 7.25" diameter jobbie - the largest they make I think.
Outrageous piffle; this is one of the reasons why I use sheep for chicanery.
Then again, remember Tomalin's wise words: "it fairly tears the air apart:" the decatalysed option seems increasingly redundant.
I don't remember your SLR's noise, Jeremy, being too preoccupied with basic Newtonian physics at the time!
Then again, remember Tomalin's wise words: "it fairly tears the air apart:" the decatalysed option seems increasingly redundant.
I don't remember your SLR's noise, Jeremy, being too preoccupied with basic Newtonian physics at the time!
This country is so full of bollox and needs sorting.We are run by Europe and do all they say at a wimper.So why on earth can you go to places like Spa and run at 120dbs.Whats the bloody difference between 98 and 108 other than 10dbs.For god sake,after all it is a race track and your not exactly flying 10 feet above someones bloody roof.Also whats the difference between weekend decibels and weekday.It seems that higher db limits are available in the week,that would indicate to me that days of the week now have ears,piffal!Well got that off me chest.
What ruy didn't tell you is that his silencer actually came OFF a 747.
Induction's probably your enemy if you're at full chat.
Have a word with Oilyhands - I believe he either makes, or knows someone who makes, fibreglass airboxes.
The Caterham airbox is both expensive (very) and not free of problems in itself.
It makes my blood boil to see noise limits on tracks like this. People moving near to race circuits know that the circuits are there. If they don't like cars, move somewhere else.
Induction's probably your enemy if you're at full chat.
Have a word with Oilyhands - I believe he either makes, or knows someone who makes, fibreglass airboxes.
The Caterham airbox is both expensive (very) and not free of problems in itself.
It makes my blood boil to see noise limits on tracks like this. People moving near to race circuits know that the circuits are there. If they don't like cars, move somewhere else.
Thank goodness the noise test doesn't measure the overrun from 7,500rpm. 
MSSILLE said:The advice I was given was to repack (or redistibute the existing packing) when you start to see discolouration of the outer cylinder. This generally shows when there isn't much packing to stop the hot exhaust gases.
On a related subject how often or after how many trackdays should you repack a Raceco silencer?
Or do it when you think it sounds louder: it doesn't take very long to pop one of the ends off and check it.
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