Lotus Elan

springs and dampers

PostPost by: cadwell » Mon Jun 21, 2021 3:22 pm

I think this subject must have been discussed many times but I think I need some advice.
I am rebuilding an S4. Damper tubes were in an awful state so have removed these with the help of the family oven, and my 10 ton press. Uprights all vapour blasted and ready for rebuilding.
The car came with 2.5"id rear springs, and I am about to check the rate with my press and race car scales. However, I ran an Elan years ago with standard springs and thought the set up was wonderful, very comfortable with excellent cornering, but it was a few years ago and tastes change.
Standard are 75lb/in front and 67.5 rear I think, which do seem a bit soft.
It would be good to have a few experiences of standard springs and harder versions. I stress that I am interested in max comfort, rather than ultimate handling, so I am leaning towards keeping the standard set up unless someone convinces me otherwise!
Also dampers. Posts a few years ago criticised Spax dampers as being too hard even on the minimum setting, are Konis better? or Protech? or Gaz?.
Advice on front springs also welcome, my existing springs even on full extension are twisted, which does not fill me with confidence.
Thanks all
Peter
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PostPost by: elans3 » Tue Jun 22, 2021 3:49 pm

Difficult one this Peter, as it's so subjective. One man's perfect is another man's abysmal.
I'd agree with the comments about Spax, but I really haven't tried them for a long time, so perhaps I'm being unfair now. They were always too hard for my liking. I have Koni's all round on my Alfa, (Red adjustable), and set at half-hard at the front, and full soft at the back, are perfect for that car.
My S3 has Koni top adjustables at the back, set at full soft (They were from TTR , part number TTRSS008, (includes springs), by a previous owner).
At the front it has TTRSS041, (includes springs), again set at full soft.
When I bought the car back last summer, I found it too hard for my liking. I wanted the standard ride feel, and after a few adjustments, found that having them set at full soft gave me that condition. It now rides and handles like a good standard Elan.Both front and back are coilovers, which I have adjusted to get the stance I like too.
Hope that is of help, but as I said, its a bit of a minefield, as everuone's aspirations are so different.
Steve
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1963 Alfa Giulia Ti Super Rep.
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Elan S3 DHC S/E 1966
Elan S3 FHC Pre-Airflow 1966
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PostPost by: cadwell » Tue Jun 22, 2021 4:25 pm

Thanks for this Steve. Interesting that you find the ride ok with TT springs because I understand theirs are a lot harder than standard. Chapman’s philosophy was soft springs with hard dampers and I seem to be leaning in that direction.
I wanted to go back to 4” rear springs but cannot source any top abutment plates, so I may have to keep the 21/4 Id spring set up.
Fortunately there is an excellent spring manufacturer only a few miles from here (Matlock), so new original rate springs are no problem.
Peter
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PostPost by: RichardHawkins » Tue Jun 22, 2021 6:05 pm

Caldwell,

I bought top rear spring abutments from Spyder. This is probably 10 years ago. They are not an exact copy, being fabricated rather than the original pressed item, but seem to work.

Hope this helps,

Richard Hawkins
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PostPost by: mbell » Tue Jun 22, 2021 7:36 pm

I am just waiting for delivery on a TTR +2 setup. My hope is that they are not too hard, rear shocks are described as "Comfortable and fast pair". Worse case I can get softer springs or re-fit the standard springs.

TTR also sell the spring caps/abutments:
https://www.tonythompsonracing.co.uk/pa ... gs-plus-2/

They also sell thread tubes and lower abutments for the standard spring diameters rear springs.
https://www.tonythompsonracing.co.uk/pa ... r-springs/
https://www.tonythompsonracing.co.uk/pa ... d-springs/
'73 +2 130/5 RHD, now on the road and very slowly rolling though a "restoration"
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PostPost by: elans3 » Tue Jun 22, 2021 8:01 pm

cadwell wrote:Thanks for this Steve. Interesting that you find the ride ok with TT springs because I understand theirs are a lot harder than standard. Chapman’s philosophy was soft springs with hard dampers and I seem to be leaning in that direction.
I wanted to go back to 4” rear springs but cannot source any top abutment plates, so I may have to keep the 21/4 Id spring set up.
Fortunately there is an excellent spring manufacturer only a few miles from here (Matlock), so new original rate springs are no problem.
Peter

Ride is great with those springs Peter, as they are the "maximum comfort" spec, not hard at all. see link :-https://www.tonythompsonracing.co.uk/parts/steering-and-suspension/
So with those springs front & rear, and the ability to adjust the dampers, it gives me what I want, even though I didn't buy / fit them, it was a PO. Turned out good by accident.
Current :- Elan S3 DHC SE S/S 1968,
1963 Alfa Giulia Ti Super Rep.
Previous :-
Elan S3 DHC SE SS 1968,
Elan S3 DHC S/E 1966
Elan S3 FHC Pre-Airflow 1966
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PostPost by: benymazz » Wed Jun 23, 2021 3:30 am

