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Automatic upshift for BECS ?
zilspeed - 9/3/08 at 02:40 PM

I've been thinking - not good, but bear with me.

Seeing as bike engines / gearboxes have dog engagement, no synchro and sequential shifting they lend themselves to clutchless shifting, hence the flatshifters we see now.

Similarly, we have kliktronic for replacing the gear lever with buttons or paddles.

We also have shift lights built into many of the current breed of digital dashes.

To me, the next logical step is automatic upshift.

Engine reaches change up point as last shift light goes on, flatshift system cuts ignition, kliktronic type system engages the next gear, ignition comes back in. All without driver intervention.

Downshift would be manual unless someone can tell me why not.

I can see this as being worth a bit of effort for use in hillclimbing and sprints in particular where the ability to just pin the throttle out of a corner and just concentrate on steering without having to even think about gears.

Any thoughts anyone, or has it already been invented ? (apart from F1 where it has already been banned as a driver aid too far)


smart51 - 9/3/08 at 02:53 PM

Entirely feasible and also very good in that you get the fastest possible acceleration. A couple of points though, The best revs to shift, on a carbed R1 at least, go down with each gear. You want the maximum 11750 in 1st but less in 2nd and less still in 3rd because the gears get closer together and peak power on mine is at 10100 RPM.

The other problem could be unexpected shifts mid corner where you could provoke lift off oversteer.

Smart ForTwos from 2004 have automatic upshift at the red line but they also use the lateral accelerometer (g meter) from the ESP. If you're cornering too hard, it won't up shift and will let you bounce off the rev limiter if you forget to shift yourself.


pathfinder - 9/3/08 at 03:36 PM

Aprilia are trying it out on the Mana 850


http://www.diseno-art.com/encyclopedia/vehicles/road/bikes/Aprilia_Mana_850.html


TimC - 9/3/08 at 03:51 PM

quote:
Originally posted by smart51
Entirely feasible and also very good in that you get the fastest possible acceleration. A couple of points though, The best revs to shift, on a carbed R1 at least, go down with each gear. You want the maximum 11750 in 1st but less in 2nd and less still in 3rd because the gears get closer together and peak power on mine is at 10100 RPM.

The other problem could be unexpected shifts mid corner where you could provoke lift off oversteer.



You are right of course Colin, but many of us will have been to trackdays and either got caught out ourselves or heard others bouncing off the limiter so to set it at the redline would be worthwhile. My old CBR1000 car had only a 10250 limit but because it felt like it would go to 12000+ I used to get caught out. I think it's the most sensible idea I've heard all day. However, I have been revising 'Organisational Behaviour' so that might explain it!


tks - 9/3/08 at 04:45 PM

its as easy as dell..

but some times you want to short shift..

and thats where it comes in handy...

Tks


MikeR - 9/3/08 at 06:09 PM

so we need to add an additional break in the wire, something connected to the steering column, if the column isn't straight ......... no shift.

(although this would mess up if you over cooked it and had to counter steer, as you moved through from left to right it would upshift ..... so we add a capacitor so you have to be straight ahead for a second or two).

i'll go back to celebrating Wigan's 'win' against arsenal (win being defined as not losing)


zilspeed - 9/3/08 at 06:31 PM

quote:
Originally posted by pathfinder
Aprilia are trying it out on the Mana 850


http://www.diseno-art.com/encyclopedia/vehicles/road/bikes/Aprilia_Mana_850.html




That is a cvt (according to your link ) which really has to be computer controlled to give a manual or auto mode.

Thinking further, the output from the shift light could be used to trigger an upshift event on the kliktronic, no doubt.

As regards shifting mid corner, I keep hearing about how the flatshifter system, once set up correctly, will not upset the chassis when used manually. Don't see why automating that should change this benefit.


hobbsy - 9/3/08 at 07:31 PM

There is already an off the shelf gear change system that has this.

In fact I've got it but not got around to fitting it yet!

Its a Techtronic something or other.

Reminds me I need to find a wiring diagram for it as I bought it 2nd hand and while I can take an educated guess (using a multimeter) I can't be sure what are the wires are!

I'm not sure I'd use it on track though.

I might fit a dash mounted switch.

Could be useful for drag racing but it might take some of the fun out of it, and after the start its not as if you've got much else to concentrate on! Was considering launch control for this as well... I fitted the Racelogic traction control system to my S14a 200SX and it worked well. Sounded cool too, like WRC starts!

http://www.techtronicsracing.com/


hobbsy - 10/3/08 at 09:32 PM

I was telling porky pies, its not techtronic its translogic (sounds kinda similar), this fella:

http://www.translogicuk.com/tls-ps2-sports.htm