• 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 The previous version was outdated and no longer supported.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!

250-500cc 2 Stroke back pressure

Less back pressure tends to improve low end response, more improves top end. And that's a pretty generic explanation.
 
"Back pressure" is sort of an outdated/vague term. 2-strokes (and 4 strokes, although in different ways) depend on waves bouncing and resonating inside the chamber, so the static pressure in an exhaust is not the complete picture.

There are lots of "urban legends" about "backpressure" with regard to 4-stroke performance (more backpressure means more low-end torque, etc), but the reality is that it's not really backpressure that is having an effect, it's wave scavenging. Static backpressure is almost always a bad thing...
 
I agree, but my reference is totally based on 2 stroke and "stinger" size. But, as you stated, it's really it's effect in scavenging. The term "backpressure" is very generic, loosely used term from way back in time. When that phrase was coined, people didn't really understand what was going on and simplified it to the term "backpressure".

I thought I understood what he meant by his general question, hence the "generic explanation" disclaimer on the end.
 
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