Shorter & uprated Springs

[bobbrown]

If I have the figures correct then the spring rates on the standard springs are as follows

1 N/mm = 5.710146 lb/in
Front 290 lb/inch
Rear 150 lb/inch

so the uprated fronts fed spec must be 360 lb/inch

Bob

[Monty]

What about dimensions bob

[bobbrown]

What about dimensions bob

I did not measure them, Eibach gave me the figures to replace the standard springs with 70mm race springs as a direct replacement.
A little confusion at their end as they had not spoken to Rob at Eibach as he is the head guy and they thought I was just replacing standard for the same but at least it gave me the standard rates.
Of course length is dependant on the shock length and pre load

[bobbrown]

I know it has been awhile since this thread was started and things may have seemed to have stopped but they have not.
My research with Eibach continues and they have come up with a spring setup for the Elan for fast road/track use, this setup can not use the current dampers as it uses race dual race springs.
e.g. a helper spring and a main spring
So with these spring settings and the suspension specifications they have take a walk down the road to Bilstein for them to supply suitable dampers to match the car and the springs specified by Eibach.
As these were the two companies along with Lotus who did the upgrade on the Esprit you can confident this is going to be a “proper job”.

Bob

[Nige]

Thanks for the update Bob. This is the development I'm really interested in (amongst the many) and as far as I'm concerned it takes as long as it takes to do it 'properly'.

[bobbrown]

I think the delay was partly down to the work load of Eibach had at the time with people like Lotus, Roll Royce etc and thrown into the pot was the fact that Rob is leaving and Greg from Bilstein is taking over his position.

I am hoping things will move forward a little quicker now.

[dapinky]

Good news on the progress!

I have great confidence in the two companies involved, and have used both on other projects.

I still believe that Bilstein are the leaders in their field, and (as others on here have mentioned) when it comes to low volume stuff for Post Historic rallying, i have never had a request that they cant produce, at a good price, for an excellent unit.

(if my advertising gets noticed, i would like another pair of Dolomite forest spec front dampers, please!!!!)

[bobbrown]

Good news on the progress!

I have great confidence in the two companies involved, and have used both on other projects.

I still believe that Bilstein are the leaders in their field, and (as others on here have mentioned) when it comes to low volume stuff for Post Historic rallying, i have never had a request that they cant produce, at a good price, for an excellent unit.

(if my advertising gets noticed, i would like another pair of Dolomite forest spec front dampers, please!!!!)

I agree completely.

The great advantage I see with this setup is that springs and shock rates can be changed, so you can go for the setup with the same specification as standard or you can increase the spring rates to a full race spec with the shock to match the spring rates.
As I am thinking inverted monotube shocks these can be valved to the correct specification to match the springs or if you change the springs then they can be re-valved to suit the new springs.
I am trying to steer clear of adjustable shocks as I do not feel they will give the best results.
It is worth noting that it is the spring that absorbes all the loads the damper is there to control the spring motion, so if a spring of a particular rate is fitted and the weights are know then the shock ratings can be calculated and the shock valved to suit.

This is the kind of setup a works team would fit to a race/rally car, but it does not have to be jaw breaking.

[Elanlover]

Bob, is there any special consideration needed for the Fed cars? The stock Fed setup has the car sitting slightly higher than the UK version. I don't know if there are any geometry diffrences that go with the slightly higher ride. I've had Protech shocks installed onthe front and back along with new UK springs (including SJ's stiffer version) which allowed the car to be lowered. So, I'm just thinking that, if there is a diffreence between the Fed and UK setup that needs to be taken into consideration then there may be two scenarios here. One for people who want to keep the stock FED ride height and one for those wanting a lower height (like me). If people choose to go with a lower ride height are there geometry changes than need to be made. Thanks!

[bobbrown]

The Fed cars are slightly heavier than the UK cars due in the main to the additional weight the crash structure imposes
The Fed cars are longer than the UK ones and the rear end is different again a crash structure issue.
The Fed cars have a slightly higher ride height (so I am lead to believe)
That is what I believe to be the main differances, if I have missed something someone is welcome to correct or add some comments.
As far as the suspension is concerned, I do not think the weight differance will effect the cars that much, probably LGM driving it against some big fat bloke driving it will effect it more.
If the ride height has been altered then the static geometry needs to be checked and is done at mid laden ride height e.g a 75kg driver and 1/2 tank of fuel.

