Thank you MaxPower, I have been scrounging scraps of information from here and there, and am pleased to be corrected. It sounds like HSV are having similar problems to us in sourcing parts for a decently strong manual 4WD system.
I too am old enough to remember the drag racers using "clutch-flight" transmissions. They replaced the torque converter with a manual flywheel and pressure plate, and fitted a manal valve body to the torqueflight transmission. All it needed was a special coupling to drive the automatic's oil pump off the back of the pressure plate. It was a very efficient and reliable system.
Something similar may be possible with the Toyota five speed 4WD auto box. Getting rid of the torque converter will make a very big difference to the effective gear ratios. It could even make for some pretty fast gear changes too, with or without the clutch.
The gearbox itself would be built to withstand the torque multiplication of the torque converter, and turn some pretty big wheels, so gearbox static torque rating would be especially high for both gears and internal clutches/bands as it is designed for the V8 in a heavy vehicle.
Being an electronically controlled gearbox means a whole lot of ways to control it are made possible, especially as I am an electronic engineer.
In theory at least, it should be fairly easy to try. Unless some better idea turns up. I am sure it would be sufficiently robust in a vehicle only half the weight of the original.
I too am old enough to remember the drag racers using "clutch-flight" transmissions. They replaced the torque converter with a manual flywheel and pressure plate, and fitted a manal valve body to the torqueflight transmission. All it needed was a special coupling to drive the automatic's oil pump off the back of the pressure plate. It was a very efficient and reliable system.
Something similar may be possible with the Toyota five speed 4WD auto box. Getting rid of the torque converter will make a very big difference to the effective gear ratios. It could even make for some pretty fast gear changes too, with or without the clutch.
The gearbox itself would be built to withstand the torque multiplication of the torque converter, and turn some pretty big wheels, so gearbox static torque rating would be especially high for both gears and internal clutches/bands as it is designed for the V8 in a heavy vehicle.
Being an electronically controlled gearbox means a whole lot of ways to control it are made possible, especially as I am an electronic engineer.
In theory at least, it should be fairly easy to try. Unless some better idea turns up. I am sure it would be sufficiently robust in a vehicle only half the weight of the original.
