ESE's works engine tuner

[SwePatrick]

An idea I've been playing with for a while now:

As I'm not restricted by any rules or regulations, how about a supercharged "hyprid" two stroke?
Blower connected directly to the transferports, a relatively small exhaust port, a pipe designed to retain as much energy as possible before the convergent cone(a pure "port blocker"), and an electric motor for bringing it into the powerband.

The point being to blow huge amounts of fresh mix through the cylinder, eliminating any possibility for mixing with spent gases, and at the same time (due to the small exhaust port/blocking pipe) build considerable pressure before exhaust port closing.

Stupid?

Like an old diesel twostroke

https://www.youtube.com/watch?v=xTQvM1cXOyc
https://www.youtube.com/watch?v=mA7l3dpx6t0

[TZ350]

As I'm not restricted by any rules or regulations, how about a supercharged "hyprid" two stroke? Blower connected directly to the transfer ports, a relatively small exhaust port, a pipe designed to retain as much energy as possible before the convergent cone(a pure "port blocker"), and an electric motor for bringing it into the powerband. Stupid?

Nothing stupid about that, or maybe everything but if the engine capacity was right and started life as a non competition motorcycle engine then it would be totally go for Buckets. I like your thinking.

[husaberg]

Nothing stupid about that, or maybe everything but if the engine capacity was right and started life as a non competition motorcycle engine then it would be totally go for Buckets. I like your thinking.

There is a company in the states that make very small supoerchargers suitable for 50CC.
https://www.oguraclutch.co.jp/e/prod...rger/type.html
https://www.oguraclutch.co.jp/e/prod...rger/size.html
The nanufacturer is known for its high end racing clutches so it should be very well made and likely priced accordingly.

[adegnes]

Like an old diesel twostroke

https://www.youtube.com/watch?v=xTQvM1cXOyc
https://www.youtube.com/watch?v=mA7l3dpx6t0

Yep! BTW, did you find any more info on that small supercharged two stroke you posted a while back?

Nothing stupid about that, or maybe everything but if the engine capacity was right and started life as a non competition motorcycle engine then it would be totally go for Buckets. I like your thinking.

Thanks!

There is a company in the states that make very small supoerchargers suitable for 50CC.
https://www.oguraclutch.co.jp/e/prod...rger/type.html
https://www.oguraclutch.co.jp/e/prod...rger/size.html
The nanufacturer is known for its high end racing clutches so it should be very well made and likely priced accordingly.

Nice!
I'll contact them, maybe I can persuade them into sending me a unit for testing purposes...

I'll make a video further explaining what I have in mind.

[41juergen]

I understand. sometimes you just do the best you can and leave the rest to compromise. to get down to 75% i ended up needing to do a lot of welding on the floor and roof of the main passage. was pain in the ass . the cylinder was designed sometime in the early 80's and really there was nothing good about its design. sometimes i wonder if it was just a big waste of time. hopefully your adventure is less grief than mine

Yep, know what you mean. Attached a first try for the next set of cylinders...

[peewee]

RZ slipping clutch; I've never looked at this sort of thing as assumed a drag thing, but Wob was posting of issues and the night before my RZ started slipping on the dyno at anything approaching 90hp (its a CPI 496cc).

So what is having a lockup clutch like? It applies pressure, but does it change the action so it feels weird?

Wonder if it needs a spacer.

http://m.ebay.com/itm/NEW-Yamaha-Ban...257Ciid%253A11

like Patrick said it may be difficult or impossible to use the clutch at high revs ( youll be trying to push the pressure plate open while the fingers are trying to keep it clamped shut). the whole assembly bolts on top of the pressure plate. no spacer needed. but it makes the engine wider so you need a special clutch cover. its mostly for drag racing as you never use the clutch but on take off http://www.ebay.com/itm/BANSHEE-CLUT...3D141972896541

I think they have one that fits under standard clutch cover. uses ballbearings in ramped grooves. not sure how well the clutch would work on this as its function is the same as the finger style. says its good for 140+HP http://www.ebay.com/itm/New-Yamaha-Y...3D151968425953

what about stiffer springs and hydraulic setup ?

