Drive by noise limits....Bedford?

[SimonR300]

Has anyone been to Bedford and not been black flagged for drive-by noise?

I was there on Saturday in a road car and was surprised at the number of cars being pulled in and spoken to.  I hadn't realised that they photograph the offenders too. 

I saw a couple of Caterhams get pulled in.  The Academy cars seemed to be ok, it was an R400 and Aurélien Chevalier's Superlight 20 that were close to the limit I think.

I'm going back in May with my 175hp Duratec R300 which has a standard 7" silencer and separate cat still fitted, plastic plenum and airbox.  It passed at Castle Combe with a 98dB static so will pass at Bedford (101dB), but the drive-by (87.5dB) may be an issue.

Caterham don't seem to have any off the shelf solutions to noise and no longer stock the 485 rear silencers apparently.  I spoke to BTB Exhausts who make the rear silencer with central outlet for the Palmersport Caterhams, but they run on gas so perhaps have more room under the tank.  The guy I spoke to also runs a Caterham Cosworth and he fitted a rear silencer finding the rear outlet helped with the noise meters which can be on both sides of the car/track.

I don't want to run into any noise limits at any trackday really.  It seems the favourite choice is Raceco, but has anyone got some recommendations for a rear silencer?

Simon

[ChrisC]

Never had a problem with my Sigma 150 decat.   I also took my 360R last year, however for most to the day I was short shifting near the sound meters, only at the end of the day didn't bother and again no black flag or noise board. 

I have seen 420R Bedford videos on youtube, so it must be possible. 

 

[StevehS3]

I haven’t been flagged in my 120hp K (perhaps unsurprisingly) but there was a R400D that was getting flagged on the drive-by.

[ChrisC]

Do you know if the R400D has throttle bodies? 

[StevehS3]

Sorry I don’t know but he told me it was right on the limit. He backed off slightly and finished the day on track.

[SimonR300]

Thanks for your comments so far on your experiences.  My conclusion is that Caterhams are generally black-flagged unless they back off past the noise meters.

I've heard back from Caterham Parts who suggest I get a new collector, silencer, link pipe and 620 rear silencer which would be about £1700 I think.

I'd like to have a car that I can take to all trackday venues without having to lift off at the meters.  The limits can only get worse so whatever I spend on a solution needs to be well within current noise limits.

I'd like to hear from anyone who has a rear exit/silencer to know which route you took and your success or otherwise.  I'm not keen on the rear U-bend link pipe which seems to get very close to the ground.

I found this photo of a 620R pipe which seems an improvement....

But it doesn't have the silencer....

I rather like the twin rear exit silencer found on some EU cars.

[ChrisC]

I haven’t been black flagged yet at Bedford, but now my car has 420R spec it might happen.  If it does I will be looking at a Raceco silencer before the CC rear exit setup, mainly because it can be repacked, unlike the CC item.