Lotus started of with "cylindrical" type springs (with the red koni
dampers). After complaints from customers about the springs rattling
against (actually touching) the dampers, Lotus changed the springs to
"barrel" shaped springs. Due to the shape, the springs did not touch the
dampers any more (change point # W3580). The same dampers were used with
the later springs, but the securing clip on the damper is in a different
position because the later springs are a bit longer. Lotus sport
suspension has again different springs and different (yellow) dampers.
Almost all the aftermarket ones adjust for height, but consensus
seems to be that if car is dropped by more than 25mms then speed bumps
etc start to become real problems. Most also have some adjustment of
damping rates.
Good suspension units is not a cheap exercise, and if you upgrade the
suspension you should also budget to uprade the Anti Roll Bar at the
same time. Every time you change the ride hight you (officially) have to
adjust the geomerty of the suspension. The adjustment of the damping
rate is nice for road or track.
The Lotus Sport set up is a fair deal firmer than standard but
actually more comfortable as it doesn't crash and bang about like the
standard kit which is a bit on the soft side IMHO. The kit includes the
brackets to lower the steering rack so that you don't get bumpsteer. No
rose joints so quite easy to maintain and reasonably quiet. . The ride
height is adjustabble, but you are stuck with the factory settings for
the dampers.
Raceline have developed their own adjustable shocks and springs
specifically for the Elise, working with a small British outfit called
Nitron The kit allows adjustment of the ride height as well as damper
rates: http://www.raceline.co.uk/
Simon S
Posted 23 October 2001 at 18:04:01 UK time
I think
that some basic stuff needs to be covered first:
1) Just because you run a lower ride height does not necessarily
mean that you will ground out more compared to the std setup, if you
run it 20mm lower with ~30% stiffer springs, it will take the same
load to achieve the same reduction is height.
The other bit to remember is that is what the bump valveing of a
damper is for, to limit the speed of the wheel rising into the arch.
2) ride quality (in terms of how stiff the car feels) is 90% to do
with the dampers, not the springs, don't be afraid of what seem like
really stiff springs.
3) The LSS is only 'adjustable' in that the spring platforms can be
adjusted, this does not make them 'adjustable dampers' all it means is
that you have some ability to corner weight and limited ability to
alter ride height.
Of the after-market ones, they basically fall into 3 types:
1) Single way adjustable -
These have one adjuster for either rebound only or bump &
rebound, the latter being at a fixed ratio (normally 3:1 for road
cars).
They will have usually anywhere from 8 to 30 'clicks' from one
extreme to the other, thus to set them you count the clicks from one
end.
If you are looking at these sort they are usually relatively cheap,
but vary in quality a lot, better ones are re-buildable (nothing lasts
for ever and a re-build is way cheaper then replacement).
I personally am not a great fan of SPAX, they are really cheaply
made, Leda are OK but I am aware of seal problems, Nitron ones look
good, but I have no personal experience of them.
As I said earlier, the default ratio for this is usually 3:1, for
the Elise, I would suggest something more like 2.2:1, this seems to be
more balanced for road/track use.
2) 2-way adjustable -
These have separate adjustments for bump and re-bound. Dampers like
these are getting to the serious end of the market and are NOT cheap,
what you do get though is the ability to independently tune the
dampers to the car/spring combination for all circumstances.
Realistically, you are NOT going to get these for road and track
day use, they will take you a year to learn how to use them, and
another to set them up!
Lotus sell Dynamics (as used on the LS-1), these are just stupid
money, and whist there is nothing wrong with them, they do not justify
the sort of price tag asked. Koni make very acceptable ones (I use
these) as do Leda, Ohlins, etc, etc. They sort of go from £1,200 to
£4,000 a set.
3) ¾-way adjustable -
Now, this is where we get onto sill stuff. These have two bump
adjustments and 2 rebound adjustments (1 with 3 ways!). The difference
between the two is one is called fast the other slow, what this means
is that if the wheel is trying to rise because of a bump in the road,
the slow valve will control the damping, if however, instead of a bump
it's a kerb, the force applied to the damper will be much greater, so
the fast valve would also come into play along
with the slow
valve.
This is all well and good with mega-bucks touring cars etc. that
are designed to go kerb-hopping, but with a light car like the Elise,
it's almost totally wasted, aside the need for £10,000 worth of
suspension data logging and M. Shumie's understanding of what it's
trying to tell you. These can cost from £3,000-£20,000 a set.
Getting back to what Dot asked for, I would strongly suggest
something like the Leda/Nitron set with 350/450 (front/rear) springs
and 2.5:1 bump/rebound ratio and an up-rated ARB, this should cost you
well under the LSS kit including having it fitted.
As for ride high, if you have a particular problem with grounding
the car now, then with the above spring rates, 110/120 should be no
worse (and probably better) than what you have now.
Whichever route you go down, you will need to have the geometry
changed to match the dampers/springs and take into account what tyres
and use you want out of the car.
