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How Loud Is A BEC compared to a CEC?
mark_mcd - 11/2/07 at 11:06 PM

As the title states really! How quiet or loud can you make these things? I presume they can't be that bad since they have to pass SVA? Anyone use one on the road and does reasonable miles?

Confused but excited. - 11/2/07 at 11:10 PM

A bike engined car, will be about as loud as a bike engined bike, if you use a bike engine silencer.

Seriously it all depends on the engine/can combination.

[Edited on 11/2/07 by Confused but excited.]

OOoooh look, my thousandth post and Chris has only just realised I'm a freak!

[Edited on 11/2/07 by Confused but excited.]

Even though I've been a contributor since 17/10/2006! But I've given up on that.

[Edited on 11/2/07 by Confused but excited.]

bigrich - 11/2/07 at 11:12 PM

i found induction noise to be worse than the bike race can
my new build will have a standard airbox fitted to lessen the noise
in theory you should be able to make it as quiet as a standard bike with a road legal/standard silencer

Bob C - 11/2/07 at 11:39 PM

mine is R1 engine, R1 can & pipercross type foam filter. It passed the SVA noise test.
I took it out briefly today. f*** me it's loud...
Bob

Simon - 12/2/07 at 12:50 AM

quote:
Originally posted by Bob C
mine is R1 engine, R1 can & pipercross type foam filter. It passed the SVA noise test.
I took it out briefly today. f*** me it's loud...
Bob


As the examiner said on my test "101db hurts my ears, this doesn't"

My cec (R V8) had homemade silencers 5" dia (and approx 15" long) with 2" pipework and perforated pipe inside cans.

Remaking all in stainless with additional silencing (turbos)

ATB

Simon

chockymonster - 12/2/07 at 01:29 AM

My Bec went through SVA at 97db (off the top of my head) Rattles are a big killer!

smart51 - 12/2/07 at 08:13 AM

It depends on what silencing you for to your exhaust and inlet. In general BECs are louder than CECs simply because they rev louder. In practice, the straight cut box adds a bit of whine into the inlet roar and exhaust bark.

If you fit a big silencer and an airbox to a BEC, there's no reason why it can't be as quiet as a CEC. a CEC I knew was once measured at 123 dB(A). Strangly, I K&N filter instead of a foam filter reduced the noise quite a bit.

My BEC measured 101 dB at SVA on an R1 can and measured 102dB at Elvington on a 6"x 26" straight through can.

zxrlocost - 12/2/07 at 09:27 AM

its all to do with the CAN

standard bike can sweet and quiet

stripped out Micron you will be deaf but thats what I like

ChrisGamlin - 12/2/07 at 01:52 PM

Don't forget though that the Db ratings on bike cans are for a specific drive-by test for road bikes and thus completely irrelevent to the tests a car needs to go though at SVA or at a circuit.