Close ratio value??

PostPost by: nomad » Sat Nov 14, 2015 4:43 pm

A friend traded his close ratio box for a semi close and a set of 3.55 rear gears. The box was going to a racer. Is this an option or did he just get lucky??

I'm thinking I may like to do the same.

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PostPost by: elanfan1 » Sat Nov 14, 2015 7:08 pm

A c/r box must be worth at least 5 times that of a semi so by my reckoning the other guy got the great deal.
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PostPost by: nomad » Sat Nov 14, 2015 11:25 pm

OK, Steve. I appreciate that and now have a better idea. Just the expertise I was looking for! :D

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PostPost by: Quart Meg Miles » Sat Nov 14, 2015 11:44 pm

I have the impression that nearly all early 26s had the close-ratio box with 3.9; mine did and I love it on the open road.

I once changed the diff to 3.54 and it felt bogged down all the time though I think a more powerful engine would overcome that. However, a semi-close box with 3.54 would allow the engine to rev more in the lower gears while still leaving the higher top speed, oops, I mean lower revs at the speed limit.

I've had the 3.9 back in since 1990; it feels right but my trips nowadays don't usually exceed 50 miles non-motorway.
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PostPost by: nomad » Sun Nov 15, 2015 3:54 am

I've experienced 3.9s in Sprite's and Midgets and don't have a problem with that gearing on US two lane roads. Roads that I really enjoy driving, but it seems that anywhere I go I encounter much higher speed limit's. South Dakota has just raised its interstate highway speed limit to 80mph!
So, I'm still on the fence to some degree but hope to have a rolling chassis, at least, by spring so need to make some decisions.

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PostPost by: dlbutler » Sun Nov 15, 2015 7:52 pm

I've recently built a close ratio gearbox with all new parts to replace the worn out C.R. box in my S4. To help judge the value of a close ratio gear box I've added the cost for the new parts including shipping: $3100 (before my shop discount). I bought a good used case for $50 so I could assemble the box without disabling my Elan.
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PostPost by: nomad » Mon Nov 16, 2015 1:47 am

Meg has got me wondering. I have to do some calculations considering the power curve of the early 105 rated engine. I don't remember what the 5th gear ratio is in the Datsun box that I have in my Midget but I believe that with the overdrive in that box and my 3.9 rear gears in that car that the final ratio end's up close to the 3.55 final we are talking about on the Elan. With the Midget 65mph is 3500rpm.

Where can I find a plot of the power curve for the 105hp TC?

Meg's claim that the high gears turned his stock engined S1 into dog is something I have to consider.

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PostPost by: Mazzini » Mon Nov 16, 2015 9:12 am

I run a close ration box in my S3 with a 3.5 diff. The car has a 135bhp engine and it's a pleasure to drive, yes it lacks the "squirtability" of a low geared Elan, but then the car will cruise on motorways at 80mph+

If that doesn't appeal why not try a fitting a 3.7 dif?
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PostPost by: rgh0 » Mon Nov 16, 2015 9:18 am

dlbutler wrote:I've recently built a close ratio gearbox with all new parts to replace the worn out C.R. box in my S4. To help judge the value of a close ratio gear box I've added the cost for the new parts including shipping: $3100 (before my shop discount). I bought a good used case for $50 so I could assemble the box without disabling my Elan.


I presume you fitted straight cut gears from Quaiffe? I was not aware that new helical cut close ratio gears to the original design are available?

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PostPost by: Mazzini » Mon Nov 16, 2015 9:26 am

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PostPost by: rgh0 » Mon Nov 16, 2015 9:32 am

Looks good - I need to build up a spare box for my Elan as the syncro in my current box is dying in third gear.- looks like i may try this gear set.in one of the spare cases i have rather than getting another Quaiffe gear set.

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PostPost by: jono » Mon Nov 16, 2015 10:12 am

A close ratio gearset recently sold on Ebay for ?205.

I didn't even bother bidding but would have happily paid twice that, or indeed more.

Recently MFK engineering were listing new helical close ratio gearsets for ?1,350 (10 available) but the listing disappeared. I was tempted.

Quaife do them as sc sets for around ?1050 but you may not want that in a road car?

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PostPost by: jono » Mon Nov 16, 2015 10:14 am

soz, just seen the previous post - I see they are back from MFK!

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PostPost by: gjz30075 » Mon Nov 16, 2015 10:40 am

Jono, this one?
http://www.ebay.com/itm/LOTUS-CORTINA-L ... true&rt=nc

He says close ratio in the title but also says it has a 2.97 first gear in his text.
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PostPost by: jono » Mon Nov 16, 2015 10:45 am

...good spot Greg, that explains the price!

A good job I didn't bid!

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