BEC "7" Style exhuast can help

[kriss]

Hi guys,

Had my first track session a few weeks back in the R1 Indy and with my CF Micron bike exhuast I hit 107 db. With a bit of tinkering at "7 Indulgence" down the road at Brands, they fitted a bung which managed to get the db down to 104 db, with a very favourable noise tester when returning to the track lol.

SO, I need a bigger exhuast can to cut down my db! My mates westfield has an 07 busa lump and pipercross style filter and is around 98-99 db!

My R1 is std airbox and micron and hits 104 at best!!!

Who can supply me a decent DB killer exhuast to fit to my 4-1 manifold, preferably off the shelf>?

[Furyblade_Lee]

Try RAW engineering who make the Striker. 107 is crazy. Mine (inj R1) is around 99 or 100db, even when the Lambda plag came out at Zolder I was black flagged at only 103.5! What you might find is you are getting a lot of induction noise, certainly can contribute a lot of db's. Try ducting the air intake to the front grill area, will give cold air as a bonus as well as quieting down intake noise. And keep any ducts / holes / vents in the bonnet to a minimum, these let a lot of noise out too. Another trick is to make sure the exhaust tailpipe blowes downwards more than outwards, the last thing you want is it aiming directly at the drive-by noise meters. But it will always be difficult to get a BEC under 100dbs comfortably, if you can get a genuine 98 then i'd be well happy.

[Hobzy]

Kriss do a search on locostbuilders - there was a thread a few weeks ago about exactly this. Mines an 03 R1 and it is flippin loud. I did buy a couple of R1 cans off the bay to try a twin setup but never got round to it...

Heres my thread...http://www.locostbuilders.co.uk/viewthread.php?tid=94550

[Hobzy]

Merlin also do tips to chuck on the end that will egt it down about 4dB...

[Comadis]

if you use a standard side-exhaust it will be very hard to cut down the noise.

in the meanwhile you can see certain kit-manufacturers who route the exhaust from the side over the rear axle towards the back.

this means you have a longer route where you can fit a 2nd silencer.

another possibility is to use 1 single repackable side silencer with a big diameter (e.g. 6 inch) and as long as possible (the longer the more absorbing distance you have).

i got mine from Wunoff Exhaust Solutions

Address: Block C
Friars Work
Bradford Road
Idle
Bradford
West Yorkshire
BD10 8SX

Telephone: [phone]


but this will not be the final solution:

i also used a db-killer between manifold and silencer, and (the most important thing)a PIPERCROSS airfilter box e.g.: C6200LH to cut down my noise level on my x-flow powered kitcar with twin side weber carbs for the local mot.

the problem is that the db-killer will also reduce the flow in the exhaust system, which means you have less power.

but i think for uk-laws a db-killer wont be necessary.

most important thing is that you reduce the intake AND the exhaust noise.

most people forget the intake!!!

Edited by Comadis on Monday 20th October 18:39

[robcollingridge]

I've had no end of problems with my Fury R1 and noise. I hit 108dB @ 7000rpm on my last track day. That's with a free flow race exhaust, I'd just repacked. The basalt had compressed though. Even when repacked, it is still quite loud.

I've also got a standard 2003 R1 can with catalyst and this is way quieter and passed a noise test. Induction noise is my main problem now and I'm fabricating a GRP airbox to lower induction noise.

Lots of details: http://www.robcollingridge.com/kitcar/drive/2008/0...

Rob