Racing gearbox options.

[661]

This thread has come about because of the helical close gear group buy.
I want to build a FIA accredited race car. Yes, it may go on the road occasionally, but the primary aim is the track.
Would these helical gears do the job or is it straight cut all the way? I appreciate straight cut may be noisy if used on the road but that would be a surmountable issue. Strength and function would be the most important issues. I have only used a dog box on a couple of occasions so I suspect a synchro straight cut is the most likely weapon? Am I right?

[batfish]

Hi Graeme

All FIA spec race Elans that I have have been involved with use straight cut gears. Dog boxes are specifically not allowed in Elans running to FIA appendix K specification but that does not mean that some Elans are not running them.

Andy

[rgh0]

I have run Quaiffe syncro straight cut gears for many years. It is time for a gearbox rebuild and I am planning to try the MKF helical cut ones this time. The only real difference is the thrust loads with the helical gears but the casing and thrust bearings appear OK in the Elan box to handle this up to the level of Torque loads in racing in the intermediate gears.

The advantage of the helical ones is I can use them on the road once I retire from racing without having to put up with the straight cut gear noise.

cheers
Rohan

[661]

Thank you to both of you.
I appreciate that most racers would use straight cut and I had been informed that the box 'must' be synchro'd.
However, If you think these helical gears are up to some unskilled abuse ( but mainly pampering) and 180bhp then they may be worth a punt.
The ratios would seem about right by my understanding and the company have a good reputation. Is it worth getting the gears polished/coated or whatever it is they do to optimise strength?

[rgh0]

Some people get gears cryogenically treated and micropolished as additional treatments. The degree of improvement in gear performance or life appears to be limited versus the cost involved so I have never done it.

cheers
Rohan