9 replies to this topic

[Mini1275]

Does anyone have a straight cut gearbox in there mini on here? I would like to know just how loud they are and does it feel any different to a normal gearbox? Could you also tell me the advantages, ive heard there stronger and more efficient, is that correct?
Thanks

[Turbo Nick]

http://www.bud666.pw.../video-0002.wmv

just a little vid taken on my mates phone but you get the idea. Also got a bit of turbo/dump valve noise on there.

I'm really pleased with my SCCR box. I love the long 1st gear you get with the cluban gearsets and then it just stays on boost after each gear change

[vasi]

[Mini1275]

thanks for video, anybody get anymore? Im looking at buying a new mini and its got a straight cut gearbox I like the noise but I dont want it to be too loud and Im travelling pretty far to see the car.

[Purple Tom]

when the BH2N dvd is finished I'll be able to show a video of a lap of the nurburging from inside my car, with sc box and drops....but it'll be a little while I'm afraid.

[siggy]

S/cuts are no stronger than helical gears.

Noise is not too bad unless it has s/cut drop gears

Siggy

[Sprocket]

S/cuts are no stronger than helical gears.

Noise is not too bad unless it has s/cut drop gears

Siggy

Well i was under the impression that the gears are made from higher grade material. Straight teeth eliminates the side loading which saps energy as the helical gears try and push themselves appart sideways. The more load you put through the gearbox the more energy goes side ways and ends up as heat. not only this, but the standard casing cant take the extra sideways load.

This is more so with the transfer gears. it is realy these that make the majority of the noise rather than the box itself.

Extreamly powerfull engines will rip the teeth quite easily off the first gear and or final drive pinion if not before the drive shafts shear.

[The Matt]

I was thnking this too Minisprocket. The helical cut gears must lose power due to the side load in the bearings. I didn't know it was a fact, more of a guess, but it looks like I was correct for once.

Also, assuming the same material is used for the helical and straight cut, I would have assumed straight cut gears had less surface contact, so in the case of the same material grade being used for both gearsets, straight cut would be weaker???

I am currently thinking of going to SC in my Mini (when I have saved up the cash) and would love to hear peoples opinions like above.

Oh, and Bud666, me like the vid! :wink:

[Guess-Works.com]

Oooh.. the debate hits town again and I realy cant be bothered to go through it again...

IMO, if you want to run high performance motor, then you need SC gears basically as they are designed for high performance motors, there are currently no manufacturers of helical high performance gears for the mini. A std gearbox is designed for an engine delivering standard power, and for logevity of service...

If you're using a helical box on a high powered engine... look to replace the gearbox, and transfer casing fairly frequently, as you idler will be pushing a big dent in it.

[Turbo Nick]

yup guessworks is spot on, i'm only running around 130lb/ft with my engine and it saw off a standard turbo dox and idler gear, aswell as the transfer and gearbox casings in under 1000 miles, hence the full SCCR box/drops/4 pin diff now its torque that kills em rather than bhp i believe.