3 replies to this topic

[Jonty]

can someone tell me what the difference between a straight cut gear box and a original is please as im not sure and i would like to understand this thanks

[hawky443]

I would love to know the same thing. I remember a comment from an old mini enthusiast saying " kids and there straight cut short shift these days" I just smiled as if I understood lol! Please someone enlighten us.

[Artful Dodger]

a straight cut gear box is no different to a normal gearbox, apart from the gears themselves. the gears are 'straight cut' instead of 'helical cut'. This means that the teeth on the gears are straight rather than angled. this is to help the transfer of power through the gearbox as the standard helical gears produced lateral movement because of the way the teeth were angled.

another reason they used helical gears as standard is that they didnt produce that loud whine you hear on racing cars, they were quiet, which is why most manufacturers use helical gearboxes.

[Cooperman]

The straight-cut gear sets currently available are all of much closer ratio than the helical boxes. This is because the straight-cut gears are designed for use on competition Minis where a much hotter cam will be fitted with a narrower power band. So, when fitting a SC gear set a lower final drive is normally fitted to avoid problkems with clutch slipping when pulling away. 1st gear is very high with the SC CR gears.
Fitting a SC CR gear set to a car with a standard engine will remove a lot of flexibility for driving on normal roads and, with the lower final drive, will reduce cruising speed at given revs.