Bedford 1st May - 420R noise question

[JAL73]

Anyone on here going to Bedford autodrome next Monday? 

I'm a new owner of a standard 420R with side exhaust - can anyone advise if this should be ok with 87.5db drive by noise restrictions there? 

[L7 FST]

Hi - I was waiting for a 420R owner to reply with some specific comments for you, but in the absence of that here are my thoughts.   I recently attended a Bedford track day where several other Caterhams were present, including an R500D with side exhaust, and everyone seemed to be fine (except me on one occasion, when I was warned I was right on the drive-by limit in my 2.3 Duratec).   If you do get a warning at Bedford, they normally tell you (or hint at) which part of the circuit is the problem, and it's pretty easy to avoid further trouble by moderating the revs slightly at the crucial point.  In my experience the MSV staff there are very helpful and constructive.

Have a good day and hopefully the weather will be good.

Stephen 

[graearea]

I go there in my R400D.

after the first hairpin after the pits, shortshift until you're past the poles that look like they might contain a microphone and a camera.

around the back of the track if you're on the full circuit, before the really tight hairpin, just before the marshalls post there's some things that might look like they contain microphones and cameras, be careful about blipping downshifts and being near other noisy cars here. otherwise, you should be fine. I passed with a stock exhaust and then got black flagged on full throttle. I was asked to fit a bung.

 

tl;dr keep away from noisy cars, don't make noise near the mics.

[ChrisC]

My 420 had no noise problems at Bedford, side exit with or without cat, standard plenum and airbox.  
 

[JAL73]

Thanks for comments. I bought a decibel slayer from Sevens and Classics just incase but it wasn't needed in the end! Some of the tracks I have planned for later in the year are also restrictive on noise so it might come in handy one day.

I'm considering getting a rear exit exhaust as Im not keen on the breathing in exhaust fumes, tho not sure if they are from my car or other surrounding traffic!? Also, quiet like the look of them

[SamC]

I'm planning on going there soon in my CSR and have the same concerns you had. Did they do any static measurements? If so, did you try to measure yours with a smart phone etc before you went?

[JAL73]

They told me to rev to 4,500 rpm and mine was at 90db.
I was also short shifting more than usual as track was damp due to intermittent rain.
My car is a 2020 with 2.5k miles so maybe the exhaust packing is still pretty good at keeping it quiet, there were some other 420s there a bit older than mine which were a bit louder, and have heard that other 420s have been black flagged for noise in the past, so it seems a bit random or down to fine margins.

Im probably going to switch to a rear exit exhaust for reasons other than noise soon - I'll sell my decibel slayer (only used once on road for 20 minute test run!). PM me if interested.