BTB exhausts

[GetCarter]

Hi,

 

Some advice from any in the know please? Thanks in advance.

 

I have an R500 due for delivery in a few months and due to the fact that Caterham tell me they can only get the db down to 108 by fitting their silencer, am probably going to get BTB exhausts to fit one that they assure me will get it below 100 db. (With, they say very little power loss).

 

This will open up most of the track days that I like to do.

 

I know a few of you out there have gone a similar route - Have BTB done what they say on the tin?

 

Or if anyone else has followed a different path - I'd ideally like to have the car adjustable between 'normal' and 97 db (which would get me into all the track days I currently do).. assuming I fit an airbox for 'drivebys' (Good move I presume?).

 

Ta

 

Steve

[Andrew_Bailey]

Steve, did you get the BTB exhaust and if so what sort of noise level do you measure with the airbox fitted as well? Caterham seem reluctant to supply rear exit exhausts and are now suggesting their new (no quite available) 7" repackable side exit exhaust. I need to have a system that I can be confident will consistently be below 100db. So far as I have been able to tell by reading past postings and talking to a few people, the only way of doing this with an R500 has been with a rear exit and carbon airbox. Any thoughts would be greatly appreciated. Andrew.

 

C7 OCU

[murph7355]

Can't give definitive figures but quite a few guys are running the big BTB cans with good results. I'm certain they're now below 100db with the airbox and this can.

 

When I asked I think there's a 3 week lead time. If you buy one, let me know as I might invest too (though I love it noisy) and we might get some wedge off.

 

 

 

 

[Andrew_Bailey]

Andy, do you think that the new 7" can that Caterham are talking about is actually the BTB product? They gave me the impression that this was a Caterham product.

[F355GTS]

I'm sure Steve will be along soon but he did get the BTB and I have one as well. On his R500 with airbox he's about 101 dB static but i don't know if this is at true 3/4 revs, my VHPD is circa 102dB at 5,400, at 6k it's about 104db, don't think it needs repacking but might give it a go.

 

Steve has now arranged to have his BTB extended

 

Mark

[murph7355]

My guess would be not. But I could be wrong.

 

Having read a few posts from earlier in the year I believe that they are 400+VAT but that BTB are open to discounts for 2 or more (I heard 350+VAT).

 

 

 

 

[murph7355]

Further to Steve's note, I think there might be two or more variations of the BTB silencer.

 

The one I've seen (on Richard Ince's car) could house small children quite comfortably.

 

Graham's rear exit set up seems to work though.

 

The BTB ones also need frequent repacking AIUI.

 

 

[GetCarter]

So...

 

I got Joe at BTB to fit the silencer (much lighter than the standard one :-) - and the reading when newly packed was 100.8 @ 6000 rpm@ 1/2 metre. (so very nearly 3/4 revs). Then got another test (on a track day) that put it at 101.2@ 6000@ 1/2 metre. (but there was a building about 10 metres away).

 

Caterham fitted the carbon airbox and at 20 metres flat out (and I mean flat out!) it reads 99db. This means I'm just over Bedford's noise limits and very close to others that I like to do... so:

 

Next week I am having the longer silencer fitted by BTB, which will (I'm told via BTB from R500 racers) get the noise down at least another 1, possibly 2 db - without any power loss (they say).

 

I'll let you know.

 

The other option (which I nearly went for), is Roger King's 7" 'Goodwood' - - but don't know how quiet this is.

 

I'm back from hols on 18th Oct - will post as to how quiet the car is then.

 

 

 

Steve

R500.COM

[David Ward]

I have a long BTB can on an R500 manifold on my much modified 1.6K. This has brought it down to about 101dB from 106db(standard Titanium R500 can) @5800 - as always the readings vary a lot from place to place....

 

I don't have any airbox system fitted so I guess that makes a further difference.