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turboswede
turboswede PowerDork
1/16/13 4:49 p.m.

Oh and Audi did something similar on their Group B cars:

http://classicmotorsports.net/reader-rides/1863/group-b-shifter/

If you look at in-car footage of the Group B cars on course, you'll see they aren't using the clutch to shift.

vwcorvette
vwcorvette Dork
1/16/13 5:59 p.m.

smart fortwo is 5 speed manual without a clutch pedal. Moving the shifter causes the computer to actuate the clutch.

The clutch actuator/motor is at the 5 o'clock position in the picture.

oldtin
oldtin UltraDork
1/16/13 6:44 p.m.
RossD wrote:
Giant Purple Snorklewacker wrote:
GameboyRMH wrote:
oldtin wrote: AP Racing has an off the shelf version. Costs $10k with a minimum order of 15.
Warn people dammit, I nearly had a stroke!
There can be no logical explanation for that except some idiot was willing to pay for it once before.
The kicker is that since the idiot payed for it once, he still had to buy 10.

When I talked to the AP rep - the gist was that this bit goes into a spec series and the whole field would running the same equipment. Since I wasn't running a series, he didn't have much interest in continuing the conversation. As a commercial enterprise, they probably wouldn't be too excited to turn these loose to joe public and the liability that comes with joe public.

GameboyRMH
GameboyRMH PowerDork
1/16/13 6:49 p.m.
vwcorvette wrote: smart fortwo is 5 speed manual without a clutch pedal. Moving the shifter causes the computer to actuate the clutch. The clutch actuator/motor is at the 5 o'clock position in the picture.

^Winnar!

Even if you need to reverse-engineer some communication protocol that thing uses, this is the easiest and best solution.

jstand
jstand Reader
1/16/13 9:56 p.m.
turboswede wrote: Oh and Audi did something similar on their Group B cars: http://classicmotorsports.net/reader-rides/1863/group-b-shifter/ If you look at in-car footage of the Group B cars on course, you'll see they aren't using the clutch to shift.

As long as you are using an ECU that supports "shift without lift", it isn't hard to instrument a shifter to activate it. Once the force threshold is reached on the shifter the ECU cuts the ignition for a set number of milliseconds to unload the gears allowing the shift to take place. Just don't rest your hand on the shift going down the straight, you may trigger the ignition to cut out.

I used to be involved with instrumenting shifters and linkages and the shift without lift was used by several of the sport compact drag cars and Champ cars in the late 2000's.

weedburner
weedburner New Reader
1/17/13 8:58 a.m.

How about using a brake booster on the clutch master?

Giant Purple Snorklewacker
Giant Purple Snorklewacker MegaDork
1/17/13 9:03 a.m.
GameboyRMH wrote: ^Winnar! Even if you need to reverse-engineer some communication protocol that thing uses, this is the easiest and best solution.

I'm not sure that is a better answer than using the SMG unit out of an E46 M3 unless the application is FWD (assuming you can reverse engineer to make it do your bidding). At least the BMW unit was designed around a sporting intention and can shift really quickly.

Curmudgeon
Curmudgeon MegaDork
1/17/13 9:54 a.m.
weedburner wrote: How about using a brake booster on the clutch master?

That's basically how VW did the Auto Stick. It worked but was kinda slow reacting.

Knurled
Knurled UltraDork
1/17/13 12:55 p.m.
turboswede wrote: Oh and Audi did something similar on their Group B cars: http://classicmotorsports.net/reader-rides/1863/group-b-shifter/ If you look at in-car footage of the Group B cars on course, you'll see they aren't using the clutch to shift.

They also tended to not use the pushbutton because it was too harsh. It was just an on-off deal controlled by power steering pressure. (The power steering also drove the alternator on some models - they put EVERYTHING they could in the back of the car!)

Careful which videos you're watching, too - some of the videos are of the prototype DSG transmission. Clutch pedal was only used to move from a stop.

turboswede
turboswede PowerDork
1/17/13 1:02 p.m.
Knurled wrote:
turboswede wrote: Oh and Audi did something similar on their Group B cars: http://classicmotorsports.net/reader-rides/1863/group-b-shifter/ If you look at in-car footage of the Group B cars on course, you'll see they aren't using the clutch to shift.
They also tended to not use the pushbutton because it was too harsh. It was just an on-off deal controlled by power steering pressure. (The power steering also drove the alternator on some models - they put EVERYTHING they could in the back of the car!)

I believe that. I think a combination of the push button solution with that air-powered solution could alleviate some of the issues with harshness since you can control the rate at which the clutch lever moves using different bleed valves.

Considering how nose heavy the Audi's are naturally, I'm also not surprised that they went to great efforts to move everything to the rear they could. They also had a computer to control the boost and ignition to try and keep the boost spooled all the time.

N Sperlo
N Sperlo UltimaDork
1/17/13 1:04 p.m.
oldtin wrote: I have a 1/2 gallon reserve tank tucked inside a fender and pressure switch for the compressor - so it's got a ready supply of 100 psi.

A friend runs one to power his two sets of train horns. One on each side under the bed.

OSULemon
OSULemon Reader
11/18/13 11:08 a.m.

Sorry to revive an old thread, but I found this:

http://www.youtube.com/watch?v=oiXnVl_KZ70

Thought it might be relevant to your interests.

dean1484
dean1484 PowerDork
11/18/13 11:39 a.m.

I like that BUT I did not see any technical stuff. I hope they don't use the 10K option

EDIT: I much prefer old thread revival as it keeps relevant information together.

Thingmaker
Thingmaker
2/18/20 8:40 p.m.

In reply to oldtin :

Hello oldtin. Could you please contact me regarding this mechanism? My idea is to use a tandem steering pump (e.g as used in mercedes 1990s '"abd" diff locks, or their "abc" body roll assist spring actuators, abc brake systems, etc)). A gear stick mounted trigger potentiometer would control a proportional valve (or throttle valve, or "high speed" valve as you mention) that actuates the push to release clutch slave. However, I haven't yet figured out how to release/bleed the pressure from the slave to engage the clutch. Any thoughts much appreciated.

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