Author Topic: TMH 5th gear ratio  (Read 1552 times)

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Nigel hpe

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TMH 5th gear ratio
« on: 27 December, 2024, 10:35:02 PM »
Hi all,
I'm aware that TMH used to supply an alternative 5th gear ratio that was 0.780:1 as opposed to
the standard 0.925:1

I'd like to find out the teeth count on this pair of gears. A photo of same would
be a huge bonus.

Nigel

A1.6HPE

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Re: TMH 5th gear ratio
« Reply #1 on: 30 December, 2024, 12:30:19 AM »
Is this referencing the Beta VX transmission?
I believe that some cars have been fitted with VX transaxles in order to get a more relaxed cruising speed.

Leo
Edinburgh Regional Co-Ordinator

peteracs

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Re: TMH 5th gear ratio
« Reply #2 on: 30 December, 2024, 08:09:02 AM »
Hi Leo

The TMH mod was for any Beta gearbox, not just the VX, it raised the gearing on the 5th gear only. The diff ratio remained the same. You are correct that you can fit a VX gearbox/diff as that had the highest ratio of diff used, the gearbox ratios essentially remained the same over all the Beta range.

Peter
Beta Spyder S2 pre F/L 1600
Beta HPE S2 pre F/L 1600

Nigel hpe

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Re: TMH 5th gear ratio
« Reply #3 on: 30 December, 2024, 06:08:33 PM »
Is this referencing the Beta VX transmission?
I believe that some cars have been fitted with VX transaxles in order to get a more relaxed cruising speed.

Leo


Hi Leo,
I already have a VX box in my 2000 carb HPE and the result has been excellent. The performance has not
significantly reduced and cruising is much quieter, I've now got 3000rpm at 70mph.
If I could drop that even slightly more I'd be interested.

I've now read that US spec Betas had a 5th gear ratio of 0.865:1, possibly a nice mid-way point.

Peter, I think you're using a VX box in your build?

Regards to both,

Nigel

peteracs

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Re: TMH 5th gear ratio
« Reply #4 on: 30 December, 2024, 11:05:32 PM »
Hi Nigel

Correct, will be interested to see what you find out about the US one.

Peter
Beta Spyder S2 pre F/L 1600
Beta HPE S2 pre F/L 1600