Hi Chris,
I am the designer of the CIMA transaxle. In order I think that we should have a collaboration in state of a competition, please take note of my suggestions.
1) Perfect choice for the differential but without preload. Between 2.5 and 3 of torque biasing is the best in traction, and an honourable 5 to 6 in coast mode. ( feasable if Mike jumps in the case )
2) Lovely choice about driving the oil pump through the secondary set. It avoids hard cold shiftings.
Let me know which synchronisation system you are using ( diameter and number of cones )
3) I would do it in 6 speed by keeping the same spread in order to help the synchros. The revs jumps are lower.
4) The biggest point which I do not agree at all, is the choice of isostatics shafts. I believe that the center distance is the historic 79 mm. With this value you definetly need a third bearing to transfer the torque you are claiming. Considere that the actual tyres are reaching 1.4 as grip coefficient. This means that the box is 30-40% more loaded then in the passed. I suppose that the gears fitted in the middle of the shafts are not helped by the tyre spinning. Try to fit a pulled support in the middle ( an eight with 2 bearings ). This will not avoid the torsion of the shafts but it will be very helpfull against the deflection.
5) Cut the input shaft in 2 parts.
A) Extremely helpfull in flexibility for meeting customer requirements.
B) If the first bit is made in 34NiCrMo16 fully tremped ( extremely tortional material ), this will cut the peaks of torque considerably, allowing a lighter gear design and.......allowing non damped clutches ( it is already a torsional damper if setted at 1° of torsion every 80 Nm ).
A non damped clutch has an inertia to be synchronised of about half of a damped clutch. The synchros will be so quick in responding to the shifting demands for the pleasure of the final customer.
If you do not mind, pls contact me for a private chat.
My details on
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