Noise test's

General General Lotus Talk
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Just had a visit from Steve Butts complete with a calibrated noise meter so we put it to some good use [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]My 220 Bhp with SCRP and Eliseparts exhaust was 105dB at 5,600 rpm [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]Trudys 190 with CRP and Janspeed was 112dB at 5,600 rpm [image]http://www.exiges.com/ubb/NonCGI/images/icons/blush.gif[/image] [image]http://www.exiges.com/ubb/NonCGI/images/icons/frown.gif[/image]Steve’s Elise with a prototype exhaust (which Owen at Racespeed is trialing at the moment) was 99db at 5,600 rpm [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]For comparision my daughter’s scream was at 114dB and a train passing through a level crossing in the village was 110dB. Test conditions were not ideal as the cars were tested at the front of my house so the results would probably be slightly lower in an more open space but it does give you a rough estimate of the noise levels.

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My Exige is fitted with the 190 kit, CRP and the motorsport exhaust.Yesterday at a track day at Llandow it tested 100.5Db at a 1 metre distance 45 degrees, using 6000 revs.Have you ever tried to hold 6000 revs ??

3

Good point, the tests were done at a distance of 500mm as per race regs !!

4

I just went and tested my Elise with 200hp DVA setup, no cat and a slightly dead stainless SuperSports zorst4300 was 112db5600 was 120 although thats as high as my soundmeter goes. Those were taken @ 500mm @ 45deg.I’m quite glad I’m fitting a new zorst tommorow !!

5

Janspeed Sports (oval) and Eliseparts Silenced CRP - 98 dba at Prestwold, 96 dba at Curborough , 97.5 at Oulton Park. Just FYIAnd now 103 at Prestwold … I think teh Janspeed is falling apart - again[This message has been edited by AndyD (edited 02 May 2003).]

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Did a track day at Bedford Autodrome - fantastic day, I might add with 106 Loti present.For what it’s worth, my car registered 95db with a Janspeed exhaust (oval) @ 4600rpmKev.

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quote:Originally posted by Kp:…my car registered 95db with a Janspeed exhaust (oval) @ 4600rpmThat seems very low! Is the exhaust new? Do you have 190 with CRP?Ian [image]http://www.exiges.com/ubb/NonCGI/images/icons/smile.gif[/image]

8

Ian, Phil,after Cadwell, went to fine-tune the Powerspeed exhaust to Ashford and even though it sounds fairly quiet (you heard it) about a third of the packing material (glass fiber, hair like) had been blown away.The new exhaust tip design was fitted and the silencer repacked and (it may be my impression, but) the sound seems deeper and registered 93 db @ 5400 rpm.And the engine feels oohhh so smooth. Not bad!UldisPS - pics will follow (tomorrow or so, when I wash the car and take one)

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erm…this is exactly the problem I’m facing with the Geary one. Even after repacking it with supposed to be better material, on the way back to Switzerland, it has blown a lot of it out again. Phil suggested to wrap the tubing with some steel wool before putting the wadding in. might help you as well, Uldis. keep us informed and send some piccis because I’m still very interested in yours…later,Bruno

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Bruno,find below a couple of pics of the Powerspeed exhaust: [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image] Uldis [image]http://www.bookatrack.com/g2/uldis/5/640.155.100-0049_IMG.JPG[/image] [image]http://www.bookatrack.com/g2/uldis/5/640.161.100-0056_IMG.JPG[/image] [This message has been edited by Uldis (edited 12 May 2003).]

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cheers, Uldis… [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]...been in touch with Dave…they quoted 320 quid…with a choice of different end pipes…is that your final end pipe then? no signes of blowing out your wrapping again?later,Bruno

12

Yes, my final pipe (you can always ask a different tip).I don’t know why but the sound seems deeper at tickover to me while of course quieter (because of the new wrapping) on top.And cruising (throttle neutral, 2000-5000 rpm) barely sounds any louder than stock.No signs of the wrapping coming out (and now I have the perforated grille in there, should be able to see it when it does), but Dave mentioned that after 2000 miles of hard (and track) use, losing a third of the wrapping wasn’t so bad. I also mentioned the possibility of the steel wool wrapping around the holes so that the glass fiber (that’s what it is) can’t pass.He told me he experimented with the idea and showed me an opened exhaust with it. He said he (and the client) didn’t like it because it gave a strange metallic raspy tone to the sound.Who knows, next time I need to repack my silencer (hope not soon), I could try it. If I don’t like it I can always remove it.Anyway, so far it’s good. [image]http://www.exiges.com/ubb/NonCGI/images/icons/grin.gif[/image]Uldis

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cheers, Uldis, for the report…sounds goood…later,Bruno