Sorry for swearing - but thinking of fitting an 8 speed auto on my scratch build. Logic being that it can take more torque than most manuals (ZF 8hp70) and will work well in 4wd configuration.
The SLR used a torque convertor auto, so woth considering as a possibility (used in far more mundane cars so can be found from cheaper cars).
Once the torque convertor is locked using the clutch I will effectively have a sequential tranmission, with quick but maybe not dog clutch speed changes.
After exhaustive searches on the internet I have a few question still unanwsered.

I understand that a combination of solenoid settings selects gear, but how do I find what combination selects each gear?
Is all the N, P, R, functions selectable by electrical means or is there mechanical input required for these modes?
Any other considerations?

Have come accross the megashift project which helped me get up to speed with the basics.

Thanks
Darren

modern automatic gearboxes are tied into the can bus system of the car and usually have a separate ecu to control the box as well. yes the controls are still hydraulic to select the different brake bands.
I suppose its not beyond anyone to build a control box that activates the solenoid's , however they may not just be simple to do
Ie: if modern boxes have 4 or more brake bands controlling epicyclical gear sets then they may be and probably are not just in sequence but in combinations ie: 1+3 and 1+4 ect
you would need to know the control sequence for it to work.
the only way to do that would be to monitor all controls in the box when in the original car and copy.

not 100% sure im correct , but I think I am . I stand to be corrected.

Found this :ZF PDF

Shows what order the valves need to be operated in.

Next fun and games is sorting an adapter plate for the bell housing.

Electronic control should not be a problem, have a pcb designed for an ecu, an additional one can be used to control this, or I might have enough spare pins to control it with the ecu. Just need to change the software operattion for it.

Still need to understand the wiring for the additional functions like lockup cluctch, sensors etc.

Thanks
Darren

another useful website here: ZF 8hp operation

Which seems to tally with the ZF PDF.

Thanks
Darren

After a bit more digging the control for the transmission is inbuilt into the casing. If I am to use it, i will have to build a control unit to interface with the valve block. Not impossible, but have to figure if it is worth the work!

Would it not be easier to use something like a scrap jaguar s type with a j gate, selectable box, you lose the gears but do get manual control or a BMW where you put the shift to the left and can knock up and down the gears?

What engine are you looking at BTW

[Edited on 14/12/14 by mark chandler]

Sorry for the late reply. The Engine I am loooking at is either a Lexus V8 or the Meceedes m119 5.0 V8. I think the BMW box you refer to is electronically controled.

I does seem to look like both manual and automatics optoins will have dificulties. Will need to check the width of the boxes too.
Will expand on that, just been busy so will write tomorrow.
Thanks
Darren