In which the author confesses himself to be an ass

[jbcollier]

I have an early 395 tranny in my S1 and I have to confess that it has not performed as well as I expected.  I was quite excited because the ratios were nice and close. It turns out they "are" close, in some ways good, in other ways, too close for comfort.  The early 395s have a 3.4x first gear which is much better than the later 395’s 3.8x  — some of the NGs have over 4.xx!  So that’s good.  The spread between 1-2, 2-3 and 3-4 is all good (not perfect but good) but 4-5 is far too close together.  It only drops about 500 rpm.  If you do a slow, leisurely shift, it feels as though you have selected 4th again.

The ideal solution would be a final drive of 3.5x as in a 336 (395 et al comes with 3.7x), and a 5th gear ratio in the 0.7x range.  It’s not possible to change the final drive but it is possible to have custom gears made up, albeit at a high price.

Has anyone had custom gears made up?

How did it go?

Anyone you would recommend?

[4129R]

I believe 5th gear on the gear knob is marked as O/D, standing for overdrive.

Triumphs used to have an overdrive switch on 3rd and 4th, which was another set of gears which just dropped the revs slightly.

You are not supposed to accelerate in O/D, but just cruise at lower revs, saving petrol. Well that was the theory in the 70's when they had O/D.

[jbcollier]

I was briefly excited when I found an Alpine 364 final drive with a ratio of 3.3x (bit tall, true) but then, duh, I remembered an Alpine final drive would give me 5 reverse gears.

One yahoo member has posted that the 365 5th will fit in a 395.  That might drop 5th a few more 100 rpm.  I wonder if the 0.78 from a later NG will fit?  Probably not as things that are too good to be true, generally are too good to be true.

[TCS4605R]

Instead of having (5) reverse gears, move the ring gear from one side of the gearbox to the other.  Back in the Formula V race days, that is what you did with a VW gearbox - the VW gearbox is in front of the beetle engine, the Formula V gearbox is to the rear of the engine.

Tom
TCS - 4605R

[jbcollier]

I don't think there is the space to do that.  Would have to check and make sure first.

[Grumblebuns]

It might be worthwhile to contact Wayne Mitchell at Dogrings.com. He specializes in Hewlands but he does custom make stub axles and uprights, not sure about alternate gears. He was the one casting and machining the custom Type 47 magnesium uprights a few years ago. I'm currently using him to machine a couple of high balance intake manifolds for my TCS. It helps that he lives an hour away from me.

http://www.dogrings.com/products.html

[jbcollier]

I have his axle replacements.  Haven't installed them yet.

[blasterdad]

Found this by accident... (Morning coffee /computer routine, ).
http://www.ebay.com/itm/A074F6117Z-Lotus-Europa-TC-TCS-5th-synchro-for-365-gear-set-/162239204898?hash=item25c635ce22:g:48QAAOSwARZXpL3X&vxp=mtr

[jbcollier]

That's not the gears.  It's the selector and hub.

[andy harwood]

I think it was Valerio, posted a couple years ago about having some gear sets machined. Don't remember the details.

[jbcollier]

That was a close-ratio, straight-cut 4 speed for racing.

[Rosco5000]

What is your current tire size, Could you up the diameter so you could get a perceived ratio change?

[jbcollier]

Absolutely but it won't change the spacing between 4th and 5th.