Manual trans questions

There are a lot of ideas here; and the following may not be the best. Nonetheless, I will offer the point that many BMW twins (motorcycles) use a dry clutch with a hydraulic master-slave set-up. I could imagine adapting those parts to an e3/e9 manual IF (really big if) the throw distance and force of the motorcycle system is sufficient. Hard to guess. One would still need to fit the hand lever to the steering wheel; but I have seen that done.
This might not be better than other options, but I consider it were the need to arise.


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Since you are escalating @D Calkins, another option for you.

Adapter plate, Getrag S55, custom ECU, and paddle
Me too!!

So the actuator is pretty simple. I assume there is a transfer function that converts applied voltage to linear motion. If it is just a solenoid, then the applied current would produce a force, and the resulting motion would depend onthe resistive force of the clutch. So that is the first hurdle to address. If it is really just a solenoid, then we would some sort of servo loop to change the current to achieve the acceleration we wanted, although that approach also introduced uncertainties related to how much accelerator pedal the driver is applying.

Another consideration is that disengaging the clutch seems easier than engaging it.

ALso, probably need to consider engine speed and accelerator position. You don't want to disengage the clutch with the trans in gear, and under load, or the engine will redline. So you will need a throttle position sensor, an accelerometer, and some sort of programmed engagement and disengagement profile, probably servo controlled.

IMO, you are overcomplicating it. You want the actuator to trigger via the lever. The lever is spring tensioned just like the clutch pedal. As soon as you let go of the lever it completely disengages. The actuator should match the position of the lever, which thereby implicitly matches the speed at which you arrive at any position. No sensors required.

You can already buy this as a kit. I sent it to @D Calkins earlier this week before he started this thread, but he apparently wants to build it himself.


If I wanted to do a similar project, I would go with a Getrag GS7D36SG 7spd DCT. My good friend is running one in his 4 rotor FD RX7, and his 3 rotor FD RX7 with paddle shifters. A handful of companies sell modules that interface with aftermarket ECU’s, and plenty
of companies sell the paddles. I helped install both and it is a beast of a transmission. One would undoubtedly need to do some firewall clearing and a new driveshaft is a given.

M30 adaptor:
 
Back to HB Chris, My 5speed is a little different then the usual. When I bought the transmission, it came without the Bell housing. When I got it home is when I found out the differences but I decided to surge forward. The throw out arm pivot ball is what turned out to be the difference. It was too tall and wouldn't fit behind the old bell housing.
So I cut back behind the old bell housing to fit the pivot ball stand to a plate bolted to the old bell housing. Been working now for three years. I will take a picture of it next time I do the rear main seal again.
Thank you.
Larry Louton
 
The DCT gearbox is huge and will require complete fabrication of the transmission tunnel. It make it a very big job. The advantage to a 4hp 22 is it bolts right up to the engine and fits in the tunnel. I looked into that but it was way more work. You also need to use the factory ECU which is not programmable on your phone.
 
The DCT gearbox is huge and will require complete fabrication of the transmission tunnel. It make it a very big job. The advantage to a 4hp 22 is it bolts right up to the engine and fits in the tunnel. I looked into that but it was way more work. You also need to use the factory ECU which is not programmable on your phone.

Agreed on all fronts but you definitely don’t need to use the factory ECU. That is a solved problem. Another thing though is that they are getting expensive and hard to find since so many JDM cars are using them now.
 
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