Noise...

[Bibs]

Rather than changing my exhaust system entirely is there a way I can drop my noise level from 114dB to less than 105dB, any tricks?

Thanks guys

[Adam43]

Less revs?

Insert a silencer in the system, maybe even just at the end. There are plenty of boxes available from from places like Demon Tweaks and local car spares places. Although we've been lucky and never had to do this, normally we've just removed boxes and still been under the circuit sound limits.

[Bibs]

Sorry, I perhaps should have said I'm after a temporary solution, kind of a bolt on if available rather than a permanent change.

It's for a one off trackday, I just thought some of you folks would be experienced with such problems yourselves...

[Adam43]

What car is it?

[GORDON STREETER]

The SVA test is 101db and most road cars are supposed to be 89db. Although the police haven't any official testing equipment for use beside the road (that I know of)
As most of us that have had race cars for years will know , that the db level will alter from track to track depending on several variables, including the position of the vehicle and the operator of the meter.

[Adam43]

So, park further away from the tester

Probably a silencer bolted on to the rear of the exhuast. You can always sell it afterwards, or do your neighbours a favour and keep it on

There is no point is a really short term fix for just the test, most track days have sensors around the track and will black flag you. Which will annoy!

[andy robinson]

you can buy various temp reducers/silencers from tweeks, ive used these's in the past
http://www.demon-tweeks.co.uk/produc...ode=JETU935130
or
http://www.demon-tweeks.co.uk/produc...de=MSD344-1705

or for a proper fix get a repackable silencer

[GORDON STREETER]

Agreed on that Adam its an ageism thing and its difficult to put an old head on new shoulders. Most MSV tracks are 105db with the Brands GP loop 101.

[Bob Pearson]

I have a couple of early Formula Renault stainless steel silencers knocking about in the workshop for a modest sum if you want to pm me.

[Stephen Green]

BiB's runs an early Lotis Esprit and having followed him home a week or two ago I can confirm it is way above the noise level for track days.

[Bibs]

Those Demon Tweeks one's could be the ticket. I can get a stock exhaust from Lotus but would rather avoid the hassle of changing it, thanks

[Adam43]

I'm impressed that you have managed to get an Espirit that loud. Fair play!

[Al Weyman]

I have used and still have Supertrapps and yes they do work and have the advantages of (a) You can stick them on the end of the system, and (b) You can adjust by removing or replacing discs to get the level correct. The down side though and this is a definite despite what they may tell you and that is you will experience a loss off horse power.

[JamesH]

You could buy a old race motorbike silencer and bolt that on. They are pretty big bore and straight through. Usually some on Ebay at sensible prices (<£50)

[AndyV]

You could try one of these
http://www.merlinmotorsport.co.uk/p1...duct_info.html

But in my experience Bolt on short cans (and I suspect a supertrapp will be similar) will only give you around 3db reduction, max 5db it you're very lucky. I suspect to get from 114db to 105db a decent size silencer is required. You could try a fitting 90degree bend to your tailpipe then a silencer athwartships across the back end of the car.

http://www.merlinmotorsport.co.uk/p1...duct_info.html

I've seen this done on a Castle Combe trackday car before. Messy looking but less expensive than the alternatives.

Andy

[CNHSS1]

have a 'downturn' on the exit of the tailpipe, will often help the nosie testing device 'hear' a lower level, but only by a couple of dB generally

[Bibs]

Originally Posted by AdamAshmore

I'm impressed that you have managed to get an Espirit that loud. Fair play!

http://uk.youtube.com/watch?v=c-Li-vWLeNU





Sounds lovely too, not just loud and you can hear the turbo blades spinning. No cat and Quicksilver SuperSports exhaust. It's arousing!

[AU N EGL]

Originally Posted by Bibs

http://uk.youtube.com/watch?v=c-Li-vWLeNU





Sounds lovely too, not just loud and you can hear the turbo blades spinning. No cat and Quicksilver SuperSports exhaust. It's arousing!

That is not NOISE, that is Music.

Now that quicksilver car should have started its engine instead of just roll. No noise. What a waist of a sports car, no noise.

[Adam43]

Brum Brum Brrrrrrruummmmmm.

[JohnD]

Buy/make a 'decibel insert'.
Tube that's a sliding fit inside the exhaust pipe end; tube inside that with wire wool packing between them. Fix in permanent tube by a big self tapper. Needs to be about nine inches long.

So cheap to make, that you can experiment with the relative inner and outer insert tubes and the amount of packing. Yes, you'll lose power, but it's only a track day.

John