Supercharged 2-Stroke

[SuperN8]

I ran across a couple of photos and found them to be a little Intriguing to say the least, besides the coolness factor to these superchargers has anyone ever used one or rode a ski with one. Besides the size of them I think they are limited to hulls that will fit it but I think this would be a good way to gain some HP? No? Also where can I buy one, cause they are awesome lol

 

[kswiatk]

It was on ebay a while ago. It does not work well at all.

 

[Big Kahuna]

Never worked well. Holeshot Engineering and Chris Fischetti tried to use them in the mid/late 80's.

 

[SuperN8]

sad it didn't work so well because it certain looks radical.
I wonder with newer technology and better designed rotors in superchargers and possibly better tuning that this could work today. or maybe 2-stroke watercraft just not good candidates for boosted applications.

 

[Big Kahuna]

They work great in 4 strokes. I think it was just to much for the 2 stroke 650's

 

[Quinc]

Never worked well. Holeshot Engineering and Chris Fischetti tried to use them in the mid/late 80's.

This @holeshot?

 

[Big Kahuna]

Dont think there is any connection. but who knows.

 

[yamanube]

Speedwerx is now building supercharger kits for two stroke sleds with great results.

 

[Big Kahuna]

looks like that is more in line with the motor size.

 

[speedysprocket]

I would venture to say those appear to be direct injected engines... With a carb, you're forcing a good portion of your air/fuel mixture straight out the exhaust before combustion.. At least with the DI, you can wait until the exhaust port is already closed bwfore injecting so that you conserve some fuel.

 

[yamanube]

I would venture to say those appear to be direct injected engines... With a carb, you're forcing a good portion of your air/fuel mixture straight out the exhaust before combustion.. At least with the DI, you can wait until the exhaust port is already closed bwfore injecting so that you conserve some fuel.

Possible, I am not a sled guy. I believe the one on the right is EFI but might not be DI, the one on the left, I have no idea.

 

[speedysprocket]

I made that assumption by looking at the spark plugs being offset and angled and all the other plugs and wires on the heads. Looks similar to the SeaDoo 951 DI I have... And it would make sense to do that.

 

[Quinc]

There is a couple threads on pwctoday from someone who owned it. Looks like he never figured it out and sold it.

 

[Quinc]

Looks like one for sale here too:
http://www.pwctoday.com/showthread.php?t=436984

@TheBuzzard knows everything pwc related. Maybe he can shed some light.

 

[Big Kahuna]

If I had to make a shot at the dark guess. If it did actually work. And it did process the fuel mixture. I would guess the weak link is the pump. May have made too much power and you just bored holes in the water spinning the prop.

 

[SuperN8]

Clearly this has been covered before, my mistake for kicking it up again
http://www.x-h2o.com/index.php?threads/supercharged-or-turbo-two-stroke.84566/page-3

@waxhead ski?

just curious, running a supercharger would you still have to use a expansion chambered pipe, since there will always be positive crankcase pressure to blow spent gases out of cylinders?

 

[yamanube]

Maybe it's the type of supercharger that makes the difference, some light reading makes it seem like the centrifugal supercharger would be a better match for a two stroke than the roots type used in the 90s. From what I have read, the roots blowers have much higher initial/low rpm boost which might make it tougher to keep the intake charge in the cylinder down low?

These things would probably destroy reeds at an alarming rate.

 

[holeshot]

Different Holeshot not me.

I think supercharging has potential in the right hands. i would think a centrifigal blow through with an intercooler and fuel injection on e85 would be a correct approach these days.

 

[yamanube]

Clearly this has been covered before, my mistake for kicking it up again
http://www.x-h2o.com/index.php?threads/supercharged-or-turbo-two-stroke.84566/page-3

@waxhead ski?



just curious, running a supercharger would you still have to use a expansion chambered pipe, since there will always be positive crankcase pressure to blow spent gases out of cylinders?

Even more so, the tuned pipe works to push the intake charge back into the cylinder with sound waves, the supercharger is trying to do exactly the opposite at all times. I think this is why the turbo can work better, it provides extra back pressure on the exhaust side to help negate this, which would likely also negate the benefit of a tuned chamber (I would think).

 

[TheBuzzard]

@TheBuzzard[/USER] knows everything pwc related. Maybe he can shed some light.

apparently you have mistaken me for somebody that gives a S*#@!
F that thing and the whole useless novelty project, but by all means,carry on.