Lotus Elan and Lotus Elan Plus 2 Forums

Thanks Rohan,

Test day yesterday at our local (short) track went well. Even though I am not really up to speed I already notice inside wheelspin coming out of the tightest left hand turn, even with it being an LHD car. The straight is not long and I was being very conservative with the braking point, so it never approached max RPM in 4th. I will have the car at the longer circuit next week so will see then if it tops out with the current gearing.

For general interest, I looked up SCCA production specs (attached) for the car which lists a 'standard' set of ratios and then 3 'alternate' sets, one of which is 2.97/2.01/1.4/1.00 so that must be what I got in the car. Also there are 3.55, 3.77, 3.90, 4.12, 4.43, and 4.7 diffs of which I must indeed have the 4.43. Oddly enough the spec weight is listed as 1470 lbs (667 kg) which seems a bit ambitious given the curb weight of over 1900, I think, for the road car. Hopefully I will be able to weigh the car next week.

Overall I am very happy with the general feel of the car, it was great to get it out finally and string a few laps together. I've never raced a production car on tarmac before (just single seaters, long ago, and one or two paved rally stages) but am pleasantly surprised, the car feels light, goes where it is pointed, and makes all the right noises.

Cheers,
Kevin

Sounds like a total disaster to me - you should sell while it is still shiny - ideally to me!

People, I have seen this car and it will initiate embarrassing drool when you get close enough.

The owner forunately knows how to drive cars of this type in the manner required so...all I can say is, that an appropriate dashcam be attached.

Circumstances (and - more importantly - a total lack of the talent required for driving such a car in the manner intended/required) prevented my from wading in on BaT when it was up for sale but - if I had the money, if I had had the money - I would have bought this car, just to occasionally and discretely brush against it.

It is sublime.

Cannot wait to see it unleashed...

Hello all, I wonder if this thread is still alive .... perhaps I'll start it again over in the racing section.

Back in the before-times, right after my last post, I took the car to Pacific Raceways for the Novice orientation day. It was indeed geared too short with the 4.44 diff, so I was touring down the straight, and generally short-shifting. Nevertheless in the second session there was a click and a buzz, and it went onto 3 cylinders. Removing the cam cover revealed pieces of the #2 inlet lifter lying about and the cam lobe somewhat damaged from directly whacking the top of the valve stem. Peering down the plug hole revealed divots in the top of the piston. No overrev or missed shifts, it just went pop.

So after much procrastination and pandemic border closures, I finally got the motor apart and dropped off at John McCoy's (Omnitech). The valve had broken, and wedged itself sideways in the port. John is familiar with the cams that were in it, said it was quite a bit of cam (more like they would use in a Formula B build), and figures the previous builder did not leave enough clearance between the IN and EX valves.

So, while John sorts that out I am shopping to upgrade the rest of the drivetrain. I'll get the diff assembled with the Quaife LSD I got in a box with the car, and a 4.11 ring and pinion.

Also John suggests a straight-cut race gearset so I am debating between the Quaife close (2.5:1 1st) vs. ultra-close (2.25:1 1st), and dog vs. synchro. Although my focus won't be the tight track at Mission, perhaps the 2.5 first would make it more driveable there.

So when John is done let's say it is a 180 bhp/8000 RPM motor. I have spreadsheeted the speed in gears (see attached) with the various choices and with my 14" Hoosier tires (23" unloaded diameter), 2.5 1st & 4.11 diff would give around 30 mph 4500 RPM where the torque comes in, and topping out at 133 mph, 8000 RPM. Does that sound realistic? Maybe a bit boggy at Mission Turn 3, but should work through the 3A-3B section at Pacific.

I'll probably get all the parts from Tony Thompson Racing (TTR).

I'll change the Rotoflex halfshafts to the U-joint set from TTR. Any thoughts or alternatives on this?

Do you think I'll need to upgrade the output shafts in the diff? The existing ones are stock (it seems), 3 bolt.

Any thoughts on dog vs. synchro? I'm not too concerned about adapting my driving to a dog box, but am concerned about reliability, both from the 'box itself and the rest of the driveline.

Cheers,
Kevin

Sorry about the engine failure but John should be able to build you what you need if anyone there can A formula B style motor in a much heavier plus 2 is totally the wrong way to go especially if the builder did not know how to get the valve train right which is not easy with high lift long duration cams and big valves.

Focusing on the drive train reliability is a good place to start !

A straight cut Quaiffe gear set is the way to go, synchro versus dog is a matter of personal preference as both work and are reliable if built right and used right. Many race drivers appear to destroy their gear boxes quickly by abusing them and forcing changes.

Hard to advise on gear and diff ratios without knowing the tracks but I would expect a 4.1 to work with most tight tracks and 4.4 to be a bit short even on tight tracks.

Quaiffe LSD is good, When rebuilding the diff with the LSD use the longer ARP bolts to ensure proper engagement as the diff carrier flange is a little thicker than the original.

New diff output shafts and new wheel hub shafts are needed as you can break both on tracks with sticky tyres and a strong motor.

I personally would fit CV drive shafts rather than the TTR UJ and spline units if your racing regs allow.

cheers
Rohan