Silencers

[erictharg]

I'll not know what the noise level is until the next race but the stock Jetex oval silencer I've fitted looks the part and sounds a lot easier on the ear than the factory item. The all black system looks more period than the stainless item, and will need replacing for sound reasons long before it rusts! About £45 and 20 mins to weld a bracket onto it that picks up on the stock mounting, and and angled outlet. If it gets me below 105 I'm happy!
It has a 7" x 4" oval profile that makes the most of the space. If it were a little longer it would be even better. It's about 18" vs the stock 20". If you could find something similar but say 24" long that would be perfect.
I was quoted over £200 for a custom made 5" round x 24" long design. I dealt with some guys at Klarius a while ago - might give them a call and see if they have anything similar in their catalogue of designs..

[jonclancy]

Brilliant, please let us know how you get on, Charles.

I'll see where we are in a week or so, then collate and forward any replies / orders / suggestions to Simon.

Perhaps he's right and there is only a couple of us that this issue affects...

[Mknight702]

I have tried to dismantle my silencer(like Charles did) but mine wouldn't come apart. I ended up going to Custom Chrome and they said that the silencer was non dismantleable (well I tried and couldn't)! They made an insert that sits inside the standard perforated pipe and has two or three baffles. It seems to have helped, I didn't get pulled for noise at Barkston but then it's 105db although a Duratec car got queried. Best bit was it only cost £35. I do have a noise meter but I haven't tried it out yet.

[jonclancy]

Thanks for the info, Matt. With your 105dB limit at Barkston, this issue seems only to affect Charles and Me.

I may drop MSE a line and ask about a lower rev testing point based on my lower max revs.

I'll let this run for a few more days and then get back to Simon at the factory.

Cheers

Jon

[Mknight702]

It wasn't a problem for Barkston, but it would probably stop me from driving at any other track. It would be nice to have a little more choice!

BTW, I saw Scorpion exhaust on a bike here at work and the can looked remarkably similar, if the exhaust is from a BEC could this be the source?

[jonclancy]

Could be - any chance of some details? Simon didn't mention the OEM supplier.

I'm wondering is this is really an issue to work through in developing the W11, or a just glitch for the few of us that track the cars...

[jonclancy]

It seems that this is an issue for only a few owners who track their cars - and the limits vary by venue (100 - 105dB).

Thanks for your thoughts and comments on the various forums/lists. We'll look to limit our noise by other methods, and I'll let Simon know that.

[erictharg]

I can confirm that the Jetex oval silencer gives just the same noise level as the factory silencer. 105.4 dBA yesterday at Mallory. Yes sir - I'll get it fixed for next time - honest.
Going to try a baffle design I have in mind to see if I can bring it down a little without adding too much back pressure. Will let you know how it goes.
The kit car in front of me was 97 dBA! Pretty massive 7" dia x 24" long silencer though.

[jonclancy]

Ouch!

I have confirmation that a baffle cone has, in some cases, supplied to get cars to the legal limit for SVA / IVA. The factory are contacting the OEM for pricing / availability. One US builder got a cone in his kit. TonyL has confirmed that No 42 didn't have one when he built her.

[Westfield 129]

I didn't get one with my kit, but I did get two clutch discs for the T9, and three speedo cables.