Plus 2 suspension

[rgh0]

Hi Rohan,on springs did you ever have a look at the eibach double spring system with a main and tender spring,when you were developing your cars
regards
Paul

Hi Paul
I looked at various progressive spring arrangements but not specifically the Eibach one. In the end I conclude I wanted to stick with the standard Lotus progressive rear spring arrangement ( which was about 30 years ahead of its time). The Aeon rubber spring is a critical part of the rear suspension. People who remove it or replace with a bump stop as the standard Aeon spring does not fit in the smaller diameter springs don't really understand its function

It forms the second element of a progressive spring arrangement at the rear with a soft initial rate from the steel spring and then a firmer and progressively increasing rate from the Aeon rubber spring. For My Elan i space this rubber second stage progressive spring down by 20 mm so it comes into play a little earlier which cures most of the over steer on the limit that Elans suffer from especially on modern tyres. A rear anti roll bar would do a similar function. The later Plus 2 had this 20 mm spacer as standard from Lotus which is where I got the idea from.

I also played with stiffer Aeon springs at one stage ( they come is various lengths and spring rates) but concluded this upped the rate to much when they came into play and made the car to twitchy. I like a race car that is easy to drive as i am not Jim Clarke

Others in Europe run much stiffer set ups than me and it is very much personal taste and skill that dictates what you can do so maybe a stiffer Aeon rubber spring would suit them.

At the front there is not much room to do anything fancy with modern progressive spring designs so just a stiffer roll bar for a road car on modern tyres is all you need I believe and stiffer springs and roll bar if wanting to stiffen it up a little for road or racing.

When Lotus designed the Elan they were the best in the world at suspension design ( maybe they still are) so you change it with lots of thought only where other things such as modern tyres grip level requires it.

cheers
Rohan