ESE's works engine tuner

[richban]

I saw a 1.5 hp gain swapping from a 30 to 32 on my bike with no drop in the mid range.

[TZ350]

yeah i was meaning is you have spent a lot of time with your engine tuning with the 24mm choke carb.
so it doesn't hugely surprise me that you didn't obtain instant results with a larger choke carb.

Yes ... it was just a quick test to get some idea if the 24 was choking it.

Its still hugely impressive i can remember someone saying no air cooled 125 will obtain more than 24HP with a 24 mm carb lol

And yes ... that is the problem with reliying on ones own real life experance and all that, because by definition its limited, I think researching everything you can and a bit of intelligence expands whats possible beyond what has already been done. Happy to be proved wrong of course.

[bucketracer]

the real irony is when the individual slams doing wide ranging research then spends so much time on the net pushing their own opinions....... i am eternally grateful Frits and Jan, Wob etc spent their time more constructively giving away there hard gained knowledge so freely ..........

Watching SS90's recent exchange with Wax, which seems to have exposed some gaps in SS90's industry knowledge and that leaves me thinking that poor old SS's real life experience and all of that has let him down a little bit.

[husaberg]

Teasing apart, it is my considered opinion that shiftboxes would have disappeared decades ago if the FIM hadn't blocked their development.

I have several knowledgeable people make similar arguments Frits, but I have never seen this in action

I wonder myself how much more knowledgeable than Frits opinion he really needs.............
How can Frits somehow lacking in "industry experience"
i also assume he has sought out some pretty clued up individuals for the CVT on the FOS concept engine. AS well as drawing own his own experience

Watching SS90's recent exchange with Wax, which seems to have exposed some gaps in SS90's industry knowledge and leaves me thinking that pore old SS's real life experience and all of that has let him down a little bit.

And yes ... that is the problem with reliying on ones own real life experance and all that, because by definition its limited, I think researching everything you can and a bit of intelligence expands whats possible beyond what has already been done. Happy to be proved wrong of course.

the real irony is when the individual slams doing wide ranging research then spends so much time on the net pushing their own opinions.......
i am eternally grateful Frits and Jan, Wob etc spent their time more constructively giving away there hard gained knowledge so freely and so much time answering questions. yet are always so modest and nonjudgmental of others..........esp in-spite of their success.... Make you wonder really...........

The inlet from the manifold rubber to the rotary valve port and the port itself are optimized for 31mm. Both the 24 and 30 carb taper out to 31mm on the engine side.

The 24 has of course had a lot of dyno time. For the test the ignition and everything else was left the same as the 24 but the 30 ran reasonably Ok with the 24's jetting and was given sufficient runs to find the main jet that gave best power.

Interestingly the 30 required a much smaller main jet than the 24.

yeah i was meaning is you have spent a lot of time with your engine tuning with the 24mm choke carb.
so it doesn't hugely surprise me that you didn't obtain instant results with a larger choke carb.
i would have thought it may have obtained a little more past peak power but then again i guess it was again optimized for its rev potential anyway as it was. Its still hugely impressive i can remember someone saying no air cooled 125 will obtain more than 24HP with a 24 mm carb
lol

[Buckets4Me]

[husaberg]

ouch............

[speedpro]

It's been bugging me. Frits said about a CVT used on a race bike that instead of using regular curved slots in the rear pulley that the slots should be perpindicular. I can visualise how the curved slots type of variator transmission works. With straight slots the rear pulley will only be affected by the centrifugal force on the rollers at the front working against the spring at the back and there will be no response to load. It will therefore be purely speed sensitive. I have trouble seeing how it will maintain an engine at a more or less fixed RPM though. What I envisage is the ratio increasing as the engine rpm is increased. I may just be having trouble getting my head around it but it seems to me that the slots would have to be curved to make it load sensitive for it to work.

I have thought it would be better to replace the contra spring with some sort of hydraulic cylinder and control that with the ECU. The hydraulic cylinder could have a small bleed to allow it to leak down, simulating a weakening spring, thereby allowing the CVT ratio to rise, or, as the ECU detected engine revs below set rpm with TPS indicating an open throttle the pressure could be increased using a PWM controlled valve making the cylinder force the rear pulleys closer pushing the CVT to a lower ratio. The hydraulic hose would fit to the end of the shaft with the clutch on it and the fluid under pressure fed through drillings to the cylinder in place of the contra spring. This setup would use straight perpindicular slots and the ECU could contain a map to make the CVT do whatever you wanted. Only a small oil pump would be required as the cylinder volume would be small and the amount of movement would only be 5mm or so. This would only need small volumes of fluid to be pumped to control the CVT.

