Jump to content
Sign in to follow this  

need a stealthy pig

Recommended Posts

here's the scoop- i have an '04 XRR- it's uncorked but otherwise stock. it's undergoing a S-L-O-W conversion to an SM setup. i'm going to ship the motor off and have her punched out to a 680 torque monster- the engine is going to be built from the bottom up with durability in mind, not just to be fast. i don't know shit about engine building

my question- i WANT to have this thing run as quiet as possible- close to off the showroom quiet. where/when i ride dictates having a very quiet bike- otherwise my riding time will be greatly reduced. the best i heard so far is an FMF PowerCore pipe/header setup. i had that setup on my XR650L, and while it was not obnoxious, it was still substantial.

i've heard elsewhere that a big fat stock pipe off a streetbike can be fitted and the bike will be whisper quiet but not choke the engine down- i asked here at TT and other places with no reply. i understand that a quiet pipe might not be as powerful as an open race system, but i'm hoping there can be an acceptable compromise. i've even seen a 'second' silencer added to the existing one. anyone have any thoughts/ideas/insight?

one other thing- why is it KTM EXC's, CRF450X's, WR450's, etc come with quiet pipes and even stock they haul ass- in some cases a perf pipe fitted only gives a marginal increase in power which tells me the stock pipe is pretty darn good.

please don't flame me for this, i just want to ride hard late at night and ride trails with no hassles from neighbors/LE:ride:

thnx in advance:thumbsup:

Share this post


Link to post
Share on other sites

I've seen people add a 90 degree elbow to the end of the silencer that points straight down. It seems that it would reduce the distance the sound travels.

I think your best bet would be to add an additional silencer - possibly make it removable. I highly doubt you would be able to detect a difference in power as long as the flow was not restrictive.

It will be interesting to see what you come up with.

Share this post


Link to post
Share on other sites

akarob- thnx for the reply! i think that will be my best bet- just add a second removable silencer. i've seen a setup like that before, the downside is if you're offroading, it could get ripped off in a spill. with that said, i mostly want this setup for the street, so that could be a solution.

does anyone have any idea IF a large silencer off a streetbike would work? as i said i don'r know jack about the dynamics of an exhaust system (backpressure etc...) i seen/read somewhere where a guy put a '02/'03 Yamaha R1 on his BRP and said it worked great, but who knows what that means???

Share this post


Link to post
Share on other sites

The key to quieting a thumper is muffler volume, so a large stock slip-on from a street bike is a good bet to work well.

Dave

Share this post


Link to post
Share on other sites

I have to say that 650R mufflers look remarkably like CRF 250/450X mufflers. I use either on all my 600's and they are very quiet. The 250X is quieter than a stock XL600 Muffler and believe me thats saying something. Even the 450X is quieter than a standard XR600 Muffler and almost on a par with the 250X on the XL600..Not quite sure why the 650R Muffler would be any louder than either of them..

http://www.trademe.co.nz/Trade-Me-Motors/Motorbikes/Parts-for-sale/Exhaust/auction-275822422.htm

Thats a 250X Muffler..Still for sale and still cheap.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×