bigpig
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| posted on 13/9/09 at 03:27 PM |
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Trying to get the noise down
Well on my fleabay meter I'm getting 104dba at 4000 rpm on my Pinto.
I've tried a restrictor in the pipes a sort of "><" with the sides filled in, but it makes no difference at all"
The problem I have is that the Robin Hood (GBS) exhausts have a 90 degree bend at the end so I can't get a noise killer in there. Anyone tried
one of these shoved down the pipe instead?
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Jon Ison
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| posted on 13/9/09 at 04:10 PM |
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Rather than a DB killer read "power killer" you need a decent silencer to do the job properly.
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bigpig
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| posted on 13/9/09 at 04:58 PM |
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Yep, but I'mnot going to buy another exhaust system though as that would leave me skint.
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Jon Ison
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| posted on 13/9/09 at 05:47 PM |
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Fair enough, but its only a silencer you need, not a system.
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whitestu
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| posted on 13/9/09 at 06:55 PM |
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I fitted an R1 can to mine - probably not the best flowing exhaust, but they are cheap and gave less than 89db on my Zetec.
Stu
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Antnicuk
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| posted on 13/9/09 at 06:56 PM |
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with my old silencer i measured my DB at 104, just by putting a new repackable LARGE silencer on it i lowered it to 96 on the same meter at 4500 but
Cadwell park noise tested me at 88 db at 4000 rpm.
I had know idea just the silencer would make so much diffference. Also, if your silencer is not knew, they blow out the stuffing so quickly, just
repacking it can make a huge difference.
600 BHP per ton, Stylus Brought back from the dead! Turbo Rotary Powered!
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ReMan
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| posted on 13/9/09 at 07:22 PM |
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If it's just for IVA I have a very quiet one I can lend
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bigpig
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| posted on 13/9/09 at 08:33 PM |
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Cheers Reman, sounds grovey. I'm going to do some measurments on the existing exhaust and see can be done. The existing pipe is not straight
going into the can unfortunatly. Its a pitty they didn't make the system in 3 sections.
It looks like (as the GBS unit has quite a lot of pipe on the can) it may need some modification to take any other can. Hpefully it can be done with a
bit of welding & cutting.
One thing a decent noise killed should add is more midrange, top end power is reduced, but the pressure waves increase in the mid range (based on
what changing a bit road can to a race can does).
The GBS system is a bit of a PITA as I've found, given its a straight through. Hoping to save a hundred odd quide over the MK one has turned out
to be false economy in the end. Its one of those which is an end can, but has a good amount of pipe on it as well as the hanger welded on.
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bigpig
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| posted on 13/9/09 at 08:37 PM |
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quote:
Originally posted by Jon Ison
Fair enough, but its only a silencer you need, not a system.
Thanks, yep. Unfortuntantly the GBS system is 2 parts, downpipes to collector, then exit pipe to exhaust.
Its the EX01 part on the kit parts direct site
http://www.kitpartsdirect.com/page6.htm
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ReMan
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| posted on 13/9/09 at 09:15 PM |
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"One thing a decent noise killed should add is more midrange, top end power is reduced, but the pressure waves increase in the mid range (based
on what changing a bit road can to a race can does). "
In theory maybe, but in practice it can also kill the power dead!
The "very quiet" can I have kills the power on the 'blade by about 25% accross the range and stopps it reving out fully
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MikeRJ
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| posted on 14/9/09 at 04:55 AM |
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quote:
Originally posted by bigpig
One thing a decent noise killed should add is more midrange, top end power is reduced, but the pressure waves increase in the mid range (based on
what changing a bit road can to a race can does).
Reduction in power from fitting a freer flowing exhaust is generally down to it messing the mixture up, e.g. fitting an LCB manifold and straight
through exhaust to a mini will kill the performance and make it horrible to drive unless you get a suitable needle for the carb.
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