I run AVO adjustable shocks and 95lb/in springs in the rear and TTR fast road/track day coilovers in the front (125-130lb/in I think). Ride is harsher than stock however I do not find it at all uncomfortable. The handling of the car is much tighter which is what I was going for - if you’re looking for a weekend cruiser rather than something to really slam through backroads with, the stock suspension is quite comfortable and does just fine. Chapman designed it specifically with long travel and low spring rates to make it as comfortable as possible and the amount of performance you can extract from it bone stock is impressive

You should be able to find 2.5” springs with a rate close to stock. Try Dave Bean Engineering.

Also worth noting that you can actually calculate spring rate of your existing springs without any fancy equipment like a press and racecar scales - all you need is a piece of paper and calculator, and to know the following information: diameter of the wire the spring is wound from, number of coils in the spring, diameter of the spring, and shear modulus elasticity of the steel. The formula to calculate the spring rate with that information can be easily revealed by a quick google search.

-Ben
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PostPost by: Frogelan » Wed Jun 23, 2021 1:14 pm

Ben,

Would it be possible for you to give the freestanding lengths of the springs you fitted please!

Your spec is pretty close to the original 26R specification and if it is not too much to ask, could you comment on ride height and the weight of 26/4623?

I have fitted the TTR (Gaz) front dampers as these are adjustable and within FIA rules. There are many flashy (spring) height adjustable ones but these are not homologated - the FIA know the spacer trick.

These seem to be very nicely made for TTR by Gaz (but only available through TTR).

Many thanks

Andrew
1965 Lotus Elan S2 26/4022 (originally Dutchess Lotus East, PA and NJ Area, USA)
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PostPost by: benymazz » Wed Jun 23, 2021 3:08 pm

Frogelan wrote:Ben,

Would it be possible for you to give the freestanding lengths of the springs you fitted please!

Your spec is pretty close to the original 26R specification and if it is not too much to ask, could you comment on ride height and the weight of 26/4623?

I have fitted the TTR (Gaz) front dampers as these are adjustable and within FIA rules. There are many flashy (spring) height adjustable ones but these are not homologated - the FIA know the spacer trick.

These seem to be very nicely made for TTR by Gaz (but only available through TTR).

Many thanks

Andrew


The rear springs have a free length of 12". I do not know the free length of the front springs as they came fitted on the dampers and I have had no need or desire to remove them

I am running an adjustable spring perch kit in the rear and with the perches on the lowest possible setting the car sits with 5.5" (140mm) of clearance as measured from the rear of the sill. The front sits a hair lower at 5.25" but with the adjustable perches on the TTR dampers could go from 4 to 6 inches if I so desired. I will probably try to obtain 11" free length springs for the rear as I want the car low (around 5") for track days and my observations are that having the front sit lower than the rear tends to induce oversteer that can become a handful braking in wet conditions

I have not weighed the car but it should be the same as the stock weight for an S2 plus or minus 20lb. I haven't done anything in that department (yet)

-Ben
1965 S2 26/4623
Life is like a sewer, what you get out of it depends on what you put into it.
"I'm never gonna financially recover from this"
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PostPost by: 661 » Wed Jun 23, 2021 4:14 pm

Frogelan wrote:Ben,

Would it be possible for you to give the freestanding lengths of the springs you fitted please!

Your spec is pretty close to the original 26R specification and if it is not too much to ask, could you comment on ride height and the weight of 26/4623?

I have fitted the TTR (Gaz) front dampers as these are adjustable and within FIA rules. There are many flashy (spring) height adjustable ones but these are not homologated - the FIA know the spacer trick.

These seem to be very nicely made for TTR by Gaz (but only available through TTR).

Many thanks

Andrew


I found the TTR 325lbs 8" front springs were too long to get the car to race ride height (610 Kg). The 7" springs worked well but are very close to rattling on full droop.
Graeme
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PostPost by: Frogelan » Wed Jun 23, 2021 4:28 pm

Thank you Ben and Graeme!

To just add my thoughts already presented above, I'm going to sit down and try and work out how the spring leverage ratios work (the load is not transmitted vertically) and the impact of the (front) ARB.

Andrew
1965 Lotus Elan S2 26/4022 (originally Dutchess Lotus East, PA and NJ Area, USA)
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PostPost by: nmauduit » Thu Jun 24, 2021 9:04 am

661 wrote:I found the TTR 325lbs 8" front springs were too long to get the car to race ride height (610 Kg). The 7" springs worked well but are very close to rattling on full droop.


the use of a helper springs (short weak spring on top of the main one) may be of use when fitting very stiff springs on a car that has a relatively large amplitude
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