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Elite/Eclat and Excel suspension differences - Ride/Handling/Suspension/Brakes/Wheels/Tyres - The Lotus Forums Jump to content
rjwooll

Elite/Eclat and Excel suspension differences

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I've recently discovered that there may be a big difference between the spring rates fitted to the Elite/Eclat, and those fitted to the Excel.

 

According to the Autocar technical analysis of the Elite published 18/5/74, rates are 105lb/in front and 115lb/in rear. The front spring rate was increased for cars fitted with aircon. This is substantiated by road tests of the time which praised the ride for its comfort, and by my recollection of being told that Lotus suspension design philosophy was soft springs with stiff dampers. This was after being impressed with the ride and handling of an Elan S1 some years ago.

 

I haven't seen any official figures for the Excel but it has been stated by people who know that the rates are 350lb/in front and 250lb/in rear. The suspension geometry of the Excel is different at the rear with inclined spring/damper units which reduces the effective spring rate a bit.

 

Foe what its worth, I really like the soft springs/stiff dampers approach - stiff springs just limit wheel travel and so can be used to hide compromises in suspension geometry.

 

Can anyone cast any further light on this issue? I've only driven an S1 Elite before my modified S2.2, but not an Excel - has anyone driven both and can you comment on differences in ride/handling?

 

I have also asked Lotus cars if they can provide any information.

 

ATB Richard

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I had a 1990 Excel SE for a year or so, and have recently bought an Eclat 2.2.  I'll post my thoughts on comparison once I have driven the Eclat a bit more, but at present its carbs are being refurbed.

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Hi Richard,

 

as you know, I have also both. One has everytime to keep in mind that the state of the cars we are comparing are not in similar conditions. In my case both suspensions have to be overhauled... so seem to be nearly comparable :D But... for example the ARB on the Excel has polybushes and on the Eclat they are completely worn. This will influence the behavior in the same corner right considerably.

 

At the end the Eclat feels good amount softer. Yes. The behavior of the rear is completely different. The rear steers a bit itself into the corner. The Eclat feels also a good amount lighter :) and with that he is quick as the Excel. Where the Excel is more modern, with a bit more cart feeling = less body roll with great cornering speeds the Eclat does this with the same speed but unspectacular. Unspectacular sounds wrong with the more on body roll, but if you begin to realize that this could a huge movement of the body... you are just through the corner. And when you look at the speedo you get slightly shocked that the speed is such high :driving:

 

I think the will be a speed where this effect will shear apart, but still I havent found it (but I am trying ;) ) I think the layout of the Excel will give the driver more confidence in the way he performs. Maybe one get used to it... I dont know yet.

 

For a detailed comparison you have to take also in account the Excel on its own has got 4 different damper and two different spring sets. With the latest spec the MY89 has for sure a slight different behavior than the earlier ones. The Elite/Eclats have had 5 spring sets... So this will be big examination :) But I would love also to read as many comparisons as there are out there :)

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Thanks Don, interesting comments about the comparison and it tends to support the assumption that stiffer springs are fitted to the Excel. Your Eclat behaviour sounds much more to my taste - effortless and almost unbelievable!

 

Richard

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I can provide a conclusion on this issue - the original Lotus Elite spring rates do indeed correspond to those published in the Autocar launch report in 1974 - i.e.:

Front with a/c: 145lb/in (approx free spring length 17.25")
Front without a/c: 105lb/in (approx free spring length 18.25")
Rear: 115lb/in (approx free spring length 15.75")

The Elite/Eclat suspension is clearly longer travel and softer than the Excel setup.

Lotus Cars were unable to provide this information, so thanks to Mike Taylor at Lotusbits for carrying out these tests!

ATB Richard

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Thanks Richard for these values. :)

 

So... I have red Koni-shocks on the rear.They are not old and haven´t got much miles... When I close the trunk, not smashing the boot lid, only gentle closing it with the hand on the lid, the car goes a huge amount down on the rear and bounce a bit. Not like a american cruiser though.... only one time. Is this then a normal behavior caused of these long and soft springs? 

Edited by Don.Hasi

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Hi Don, that sounds normal to me. Shock absorbers can be set up differently for bump and rebound, I believe. The level of bump damping dictates how much resistance is applied to the compression of the suspension (such as when you close the boot lid). The level of rebound damping dictates how quickly the vehicle returns to its normal height. It really depends on how you feel the car handles on the road - if it bottoms easily on undulating roads, you probably need more bump damping. If it feels bouncy, you probably need more rebound damping.

 

ATB Richard

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It is only noticeable when the car stands still. When the car drives it feels smooth and quick all the way. I have just wondered about if this sounds familiar to someone else.

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I always thought that the revised suspension on the Excel was Toyota derived. I've certainly read before that the brakes and diff are Toyota items, but just came across this article from Motor Sport in 1983 which states: "...the rear suspension was modified to incorporate the Esprit's top link and lower wishbone layout in place of the Chapman strut."

 

http://www.motorsportmagazine.com/archive/article/september-1983/60/excellent-lotus-excel

 

Of course they may have used Toyota suspension components to achieve this goal, but it is good to read that the suspension design has proper Lotus heritage.

 

ATB Richard

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