Motorcycle Engine with Powershifter Help

[Knick]

Hey all, I'm very new to this and need guidance.

I am in a FSAE team and we are planning to use a motorcycle engine and installing it with a powershifter. We want to use buttons to shift rather than a clutch. We want to have a our button shift act as a shift assist, so that when we press the buttons to go up and down, the engine will shift at its optimized rpm. However, I have to come up with a solution/design that will act as a clutch in order for the gears to shift up and down.

What can I do? I'm really new to this so I'm clueless. Anything will help and I'll try to answer any confusions that I have given.

If this is a bad idea then what would be a better alternative?

[spam2128]

You could use a pneumatic solenoid and cylinder to actuate through gears. Your ECU should have an ignition cut to calibrate shift without lift.

If you're a new team, or inexperienced in this area, why not use a simple linkage? Many teams have problems with pneumatic shifting. It's not much fun to have something go wrong and you're stuck a single gear.

[Jon Burford]

Yeah, you won't need to touch the clutch if you do it correctly.
You can shift any gear without the clutch if you know what your doing. Bikes are great, lift a little and tug and you'll fly up through the box.
as spam said, most ECU's will at least have a shift cut function which is activated either by a switch or a strain gauge. It will cut the ignition as the gear is changed to allow you too keep your foot flat on the throttle, (Flatshifting), the system is normally called shiftcut.

[Freddie]

There are both electric and pneumatic systems that you can buy "off the shelf" and run with, we used an electric one for our -13 car. For the clutch we just had a lever that the driver used for starts, and we had no clutch during the rest of the driving. It's not perfect by any means, but if you can afford it it's a viable solution. Just make sure that your electrical system can handle the power output if you go for it.

[Jay Lawrence]

Just run a manual shifter as Spam suggested.

Think of it this way: a paddle system will shift quicker (if done right) and will save you up to maybe 100ms per shift. This may equate to 1s over the course of a lap (assuming 10 upshifts), but this 1s does not come off your lap time (you aren't standing still while you change gear). Let's assume the system takes 3 days to install, program, and get running right. That is 3 days that could be used training your drivers (with a manual shift), and that WILL save you seconds per lap. Plus you avoid all potential reliability problems with your tricky shifter. If you really must have ignition cut shifting (once again, not necessary), you can install a strain gauge on your shifter linkage (just remember to keep it calibrated...)

[Knick]

Thank you all for the help. I will look into everyone's suggestions.

[jlangholzj]

Originally posted by Jay Lawrence:
Just run a manual shifter as Spam suggested.

Think of it this way: a paddle system will shift quicker (if done right) and will save you up to maybe 100ms per shift. This may equate to 1s over the course of a lap (assuming 10 upshifts), but this 1s does not come off your lap time (you aren't standing still while you change gear). Let's assume the system takes 3 days to install, program, and get running right. That is 3 days that could be used training your drivers (with a manual shift), and that WILL save you seconds per lap. Plus you avoid all potential reliability problems with your tricky shifter. If you really must have ignition cut shifting (once again, not necessary), you can install a strain gauge on your shifter linkage (just remember to keep it calibrated...)

they also make sensors that can go in-line with the linkage that can be used for ign cut. Packaged nicely and would eliminate the strain gauge hassle.