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Author: Subject: Exhaust decibels
maccmike

posted on 10/9/12 at 04:43 PM Reply With Quote
Exhaust decibels

I acquired a db meter.

Readings are as follows at 4k rpm (of 10.5k);

no db killer - 104.2

db killer #1 - 100.7

db killer #2 - 100.3

I rev'd it to around 8k and it read 108+

Suggestions on how I can reduce it further in the locost manner please

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RickRick

posted on 10/9/12 at 05:17 PM Reply With Quote
Apparently just putting a bolt in the tail pipe can help small hole in the end of the pipe, install, run nut up it, so that the threaded part just points across the diameter hoep that makes sense, another option is a ball of wire wool down the pipe before db killers installed, no idea how long this lasts though
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mark chandler

posted on 10/9/12 at 06:55 PM Reply With Quote
look at intake noise, not exhaust as this can be just as loud !
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maccmike

posted on 10/9/12 at 08:20 PM Reply With Quote
Thanks for that, its the original airbox with an aftermarket 4-1 exhaust so Iv no doubt its the latter.
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Chippy

posted on 10/9/12 at 09:59 PM Reply With Quote
The simple answer is to fit a bigger and better silencer, 6" can with perforated pipe and Acustafil wadding, worked on my V6 reduced the noise a fair amount. HTH Ray





To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy

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maccmike

posted on 10/9/12 at 10:25 PM Reply With Quote
Yeah I can of figured that'd be the proper solution. I dont like spending money though Ray haha.
Got couple of things to try tomorrow then Il go from there

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Chippy

posted on 10/9/12 at 10:31 PM Reply With Quote
One thing about the bigger silencer, over the DB killer, you wont loose all those lovely BHP, and don't be such a tight wad, as somebody on here has on there page, (anything with tits or wheels is going to cost you money). Cheers Ray





To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy

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maccmike

posted on 10/9/12 at 11:32 PM Reply With Quote
hahahaha
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ashg

posted on 10/9/12 at 11:53 PM Reply With Quote
quote:
Originally posted by RickRick
another option is a ball of wire wool down the pipe before db killers installed, no idea how long this lasts though


tried that. makes the car cut out half way to the iva on the motorway. it wasn't fun taking the can off at the side of the road in the january snow getting the wool out and getting to the test on time.





Anything With Tits or Wheels Will cost you MONEY!!

Haynes Roadster (Finished)
Exocet (Finished & Sold)
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bi22le

posted on 11/9/12 at 06:20 AM Reply With Quote
Acustafil is cheap. If you have a repackable exhaust then just try it, if not then consider making it repackable!!

What exhaust can have you got at the mo? Is it bolt on and exchangable, if so buy a standard bike can from ebay and try that. Or you could add a bend on the end of the pipe.

Essentially anything you do will choke some power.





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maccmike

posted on 11/9/12 at 08:41 AM Reply With Quote
hi bi22le,
yeah its a bolt on, outlet is 45 degree already.
Im going to whip it off and look inside.
i have a feeling there will be no baffle.
it sounds great, but i want the type of sound you get out the factory and dont mind losing some power.

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Minicooper

posted on 11/9/12 at 09:35 AM Reply With Quote
What about a standard large capacity single rear box like the one fitted to the ZX12r's for example they are very quiet compared to most exhausts and there are plenty available on the bay

Cheers
David

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maccmike

posted on 11/9/12 at 11:12 AM Reply With Quote
hi mini, just tried a road legal can that isnt a straight through like mine, it was only as quiet as mine but with a db killer in, put the killer in the new can but still above 100db. and much heavier, going to repack mine this afternoon, mod the db killer and see from there.
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Minicooper

posted on 11/9/12 at 12:38 PM Reply With Quote
That's strange as on the road a standard pipe like the ZX12r is whisper quiet compared to the screaming sports bike you get, oh well worth a shot

Mike have you a build thread for your three wheeler? I'm interested longer term making a three wheeler perhaps front wheel drive if I can get it to look right, the stance, wheelbase to track ratio on your car looks spot on, would you have those details to hand, it would be interesting to know them as a starting point.

Did your car have a GSXR1100 engine in it at some point, I remember something similiar for sale years ago?

Cheers
David

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maccmike

posted on 11/9/12 at 12:55 PM Reply With Quote
Hi mate, when I bought it, it had an old z1000 engine, I dropped a valve and it wasnt very powreful anyway so dropped the zzr in it last year.
I dont have a diary but could take measurements for you.
Side profile looks good but front on its fugly.
Your welcome to visit if your ever passing.

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Minicooper

posted on 11/9/12 at 01:17 PM Reply With Quote
Thanks Mike,
The wheelbase in particular would be interesting to know

I assume it goes very well with the ZZR1100 motor, I want the performance but with a standard, cheap, available motor, like a ZX9, or early R1, in order to do that you need to be as light as possible

Cheers
David

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maccmike

posted on 11/9/12 at 02:10 PM Reply With Quote
its pissing down now but will measure base and track and let you know.
to say its ballistic is an understatement.
its hard getting the power down with only one contact patch and wheel spin too easy, even at motorway speed.
thats why im not too fussed about losing bhp with the exhaust.
repacked the silencer and modded the db killer, at idle its 10db quieter, at 4k its just over 100 so that'll do.

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Minicooper

posted on 11/9/12 at 06:28 PM Reply With Quote
Thanks Mike,
When it suits yourself, I won't be doing anything other than thinking and drawing at this stage

Cheers
David

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