The setup I am looking at lowers the car slightly (15mm) so as far as the Fed cars go it will probably lower them a little more, if this is undesirable or not allowed for any reason (I do not know what the regs are over there) then it should be easy enough to get them built so they retain the original ride height.

I will have a lot more detail once Bilstein have done their bit, I am hoping that this follow the set up that they did for the Esprit, OK this does not have direct input from Lotus.
I always feel Lotus tend to think of our Elans as a bit of a black sheep since they sold the rights to Kia.

I always found it strange when I was envolved in rallying, people would go to great lenghts to get the weight of the car reduced and then some big bloke would get in to drive it. He could have saved all that money spent on reducing the weight of the car and gone on a diet the results in weight reduction would have been higher at less cost.

Bob

[Elanlover]

Thanks Bob. At this point, with the car lowered to UK specs, I've had the rear wheels rub the liner a couple of times on hard cornering on the rack. That's with UK spec, OE springs and Protech shocks. I'm not sure how much lower I (not that I'm speaking for the Fed gang in any way) would want the car to go over what its is now. I can always provide some measurements if you want or perhaps they are in the manuals? (I think some are for sure).

I always feel Lotus tend to think of our Elans as a bit of a black sheep since they sold the rights to Kia.

Not everyone, Mike Kimberly was practically weepy eyed as he chatted breiefly with me about the M100 at the Hethel event. It was one of his favourite projects.

[bobbrown]

May sound a little silly but you did fit the bump stops?

[Elanlover]

May sound a little silly but you did fit the bump stops?

Huh?

My dear Bob, by now you must know that there are just some things I don't know much about. This is one of those areas I let the Lotus dealer install them. They seem nice and stiff relative to the stock setup. However, on this track day I attended there was a requirement for an instructor to come along on the first lap session. Sadly for me, I got stuck with Sumo Joe who easily weighed in at 250 lbs + Add my 195 to that and I'm sure we were getting close to Lotus' max combined passenger weight. Seemed we only rubbed when the weight was transferred to his side though...............

Track day was cut short that day and i didn't get a lap on my own to test it further.

[bobbrown]

It is possible that the weight in the car was part of the problem, but the car should be capable of the suspension going to full travel and not foul the body.
The only sure way to check this is to remove the springs + bump stops and lowerer the car (with the wheels on) and see how much clearance there is. If it does foul the body raising the ride height will not fix it, as the full bump is still the same (assuming the spring does not go coil bound) one simple solution is to fit taller bump stops.
I suppose to check they did fit the bump stops is to check the original setup to see if they are still there and if they are check the damper rods on the car at the top should be a cotton reel of rubber.

[chrishewett]

Just an update on my own suspension project.
Andy Waters has my car in his workshop and has had the new springs and dampers made. He will be fitting them with adjustable platforms and doing the cornerweight and geometry thing soon. I have told him I am not in any hurry to get the car back so I don't know when I will be able to test out the new setup but I will write up in full what he has done and the results as soon as I can.
Chris

[Nige]

Look forward to it Chris, thanks for the update.

[Monty]

Just an update on my own suspension project.
Andy Waters has my car in his workshop and has had the new springs and dampers made. He will be fitting them with adjustable platforms and doing the cornerweight and geometry thing soon. I have told him I am not in any hurry to get the car back so I don't know when I will be able to test out the new setup but I will write up in full what he has done and the results as soon as I can.
Chris

Good work Chris

Once it`s all done will it be possible to get the spec on the springs etc? ie spring make, size, length and rating

Cheers
Jay

[chrishewett]

No problem, I will do that.
I also intend booking a trackday at cadwell and taking Andy along if he agrees ( hopefully getting some valuable tuition as an added extra). If I can arrange it I will post details so anyone interested can see the results for themselves.
Chris

[Specky]

Chris,

A quick question if I may, it sorta links to something "Ex Fastcat" said a while ago...

have you changed any of the suspnsion bushes

Keep up the good work, I hope all goes well...

TTFN

[chrishewett]

Specky,
I spoke to Andy today and he tells me that he is having suspension bushes made. He will make these available as he has done for the MR2 ( he looks after the MR2 race series).
The car should be finished in two weeks. I can't wait!
Chris