Lotus Elan

S4 front Ride height

PostPost by: holywood3645 » Fri Jun 19, 2015 10:32 pm

I have read many old posts on this subject, with various views.

My S4 is high at the front. The control arms are not level witht he ground and the stanse look wrong.
I bough some adjustabel platfrom Spax. The spring that were sold to me are;
19 coils
.325 wire dia
65 lb/in
15.5 inchs long
Wnen fitted to the shock, the car stills sit way to high.

Can anyone advise me the correct length for the springs prior to fitting on shocks?

James
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PostPost by: worzel » Sat Jun 20, 2015 8:37 am

Hi

That's very interesting- I recently posted a question about the opposite- I'm using 75lb front springs (apologies for previously quoting the poundage as 85)-. Springs are 16 inch long free and my car- a std bodied fhc sprint with no accident damage sits too low!

Another odd point- the sill to ground distance is 6inches so theoretically the overall ride height should be correct- but it isn't and this car has definitely never been accident damaged as I was acquainted with the first owner when I bought it in 1978. The tyre to wheelarch lip is less than one inch.

I'm not familiar with your suspension setup but maybe it's wound up to maximum- others will no doubt know more on this.

Regards

John
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PostPost by: rgh0 » Sat Jun 20, 2015 10:04 am

Standard front springs are as follows

75 lb/in
19.6 coils
0.324 inch diameter wire

free length 16.08
fitted length 9.22 inch

A longer spring of the same rate at 16.75 inches free and 9.86 inches fitted was supplied for some markets

James
Your springs appears to be near correct dimension at 15.5 inches and I presume the 65 lb/in is an error. The adjustable seats should allow you to set the correct ride height. Recognise if you don't have standard diameter tyres the ride height will change. What is the fitted length of the springs when the car is on its wheels - does it match the 9.22 inch specification?

John
Your springs again appear to be standard specification. Check you spring fitted length with the car on its wheels to see if its correct. If you have the 6 inches under the car with standard tyres then your clearance is correct . Why do you say it is not? You appear to be concerned the wheel to arch gap is to little why do you think that?

cheers
Rohan
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PostPost by: worzel » Sat Jun 20, 2015 11:54 am

Hi Rohan

Thanks for your comment. The reason I believe there is a problem is that I recently cracked the wheelarch when turning into my drive (at a walking pace incidentally) and the driveway is not "ramped" in any way. The other wheelarch has also made contact with the tyre at some stage as I've just noticed two cracks about a half inch long on the lip of the arch- these have probably resulted from an earlier journey when I entered the driveway from the opposite direction to mu usual route and I heard the tyre scraping on the arch but didn't give it much thought.
As I said in another post the tyres are 155/80/13 so no huge bits of rubber causing the problem and the springs (obtained from P Matty earlier this year) are the std 75lb poundage. I've recently renewed the rubbers between the top of the spring/damper assembly and the front tower (with harder rubber) but this has made only a marginal difference.


Regards

John
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PostPost by: rgh0 » Sat Jun 20, 2015 12:23 pm

Hi John
The standard size tyres will hit the lip of the front wheel arch when turned and you hit a bump on the inner wheel or the car rolls in that direction. Its just the way it is. Many Elans show some cracking from contact in this area.

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Rohan
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PostPost by: Galwaylotus » Sat Jun 20, 2015 6:45 pm

My belief is that ride height is only applicable with the original tyres at factory pressure and new factory spec springs. What should be checked is the lower A-arm which should be parallel to the ground. This should be the case no matter what tyre and pressure so that design suspension geometry is maintained,
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PostPost by: holywood3645 » Sat Jun 20, 2015 7:11 pm

Ok, a few more details
I have the shocks/springs that came with the car before restoration, (not sure type/spec)
I have a set of Gas SPAX (just found out one has lost charge) that i have tried to fit and adjust but have same initil too high issues, as old setup. Old setup is now installed.
15.5
3.25
19 (full) coils
65 lb/in (its correct and recently measure over a 2 inch travel)

Floor to cross member height is 7in (see picture)
Control are are not parallel to ground (see picture)
tires are 155x80x13 on minilites.

The Spax are jut over 10 in on coil (see picture)
ride height is just under 24inches to lip. (see picture)

Any ideas?

Now I dont know if i should dump the Spax adjustable gas completely, and buy ??? (different shocks...AVO) or just order another Gas Spax. Any suggstions? I dont see good reviews on the SPAX

Thanks

PS I agree with my fellow Irishman, Galway Lotus on the control arm, but i think need shorter springs to get there.
Attachments
To lip.JPG and
To chassis.JPG and
Spax.JPG and
Last edited by holywood3645 on Sat Jun 20, 2015 7:21 pm, edited 1 time in total.
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PostPost by: Galwaylotus » Sat Jun 20, 2015 7:20 pm

One thing I noticed in your most recent post is that you are using gas dampers. They provide an additional spring rate that must be considered. I don't know the figures but the total spring rate must include both the rate of the coil spring plus the rate of the gas dampers.
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PostPost by: collins_dan » Sat Jun 20, 2015 10:04 pm

I have the TTR adjustable set up with 175-70s. Control arms are flat. Height under front sills is 5.5" and under crossmember is 6". My driveway is elevated and requires turning to enter and this works fine. Dan
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PostPost by: holywood3645 » Tue Jun 23, 2015 4:37 am

Any other ideas?
James
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PostPost by: rgh0 » Tue Jun 23, 2015 9:20 am

The front suspension diagram in the work shop manual ( Fig 1 Section C) shows dimensions between the top shock mount and the bottom shock bolt at normal ride height, full bump and full droop - have you checked what dimensions you have ?

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