Lotus Elan

Oversteer on corners

PostPost by: JonB » Wed Apr 24, 2019 5:36 pm

So, let's go back to this problem momentarily.

I've been thinking that my problem might be because the car is rolling too much in the bends. Sure feels like it. I wondered if the Aeon springs were missing or damaged, so I took a boroscope out into the garage and shoved the business end up the rear suspension, under the dirt shield.

img_5480.jpg and
Offside 2


img_5479.jpg and
Offside 1


img_5478.jpg and
Nearside 2


img_5477.jpg and
Nearside 1


They look OK to me...
Late 1972 Elan Plus 2S 130/5 - UK - Unit 50/1115L
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PostPost by: JonB » Wed Apr 24, 2019 5:38 pm

Next thing I am wondering about is the roll bar bushes. I've not done mine as it is a known pig of a job. Might loose or worn bushes contribute to the problem? They would certainly cause the rattle I'm getting over the bumps.
Last edited by JonB on Wed Apr 24, 2019 8:35 pm, edited 1 time in total.
Late 1972 Elan Plus 2S 130/5 - UK - Unit 50/1115L
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PostPost by: 69S4 » Wed Apr 24, 2019 6:19 pm

JonB wrote:Next thing I am wondering about is the roll bar bushes. I've not done mine as it is a known pig of a job. Might loose or warn bushes contribute to the problem? They would certainly cause the rattle I'm getting over the bumps.


I've changed the roll bar bushes a few times on my S4 and I wouldn't put the job in the 'pig' category by quite some distance. Yes it needs a bit of effort /concentration/ care but unless there is something odd about the +2 roll bar it's nothing to lose any sleep over.
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PostPost by: Foxie » Wed Apr 24, 2019 7:25 pm

Foxie wrote:
661 wrote:I measured my spyder rear toe in recently and I have zero. As they are the 'upgraded' oval profile it would be difficult to weld an adjuster to them, and frankly for the fuss I'd like to do camber too. So it looks like a trip to Mr Wallet.


Forgot to mention, the rear camber was mad wrong also, but the Spyder adjustable top arm fixed that.

Have to say that the rose joint was not up to resisting accelerating/ braking forces and I had to fit brass collars (Conex Instantor !) to prevent the rose joint outer rings from coming out of the end eye. The original rubber bush was ok. I contacted Spyder about this but never heard back. :(


Just saw this reading back through the thread. Just an update on this. Spyder got back to me and supplied a pair of uprated rose joints later last year. All good since. :)
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PostPost by: mbell » Wed Apr 24, 2019 9:38 pm

If you take the time to clean and paint the roll bar, with a bit of lube the bushes slip on quite easily. I could see fitting them to a dirty rusted up bar would be much more difficult.
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: JonB » Sun May 05, 2019 5:39 pm

OK, it's on the list!

Now, about the cornering and roll steer. I came to the conclusion that A arms aside I should replace the Aeons in the rear suspension and fit the spacers if they are not present. This should stop the car rolling so much, and I think this is contributing greatly to the overseer.

Another point. I have commented about the vagueness the car has in a straight line at speed. I had thought caster was the problem, as my car has very little of it. Since I am running smaller tyres fitted by the PO (165 70 R13) it seemed to me that fitting the correct diameter tyres (186 80 R13) might help, as it would move the steering pivot point further away from the contact patch, thus allowing more leverage for the limited castor force to act with. A theory, anyway, so if it's wrong, let me know. So I looked at some old threads to see if I could find a reasonable tyre recommendation that wasn't going to cost an arm and a leg. Whilst reading these I saw a comment about the tyre pressures being pretty critical and so out I went to check them. Way too hard - 30/28 front/rear. Reduced them to 22/25 and the car seems to be rock steady in a straight line now. Who'd have thunk it?
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PostPost by: Grizzly » Mon May 06, 2019 11:54 am

JonB wrote:How can they be toed out when there is no adjustment?

It's surprisingly common for the rear arms to be bent, it's often caused by people jacking on them after seeing the picture in the manual. If they do get bent it messes up you rear geo.

I have been having some odd things going on with my rear suspension too, turned out mine was a mixture of bad damper and aeon springs (i fitted solid bump stops instead of aeon springs by mistake). With those both fixed and a pair of Col's risers the handling is WAY better.
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PostPost by: vincereynard » Mon May 06, 2019 6:00 pm

JonB wrote: Way too hard - 30/28 front/rear. Reduced them to 22/25 and the car seems to be rock steady in a straight line now.


So you had the front pressures higher than the back? :o Maybe thats why your steering was light!
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