What Transmission Type in a Nissan R90CK?

[Alfatipo]

Got bitten by the Raceroom Group C leaderboard challenge.

Apparently the transmission is manual but seems to auto select Neutral after a stall.

Is the clutch required for every change other than starting or stopping?

Nissan site states that it is a VGC transmission but I can't locate any other information.

Any help appreciated - Jef

 

[Emery]

Nissan site states that it is a VGC transmission but I can't locate any other information.

The VGC is a Hewland transaxle that was used in several race cars of the period, such as the Mercedes C9, so pretty much a dogbox.

The C9 ran a Hewland VGC box, which says Briggs, ‘was really the Achilles heel on the car.’ VGC internals are still available and there are companies that manufacture replacement parts.
The only real challenge is the crown and pinion gears, explains Briggs. ‘They use a palloid cut on the gears. The regular VGC has a pair of taper roller bearings, which are preloaded, and has Gleeson type gears with tapered teeth. The palloid cut gears are parallel cut, which allows for a degree of float and they run on angular contact bearings. But palloid cutting machines are very expensive, so most people use Gleesons. The palloid is better and can accommodate more wear.’

Edit: some Hewland history of VGC
DGB 1981 Sportscar endurance. Full oil system, strong case.
VG 1981 As DGB concept but bigger.
VGC 1986 Uprated version of the VG.

 

[Alfatipo]

Wow! Thanks Emery. No syncro then? Could be why I don't always get the next upshift. Downshifting is OK

 

[Denis Gicquel]

Wow! Thanks Emery. No syncro then? Could be why I don't always get the next upshift. Downshifting is OK

Missed downshifts can also happen with this car, especially if you try to skip gears with an H-shifter.