The Lotus Grand Tourers

I'm hoping that since this is effectively just a "servo" on the original rack it will be OK. You can also program the amount of assistance it gives. I'm also making the caster adjustable at the front to help optimise the self-centring effect of the geometry.

Only time will tell!

Pete

I suppose I'd better get something done if there's going to be the remotest chance of getting to LITP next year in it!!

This is the gear selector lever/mount I've fabricated to keep the whole assembly low-profile (to avoid the "hump" like in the Excel):



The cable is mounted using two small rod ends to allow it to pivot as the inner cable is pulled backwards - this reduces the stress on the (very stiff) inner cable.

You can just about tell from the photo that the lever - in the vertical position - is about 1" further back than the original manual stick:



Still have to decide on the cosmetic finish around the lever - whether to make a gaiter like the original manual or make something more like the Excel (BMW) cover. I need to include a gear indicator whichever way I go.

The bowden cable needs to be 4" shorter than in the Excel!

Next I'm going to tackle modifying the throttle pedal to activate a drive-by-wire pedal position sensor and build a mount for said sensor - a Variohm motorsport unit. First thing to do is to make the throttle pedal removeable without having to take the pedal box out first!

Pete

Lovely piece of engineering.
Seems a shame to cover it up? They didn't in the later Elise / Exige.
- But it could be a bit drafty .

Tony

That looks superb Pete. Nice one

Fantastic engineering Pete. Really elegant solutions to problems and I love the way you put so much thought into the details.

Shaun

Can't wait to see it in the flesh at LITP next year

Thanks guys! I've got the bit between my teeth again on this but it's still going to be difficult to get it done - or at least driveable - for next summer. I'm going to try though! I've designed the chargecooler and got the core on order - being made for me by Pro Alloy. I've nearly finished the serpentine drive belts - I'll post up some photos soon. I know which ECU I'm going to use - waiting for a price on that. I've bought the drive-by-wire throttle body and supercharger bypass valve. I think I've found a good inlet plenum - need to get it slightly modified - and I've got a local company 3D printing some inlet manifold spacers to experiment with before finally getting them made in aluminium. Getting there!

Pete

Nice machine work Pete!

Have you installed any rubber boots/seals under the mechanism or is it all already sealed - there was a rubber cover on my SA? A Perspex gear lever cover to show off your work would be good - it would be a pity to hide it all away

Neil.

The cable exits through a boot and of course there is a foam gasket on the transmission tunnel but nothing actually covering the underside yet. I want to look at making a custom rubber "boot" for the underside but I've never done any rubber moulding! . Any ideas? There must be some kind of self-vulcanising liquid out there.

Pete

Hi Pete, I also need a boot to go over the bottom part of my gear lever so have given his some thought, but without finding a definitive answer just yet! I may adapt a CV joint cover or steering rack gaiter if they will work.

You do get 2-pack silicone that cures to a rubbery consistency that would work I'm sure - it's often used for mould making. You would need to make a mould and use a product that's not very runny, and maybe reinforce it with material??? Or you'd need to be able to pour it into a mould that would form the entire shape, but that could be a lot of work to make unless you have a standard sort of shape to make - like 2 bowls inside each other as a mould.....

The stuff they use for body/face moulds may work - something like this dragon skin https://www.smooth-on.com/product-line/dragon-skin/ - I see you can build up layers of it.

Neil.

I'll have a closer look at that - thanks. It would have to end up with the inside and outside pretty smooth and consistent as it would have to form the gasket for the transmission tunnel as well. Needs more thought!

Pete

First trial assembly of throttle pedal position sensor on pedal box:



The small aluminium block has a sealed double row ball bearing in it and the Variohm sensor is driven by an 8mm D-shaft. It's programmed to go full range with 90deg of rotation. You can see the new nylon removeable bearing blocks that support the throttle pedal and allow it to be removed easily. The whole assembly is driven by an extension welded to the original throttle pedal leaving the top as original to operate the auto gearbox cable. The whole assembly will have a cover over it eventually.

Pete

Great engineering. Looking forwaard to seeing it some day.

Nice work Pete.
There's not alot left in that picture of the pedal box that Oliver would recognise. !!
Tony

Lots of work involved in that - think I'll make the Lexus pedal work as it is in my car! A mounting bracket will tax my brain a lot less than all that geometry

Neil.