Lotus Elan

Kelsport 5 speed gearbox

PostPost by: batfish » Tue Feb 18, 2014 2:27 pm

Interesting new item from Pat Thomas at Kelsport, 5 speed gearbox , not sure about the suitablility of dog engagement for road use though

http://www.kelsport.net/news/story.asp?ArticleID=134

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Andy
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PostPost by: rcraven » Tue Feb 18, 2014 2:56 pm

The 1:1 ratio in 5th doesn't suggest it's designed for relaxed cruising at speed.
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PostPost by: CBUEB1771 » Tue Feb 18, 2014 4:08 pm

The problem is that the span of ratios from 1st to 5th is basically the same span as is provided by the 4 speed semi-close ratio gearbox. So this really only makes sense for competition use. If the first gear was more like 3.6:1 and the other ratios spread suitably then the fifth gear ration of 1:1 would not be a problem, we could just use a taller final drive ratio.
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PostPost by: batfish » Tue Feb 18, 2014 4:23 pm

from the ratios and the dog engagement this has to be a competition gearbox, trouble is it would not be allowed in FIA Appendix K specification cars.

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PostPost by: msd1107 » Tue Feb 18, 2014 9:39 pm

I remember the announcement of this gearbox.

However, it seems to be neither fish nor fowl. A dog box is dodgy for use on the street, and the intermediate ratios can be improved (2nd closer to 2.03. 2nd closer to 1.52). The 3.04 1st is good for the road especially if matched to a taller final drive (Said by one who drives a CR trans with a 3.55).

For pure racing, 1st gear is too low and the intermediate ratios could be improved. For rally usage the overall ratio is OK, but the intermediate ratios could be improved. It seems to have been used by several manufacturers (maybe even in the Elan) but Lotus never homologated it, so it would be difficult to try to use it for racing today.

This appears to be an early Hewland design, and they have learned quite a bit since then.

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PostPost by: pharriso » Tue Feb 18, 2014 10:12 pm

Isn't it more interesting that on the same web page they are announcing an alloy bellhousing so a T9 can be used?

Also mention they are developing "a new tail housing to fit the gearbox into a Lotus Elan, This will allow the gear lever to be in the correct position"

Now this I could go for!
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PostPost by: patrics » Thu Feb 20, 2014 7:36 pm

Hi,
The 5 speed 2000e box was at the Autosport show it's made by [email protected]
I think it was about ?3000

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Steve
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PostPost by: vstibbard » Tue Mar 04, 2014 11:56 am

I spoke to the guy who had the gear set made and modified the casing at the show, there is only one box complete at moment, its about to be tested in a sprint/rally car and feedback used to finalise the build and fettling.

He purchased a number of the old Hewland made 5 speed 2000e boxes and has designed solutions to the limitations. It was beautifully made, with helical gears so quieter than the Quaife straight cut, and modern designed dogs are amazing to use, you just have to be positive with your changes.

Modena Engineering in Australia made some 5 speed gear sets for a bullet gearbox, different selection mechanism as they were for an Escort that raced in historics over here about 10 years ago. Franks products are beautifully made, all gears interchangeable, dog engagement, caged roller bearing etc, about A$5000 built.

I agree with the comments regarding the ratio's, 1:1 top I'm almost fine with as it allows a 3.55 to be used, be better if there was such a thing as a 3.3 or 3.2 ratio, but the intermediate steps were not that inspiring, I'd have preferred something between the semi close first and the 2.5 first in the close ratio, the closely stacked ratios to 1:1 or slightly overdriven. I discussed this with him and he said ratio variations could be accommodated up to a point, as there are dimensional limitations to fitting it all in!

I'm thinking of a 1860 to 2.0 litre Kent blocked TC, steel bottom end, 3.55 low diff ratio with LSD and one of these... hmmmm food for thought.

Cheers V

Cheers

V
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PostPost by: bigvalvehead » Tue Mar 04, 2014 8:26 pm

Hi Vaughan
I am going the T5 route with the Turbo engine I am building.

You can buy an ex TVR or Camaro T5 gearbox (these have the stick in the correct place for an Elan) for around ?500 and they are bullet proof.

The bellhousing to suit the T/C is around ?180

So a much cheaper alternative than anything else.

Ratios are good with 2.93 1st and .83 5th.
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Dave
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PostPost by: gjz30075 » Wed Mar 05, 2014 11:33 am

Dave, where did you source the bellhousing?

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PostPost by: vstibbard » Wed Mar 05, 2014 12:38 pm

HI Dave and they obviously take high torque and HP.

I'll drop you an email

Cheers

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PostPost by: bigvalvehead » Wed Mar 05, 2014 7:19 pm

Hi Greg
Link to website for bellhousing
http://www.rwdmotorsport.com/bellhousings.html


Cheers
Dave
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