IDEAS HOW TO REDUCE EXHAUST NOISE
Discussion
Hi all
Im looking into ways to reduce the noise level on my car. I do not think it will pass any noise limits at track days. Car is a westfield megablade using westfield manifold and silencer.
A friend of mine has a megablade and says he gets 106db.
Obviously i would like to get this sorted before attending any track days, can anyone advise?
Will i need a bigger silencer, if so any reccomendations on model and costings would be appreciated.
Adrian
Im looking into ways to reduce the noise level on my car. I do not think it will pass any noise limits at track days. Car is a westfield megablade using westfield manifold and silencer.
A friend of mine has a megablade and says he gets 106db.
Obviously i would like to get this sorted before attending any track days, can anyone advise?
Will i need a bigger silencer, if so any reccomendations on model and costings would be appreciated.
Adrian
Adrian,
A bigger re-packable silencer will help alot, although some of the noise will be induction noise too since the Megablade runs a open foam filter (rather than an airbox). Another issue is panel resonance, which can exaggerate the noise.
With regard to the silencer, apparently a good trick is to have the perforated tube slightly tapered, as I this makes better use of the packing along the whole length of the can.
A decent replacement can will cost between 150-200 thru to 500 for a titanium one. An alternative is to use a modified (to fit the car) bike can as these are fairly quiet - the Yamaha R1 can is a popular choice for this.
Might be worth buying a budget sound meter to allow home testing for comparison between cans etc.
Dave
A bigger re-packable silencer will help alot, although some of the noise will be induction noise too since the Megablade runs a open foam filter (rather than an airbox). Another issue is panel resonance, which can exaggerate the noise.
With regard to the silencer, apparently a good trick is to have the perforated tube slightly tapered, as I this makes better use of the packing along the whole length of the can.
A decent replacement can will cost between 150-200 thru to 500 for a titanium one. An alternative is to use a modified (to fit the car) bike can as these are fairly quiet - the Yamaha R1 can is a popular choice for this.
Might be worth buying a budget sound meter to allow home testing for comparison between cans etc.
Dave
Has it always been as noisy as it is now, or has it got louder without you maybe noticing over a period. Reason I ask was mine was fairly loud and I just repacked the standard silencer and it quietened it down a lot. I wasn't aware the packing in the silencer was getting burned out - gradual deterioration I guess - but there was maybe only 25% of the wadding left. Took 2 'packets' of wadding from Demon Ts to fully repack.
WB
WB
Being a Westfield owner too with excessive noise,er 115 db um...Have been looking into a replacement silencer as the standard Westfield is not a good track friendly thing,never has been.Have a search for Powerspeed in Kent and Wunoff in Leeds,there's also Techcraft in Banburyish way.I have spoken to Powerspeed who will make up a repackable silencer to my requirements and the pipe to the manifold with all fixing brackets etc for £200.This comes with a lifetime warranty too,so good value for money.Have a look at their website,they have some Caterhams on there with their silencers showing the quality of workmanship.
Try www.powerspeed.co.uk and it will be quieter because of the size of the silencer they can build instead of your 4 inch can,6 inch will be on my shopping list.
You could try Raceco www.raceco.com . I have one of their repackable titanium silencers on my Caterham and it brought the noise down from 105 dB to 96 dB. It is also v. light and looks very good too. If you ring them, ask to speak to Ammo.
Mind you, they're not cheap
Mind you, they're not cheap
Raceco make superb quality cans and a lot of guys in the Seven owners club have got them. They drastically reduce noise and don't significantly affect power. The guy who makes them Ammo does flow bench testing for the likes of the Rizla-Suzuki BSB team and has worked with touring car teams.
His silencers are very well made, light and quiet. They aren't cheap but nor is turning up to a track day and getting sent home after failing drive by!
His silencers are very well made, light and quiet. They aren't cheap but nor is turning up to a track day and getting sent home after failing drive by!
). Static tests have never been over 90dB.cashy said:
YES elvingtons ok but a trek from here in staffs, oulton anf donny are close though and they are 98db drive by.
Oulton is 105dB static, with no formal drive-by (apparently only pulled if you're appreciably louder than other cars with same static test). Also worth noting that if you give them a ring in advance, you can drop down to Oulton when there is another trackday on and they'll noise test for you.If your can is repackable, Acoustafil gets some good write-ups (I'm thinking of getting a couple of rolls as part of my trackday toolkit as, at 6k rpm I'm right on the limit).
Just to add another name into the mix: Simpson. Also in the "not cheap" camp, but again highly regarded.
ETA: Maplins had some sound level meters on offer recently - admittedly not the sort of thing you use everyday but may provide a way to get a rough indication of noise level without going all the way to Oulton/Donny.
Edited by LooneyTunes on Sunday 11th September 07:19
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