03-04-2013, 03:39 AM
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#1 (permalink)
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Techomage
Join Date: Feb 2013
Location: Brisbane
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clutchless gear shifting ...
I've been trawling the lists, looking at EV conversions, and seeing people make the clutchplate into a shaft coupler (ie no more clutch).
So it occurred to me having pondered this.
If we grab the speed and "which gear are you in" information, the speed control microprocessor should be able to match the engine speed to the road speed "pretty closely" and make shifting gears pretty painless.
If the road speed and the motor speed are matched, the mesh will allow the shift to happen smoothly.
The controller would have to make some assumptions about whether you are shifting up or down, based on accelerator positioning.
Andrew.
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03-04-2013, 09:01 AM
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#2 (permalink)
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Master EcoModder
Join Date: Oct 2011
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Few years ago I was driving VW Scirocco MKII, and I've noticed that I don't have a clutch anymore. It turned out later that the shaft that was disengaging clutch went through the bearing. Anyway I was like 300km from home so I continued driving. The only problem was a full stop situation, because I needed to use starter with first gear engaged. After that I was driving without any trouble shifting gears up and down without clutch.
It's not so hard to so if you'll listen to the engine and match engine speed to the gearbox speed at the given gear. So I don't think that clutchless setup for EV conversion will be a problem.
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Gerhard Plattner: "The best attitude is to consider fuel saving a kind of sport. Everybody who has enough money for a strong car, can drive fast and hit the pedal. But saving fuel requires concentration, self-control and cleverness. It's a challenge with the nice effect of saving you money that you can use for other more important things."
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03-04-2013, 12:26 PM
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#3 (permalink)
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Corporate imperialist
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I have been no-clutch shifting up through the gears for years.
All you have to do is learn.
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03-04-2013, 01:20 PM
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#4 (permalink)
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Master EcoModder
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Well, most Americans dont know how to drive a stick.It will slip right into gear when you match the rpms of the input shaft to the gear.
My father loved the vw type 17. He had a few of the cluch release push rods weld to the release bearing, thus making his car clutch less.  |
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03-04-2013, 04:25 PM
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#5 (permalink)
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aero guerrilla
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e·co·mod·ding: the art of turning vehicles into what they should be
What matters is where you're going, not how fast.
"... we humans tend to screw up everything that's good enough as it is...or everything that we're attracted to, we love to go and defile it." - Chris Cornell
[Old] Piwoslaw's Peugeot 307sw modding thread
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03-05-2013, 07:41 PM
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#6 (permalink)
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Techomage
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I think you'all missed the point. It's not about whether clutchless shift is possible, but about making driving easier and cutting down the syncromesh wear and tear, by getting the computer to match the roadspeed(s).
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03-05-2013, 08:34 PM
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#7 (permalink)
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Master EcoModder
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I believe that how a few of the newer automatics from vw and honda to name a few work. They use regular gears and match the rpms before moving the shift forks into place. I think the chevy hhr has a no lift shift on the manual models that allow clutchless shifting once you start off. 
Quote:
Originally Posted by anderwgray
I think you'all missed the point. It's not about whether clutchless shift is possible, but about making driving easier and cutting down the syncromesh wear and tear, by getting the computer to match the roadspeed(s).
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03-05-2013, 08:58 PM
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#8 (permalink)
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Master EcoModder
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It's hard to do in an electronic throttle vehicle. The revs hang way too long.
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03-05-2013, 11:30 PM
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#9 (permalink)
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Master EcoModder
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Quote:
Originally Posted by Cobb
I believe that how a few of the newer automatics from vw and honda to name a few work.
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Not the VW ones. The DSG has two clutches, a computer works them both for you.
-soD |
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03-06-2013, 10:08 AM
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#10 (permalink)
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Master EcoModder
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Just took the sidekick for a spin in the white stuff. I used the clutch for first, then brought the engine up to 3500 rpms, then it slipped intothe next gear a second later. When the rpms match it will slip right in. Dont shift like those kids you see on youtube, take a second and pause in nutral between strokes.
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