[husaberg]

It's been bugging me. Frits said about a CVT used on a race bike that instead of using regular curved slots in the rear pulley that the slots should be perpindicular. I can visualise how the curved slots type of variator transmission works. With straight slots the rear pulley will only be affected by the centrifugal force on the rollers at the front working against the spring at the back and there will be no response to load. It will therefore be purely speed sensitive. I have trouble seeing how it will maintain an engine at a more or less fixed RPM though. What I envisage is the ratio increasing as the engine rpm is increased. I may just be having trouble getting my head around it but it seems to me that the slots would have to be curved to make it load sensitive for it to work.

I have thought it would be better to replace the contra spring with some sort of hydraulic cylinder and control that with the ECU. The hydraulic cylinder could have a small bleed to allow it to leak down, simulating a weakening spring, thereby allowing the CVT ratio to rise, or, as the ECU detected engine revs below set rpm with TPS indicating an open throttle the pressure could be increased using a PWM controlled valve making the cylinder force the rear pulleys closer pushing the CVT to a lower ratio. The hydraulic hose would fit to the end of the shaft with the clutch on it and the fluid under pressure fed through drillings to the cylinder in place of the contra spring. This setup would use straight perpindicular slots and the ECU could contain a map to make the CVT do whatever you wanted. Only a small oil pump would be required as the cylinder volume would be small and the amount of movement would only be 5mm or so. This would only need small volumes of fluid to be pumped to control the CVT.

he said axial..... i am not sure but if you go though my links there is something about a curvature and step where and profile changes i am not sure if that helps though. But he mentioned wiuthout the curved slots it then needs a much stronger spring which i guess is a result of not using the curved slots and it then relies heavily the spring pressure to work.

[wax]

Alot of scooters have a angle change in the ramp this allows them to upshit fast in the last half of there speed increase. This means that the revs drop and it makes for nice smooth runing road scooter. Straight cut ramps on the torque driver, Not straight up and down but a straight slot hold the engine rpm at set point ( hopefully max power).
the curve makes it very hard if not impossible to get this right as it changes the torque drivers effect on the spring and also the rate at which it changes up.

The ultimate goal is to have no variation in rpm from the start to the finish of the speed run. This cant happen in reality as once you get to the top of the variator the engine will have to over rev as there is no more gears to throw at it. I also set my clutches to come in right on the power band and this tends to flare the clutch a bit as you gas it up hard in a take off. But it does make them get off the line hard.
You can put a bigger sprocket on the front of the bike and there for keep the variator from making it to the top as soon this will hold the bike on the power longer asuming you have the power to pull the high speed

[Frits Overmars]

Frits said about a CVT used on a race bike that instead of using regular curved slots in the rear pulley that the slots should be perpindicular.

I said axial. But from the rest of your post I gather that you too meant axial.

With straight slots the rear pulley will only be affected by the centrifugal force on the rollers at the front working against the spring at the back and there will be no response to load. It will therefore be purely speed sensitive.

Right

I have trouble seeing how it will maintain an engine at a more or less fixed RPM though. What I envisage is the ratio increasing as the engine rpm is increased.

Right again. There has to be a small rise over the rpm range, maybe 200 rpm, for the primary centrifugal governor to cover the entire ratio range.

I have thought it would be better to replace the contra spring with some sort of hydraulic cylinder and control that with the ECU...........

It might even work. But I'd like to remind you of the KISS-principle: keep it simple, son.
There used to be (and maybe still is) a set on the market to replace the curved dish plus rollers in the primary pully of a Piaggio scooter with a thrust bearing on a ramp, very smartly controlled by the electric starter motor that lives there anyway. It was even possible to still start the engine electrically. This set was Italian-made but I don't remember the name; I saw it about ten years ago.
A button on the handlebar gave the opportunity to select seven ramp positions, so you could 'shift' at will, like with a priceless seven-speed seamless shift box. But it would be logical and fairly simple to let an ECU continuously control that ramp.
Come to think of it: the Suzuki Burgman 400 scooter has something similar.....

[Buddha#81:Me]

Fark what a mess.........even guys wandering off the track as the leaders come round for their first lap. Lots of ways for that to go real wrong!

[Bert]

Fark what a mess.........even guys wandering off the track as the leaders come round for their first lap. Lots of ways for that to go real wrong!

my god...
That requires a bit of a re think for future application.

[Henk]

my god...
That requires a bit of a re think for future application.

Has been discussed. From now on the "pusher" will only be able to hold the bike until the rider grabs it. Will give the two strokes a bit more of an advantage and will probably spread the feild out a bit more, not a bad thing really.

[jasonu]

>

What a cluster fuck! How come the bike holders are allowed to help push and thus end up in the middle of the track? The 2hrs I have been involved in had the holder standing on the grass and HOLD the bike, and the rider did all the pushing.

[TZ350]

How come the bike holders are allowed to help push and thus end up in the middle of the track? The 2hrs I have been involved in had the holder standing on the grass and HOLD the bike, and the rider did all the pushing.

This pushing thing is the way I remember them but I have heard that is going to change for next year.

The way I hear it, the riders are going to have to push start their bikes themselves, with no kick or electric starters allowed.

Guess how easy it is to push start the Beast. ...