[SwePatrick]

Yep! BTW, did you find any more info on that small supercharged two stroke you posted a while back?

No nothing.
I googled for a couple of hours, nothing

[husaberg]

No nothing.
I googled for a couple of hours, nothing

Challange accepted
Post a link or the picture.

[TZ350]

""Well its been awhile!!, but the bike hit the dyno!!, and it turns out I have alot of tuning to do.........running pig rich in boost it seems. Its funnny because on the street it always seemed pretty good into and above 20psi. Anyways at 10.5 psi boost the bike is making a solid 70hp at the wheel at 10200rpm, anything over 11psi and afr's go to around 8:1. hopefully in the next few weeks I can work on the tune and get the afrs perfect into the 25psi range. It takes alot of load to spool the turbo, the pulls were done in 6th gear. I have a gt12 I might try and see if I can get a bit faster spool. I expect to be well over 100hp soon""

.... http://supermotojunkie.com/showthrea...f-cafe-chassis!!!

Turbo RZ project.

[41juergen]

""Well its been awhile!!, but the bike hit the dyno!!, and it turns out I have alot of tuning to do.........running pig rich in boost it seems. Its funnny because on the street it always seemed pretty good into and above 20psi. Anyways at 10.5 psi boost the bike is making a solid 70hp at the wheel at 10200rpm, anything over 11psi and afr's go to around 8:1. hopefully in the next few weeks I can work on the tune and get the afrs perfect into the 25psi range. It takes alot of load to spool the turbo, the pulls were done in 6th gear. I have a gt12 I might try and see if I can get a bit faster spool. I expect to be well over 100hp soon""

.... http://supermotojunkie.com/showthrea...f-cafe-chassis!!!

Turbo RZ project.

Interesting project, as the English man would say. Wob gets the 70HP out of 1 cylinder.....

[Frits Overmars]

Just curious what happened to all of ktms 125gp bikes? Can not say I recall seeing any at club level. were they only a factory effort?

The ones with the injector were works bikes, but the 125 cc KTM production racers were used in the Red Bull Rookies Cup for years, so there must be dozens around.
I too wonder where they all went.

[sispeed]

The ones with the injector were works bikes, but the 125 cc KTM production racers were used in the Red Bull Rookie Cup for years, so there must be dozens around.
I too wonder where they all went.

I know a person in Austria who ownes one.
https://www.facebook.com/christopher.eder.7?fref=ts
Hope you can see this without an account

[wobbly]

I have some 30 % uprated springs to use in Yamaha/Hinson RZ/Banshee clutches,just use 3 of them and the lever isnt too stiff.
PM me if you want some,they are good for the 130RWHp I got in Makrs Landspeed RD400.
The lockup clutch is no good for a 2T in roadracing,where many riders use the clutch on downshifting to keep the back stable under brakes.
And yes you must use a speedshifter on the upshift.

Just a small point re the 75% cylinder exit area rule of thumb,this area is just a by product of the desire to reduce the volume of the whole exit duct.
The other guide is that this area is most effective if it occurs at around 1.5x the bore diameter,thus many cylinders are way too short.
I have added extra ,smaller area ,duct length to many cylinders, by extending the bolt on spigot plate, or making a female spigot on the cylinder into a male one.
Then the header that sits after the oval to round transition, starts at 2x bore.

[F5 Dave]

Thanks. I have uprated springs and new oem FZR plates. I'll go have a fish around might have only fit 3 could try all 6. Lever arm is lengthened, Ido have a cheapo hhydraulic cable conversion Iwas ggoing to try out.

[speedpro]

Depending on how many plates you have, what about thinning all the steels a small amount and taking small amounts off the alloy clamping faces. If you can fit an extra pair of plates that is a useful increase in clutch surface area.