• 2 Stroke Husqvarna Motorcycles Made In Italy - About 1989 to 2014
     WR = 2st Enduro & CR = 2st Cross

  • Hi everyone,

    As you all know, Coffee (Dean) passed away a couple of years ago. I am Dean's ex-wife's husband and happen to have spent my career in tech. Over the years, I occasionally helped Dean with various tech issues.

    When he passed, I worked with his kids to gather the necessary credentials to keep this site running. Since then (and for however long they worked with Coffee), Woodschick and Dirtdame have been maintaining the site and covering the costs. Without their hard work and financial support, CafeHusky would have been lost.

    Over the past couple of weeks, I’ve been working to migrate the site to a free cloud compute instance so that Woodschick and Dirtdame no longer have to fund it. At the same time, I’ve updated the site to a current version of XenForo (the discussion software it runs on). The previous version was outdated and no longer supported.

    Unfortunately, the new software version doesn’t support importing the old site’s styles, so for now, you’ll see the XenForo default style. This may change over time.

    Coffee didn’t document the work he did on the site, so I’ve been digging through the old setup to understand how everything was running. There may still be things I’ve missed. One known issue is that email functionality is not yet working on the new site, but I hope to resolve this over time.

    Thanks for your patience and support!

All 2st Pipe/Expansion Chamber Shape

M

mikebru

Husqvarna
AA Class
What is it about the shape of a 2 stroke pipe that makes it a top or bottom end power pipe?

How does the shape influence the power? Influence jetting?

I have a DEP pipe on my WR250 that seems good to me. I also have a slightly dented Gnarly I'm thinking about trying for the heck of it. I'm not a racer, just a woods rider. However, I don't want to mess up a good thing and have to fool around with jetting. I heard the Gnarly is a "bottom end pipe".

Thanks
Mike
 
Good article, Ohmygewd.

I guess I have a more basic question: Can somebody look at a pipe, without knowing the pipe's characteristics, and say it is a bottom end or top end pipe?

Thanks
Mike
 
mikebru said:
Good article, Ohmygewd.

I guess I have a more basic question: Can somebody look at a pipe, without knowing the pipe's characteristics, and say it is a bottom end or top end pipe?

Thanks
Mike
Click to expand...


Hey Mike, you can by looking how the pipe tapers from both end of the cone, the length of the header section and the size of the cone, gradual tapering, longer header and smaller cone generally say's l'm more a torque pipe whilst the opposite are more HP with over rev.
Great visual example is compare the FMF Gnarly vs Fatty and then SST...then again, if correctly adjusting the port timings to one of these pipe's, you can 'tune' bike to the exhaust, then we get into the area of porting/timing and ignition= $$$

What are you after?
 
A mirical by the sound of, lol
Yes you can as omg has said you can also buy books and read about all the equasions and designs of pipes / porting two strokes.
Most say they are a simple engine design but f me sideways there is alot more too it the most give credit.
Also if your after top end you can start messing with compression ratios and port timing knife edging transfer ports and flowing corners slightly more... Or you can just ride and live without that ever coming up again.
 
Wholeheartedly agree Juicy, this is where the term black art of 2 strokes was coined...if you've got plenty of coin and can find one of these tuners, then you can have a barrels/heads and pipes custom made to whatever application your after.
4t engine tuning is far easier then 2t's in terms of extracting that 5%-1% of power.
 
You must log in or register to reply here.
Back
Top