Trackday silencers for bike-engined cars

[Gruffy]

What's the most economical way of temporarily silencing my exhaust for a track day? I had been looking at clamp-on silencers but the flared pipe on my car is too wide (3" dia) to accept anything I've found. The pipe points downwards a little and is also quite close to the outer width of the arches, so any clamp-on solution needs to be really compact.



Are there solutions out there or do I need to swap the whole can?

[xRIEx]

A lot bike exhausts have the option of baffles/dB killers inserted in the end Google images for dB killer. Some silencers are supplied with them from the manufacturers, there are aftermarket versions that have varying levels of success.

[Gruffy]

Excellent. If I can find one that works well that'd be perfect. Any insight as to those that perform better? I imagine there are plenty out there that are next to useless.

[Jon Ison]

DB killers should also be renamed BHP killers, avoided if at all possible.

Does your silencer need re packing, how long since it was last done, is it big enough to quieten the engine sufficiently ?

Since I re packed mine with this track-day noise problems have been a thing of the past.

[Gruffy]

I've just ordered myself a noise meter so I can find out exactly what I'm dealing with. I very much doubt it's been repacked ever, but it's only covered 3,500 miles.

[Russ Bost]

I use 2 x Db killers in the exhaust on the Furore with no noticeable loss of performance (mind you it's not exactly restricted, it still has 110Db @ 8000rpm, I need to add an extra silencer for trackdays!). A Db killer is only going to reduce sound significantly if the gases have somewhere to expand into, your can looks like a reasonable diameter so stands a chance of working fairly well.

[Furyblade_Lee]

I have falllen foul of the noise meters at Zolder, which is a long way to go to get booted off.... :-)

So I have my "spec Zolder" tailpipe, which is cunning in that is is a chopped off version of what you have but twisted down so the gasses exit just to the inside of the rear wheel directly at the ground. It certainly helps a bit as my R1 was shooting flames and bangs directly at the noise meters. Firing them into the road takes the edge off, but it is not an ideal solution. It is still 100db drive-by and as we know, that will sometime pass a 98 or foul a 102 dependent on the day, weather, track and god knows what else.

In all honesty i have concluded that I cannot ever comfortably get my R1 under 100db so I choose not to go anywhere with a low noise limit. I am sure most of the noise is induction noise so I cannot do much about it, despite a sealed intake which sucks from below my front headlight. And I have never heard a "quiet" BEC, if
anyone has worked out how to get
them genuinely below 98 without strangling the life out of them please let
me know!!!

[Furyblade_Lee]

Sorry, I sm viewing this on an iPhone and because somebody mentioned a bike can I assumed ( maybe wrongly ) you had I bike engine! What do you have??

I heard once somebody blew up an M3 and blamed a Supertrapp bolt on thingy, but not sure if it was true.

[Gruffy]

Yes, it is a bike engine. It's a Blackbird.

[BusaMK]

Are you using an airbox? Putting a reverie on my busa engine rather than the usual foam filter made a big difference...

[Gruffy]

Yes, it has an airbox already.

[one eyed mick]

Do not use'regulators ' if you want 1 to keep power 2 if you want to keep your engine they kill both not to mention over heating etc

[pikeyboy]

Furyblade_Lee said:

Sorry, I sm viewing this on an iPhone and because somebody mentioned a bike can I assumed ( maybe wrongly ) you had I bike engine! What do you have??

I heard once somebody blew up an M3 and blamed a Supertrapp bolt on thingy, but not sure if it was true.

My caterham fireblade was tested at oulton 98 static with a 7.5 dia can thats as long as possible. It also has an offset inlet pipe. I use a paper filter and no airbox. You can make bike engines low noise just needs some thought.