Noise.


and mirrors

Noise 101.7dB pass now 99dB

mirrors need to raise about 1" so can see over rear arches

Thats basically it except I have to get proof of supressed leads,which they are but not marked.

I could have sorted the mirrors and lead issue out at the test station but could not get the noise down anyway. I have repacked the exhaust and fitted internal bolt in baffles but no joy. I have 2 exhausts each with silencers and Cats. Trying to think of a solution.

Perhaps a transverse box with 2 inlets and 2 outlets. any suggetions welcome



[Edited on 12/5/10 by Lightning]
Rescued attachment rear exhausts.jpg

unlucky steve, ive been watching your build for a while.

its a very good fail if there is such a thing. maybe just fit the stock airbox for the test? not sure what your space issues are with space underneath.


ant

did you do the noise with the rear cowl off?
cos you would have got a hell of a lot of induction noice with that sausage filter if u did

sorry to hear about your fail. but in the scheme of things its not too bad.

little bit of work on the exhausts

Then move the mirror and your on the road.

That's a great result.

Answers to the above.

The air box wont fit

The rear body section was on and I put in sound deadening inside and covered the rear facing vents too.

Any one know of exhaust specialists down this neck of the woods
(Devon). Been to Apex this afternoon in Collumpton but they cant look at it for at least 6 weeks

how did he measure the sound
1 a measure of each pipe
2 a measure in the middle
3 a measure from just one side

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Originally posted by Lightning
I have 2 exhausts each with silencers and Cats. Trying to think of a solution.



[Edited on 12/5/10 by Lightning]

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4 into 1 back to 2 as in a motorcycle.

He measured each pipe to the side. Not in the middle. Both were within about .2dB of each other

are they the stock exhaust cans from the bike?

No Mk cans and recently repacked

That's a 'good' fail, Steve. Well done.
I have an R1 can which I used for SVA and, considering they are deemed to be a quiet silencer, I only just got under noise limit (from memory, I think it was measured at 100.5dB) So I can only conclude that my sausage filter contributed significantly to the overall noise level
I'd say you need to look at reducing induction noise rather than the exhaust's.
Can't you manufacture a bespoke airbox to fit under the cowling? (after all, you did for your Avon IIRC)

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I have repacked the exhaust and fitted internal bolt in baffles but no joy. I have 2 exhausts each with silencers and Cats. Trying to think of a solution.

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Can't you manufacture a bespoke airbox to fit under the cowling? (after all, you did for your Avon IIRC)

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I'd fit a couple of s/h bike cans for the test if you can. Something from a basic tourer/commuter type bike e.g. Suzuki bandit would be cheap and effective.

put 90 degree bends on the ends of the exhuast, facing away from each other ?

What the others have said... As good fail as you can get. Hope you get the noise sorted quickly and you'll be on the road in no time. Good luck!

Steve,
What dia. is the inlet to your silencers?
If 2" you're welcome to borrow my modified R1 can to see if its significantly quieter than your mk ones.
May help you decide if you should shell out on new silencers
(be an excuse to pop up to have a butchers at the car)

|Bandit can/s will make it very quiet they are fairly cheap too

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Originally posted by dave r
put 90 degree bends on the ends of the exhuast, facing away from each other ?

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I got my noise down from 105 to 98.6 (pass!) with a bit of DIY.
- suitably sized Jetex dB insert well lagged with wire wool fitted near the tail-pipe.
- DIY baffle, consisting of a large penny/repair washer bolted to a bracket inserted in the middle of the perforated pipe, still leaving about 10mm round the sides. Thinking was that it blocked the direct gas and noise path, forcing the flow through the wadding.

I'm sure the above would strangle the engine at full chat, but for pottering down to VOSA, and for running on little or no load it's fine.

Mine's a 2l Honda S2000 engine - noise test at 6000 rpm. 2 1/2 inch system - 6 inch can with an integral cat in the front.

Hi, I'm between Tavistock and Plymouth and I have a pair of YZF1000R Thunderace silencers that you are welcome to borrow and try to see if they are any quieter! I also have welding equipment should some adaptation be required!

I also don't mind looking at re-packing the cans if necessary!

[Edited on 13/5/10 by Strontium Dog]

2 cats + 2 silencers on 1 bike engine , I think I would go with the induction noise theory, what I would personally do is buy a £25 noise meter and take a reading as is (it doesn't have to be accurate,you are only checking the difference) fit a standard airbox and check again, this will tell you whether the problem is exhaust or induction and could save time and money in the long run

Strontium Dog U2U

40inches

I think thats a most excellent idea. at least then i would have a clue as to whether it was quieter or not and not waste £90 each retest.
Now what meter to buy????

[Edited on 14/5/10 by Lightning]

Having known that car in its previous incarnation attending Hillclimbs I was marshalling at, it now looks superb! I'm sure you'll sort the noise issues and be on the road soon. JC

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Originally posted by Lightning
40inches

I think thats a most excellent idea. at least then i would have a clue as to whether it was quieter or not and not waste £90 each retest.
Now what meter to buy????

[Edited on 14/5/10 by Lightning]

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Steve,
if you were to borrow 'Strontium Dog's' silencers, I'd be happy to pick them up for you if it makes it easier for you to get them from mine? (be an excuse for a run out this weekend if weather's ok)

Andy , I have a arranged to pick them up on Sunday. Trip across the moors is always good. Thanks anyway. I need to also find sime mirrors to borrow from someone or get some cheep motorcycle ones that are a bit further out. I want ot keep the mirrors I have. Whats behind me is of no interest.

quote:

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Originally posted by Lightning
Andy , I have a arranged to pick them up on Sunday. Trip across the moors is always good. Thanks anyway. I need to also find sime mirrors to borrow from someone or get some cheep motorcycle ones that are a bit further out. I want ot keep the mirrors I have. Whats behind me is of no interest.

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I hoped you might have someting. How long are the stems? can you give me a call. i u2u'ed my number. cheers

quote:

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Originally posted by Lightning
I hoped you might have someting. How long are the stems? can you give me a call. i u2u'ed my number. cheers

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