My set of nitrons are in!  The set consists of: - 4 adjustable shocks
- 4 springs
- 4 adjusterrings
- 1 ABS bracket
- fitting materials
 Before I ordered the kit, I did a lot of calculation. Arno has been
driving around with a set of nitrons for a while and recently changed
the springs for stronger version. The result is that you can set the
shock to a lower setting without losing control. I wanted to achieve the same effect, but the weight of the Speedster is
different than that of the Elise. Below you find a table with some
vaules. All spring values are in lbs/inch (pounds per inch). The last
column shows the relative spring strenght between the front and back. Car Spring brand Front Rear Relative strength front Relative strenght rear
Lotus Elise S2 (standard) Eibach 228 285 44% 56%
Lotus Elise S2 (nitron) Nitron 325 400 45% 55%
Lotus Elise S2 (Arno) Eibach 400 500 44% 56%
Speedser (standard) Eibach 234 268 47% 53%
Speedster (nitron) Nitron 375 450 45% 55%
Speedster (Mark) Nitron 450 550 45% 55% In the end I went for the last line in the table, 450 front, 550 rear.
This way I compensate for the higher waeight of the car and hopefully
reduce a bit of the understeer with a lower spring strength in front. Before fitting the springs and dampers, I put a layer of tectyl on the
springs for extra protection.  After all the prep work it was time to jack up the car and remove the
wheels.  The left ront needs the upper damper bracket to be replaced. It's the
one the ABS unit it fixed to.  After removing the old bracket and placing it next to the new one, you
can see it is a bit wider, allowing for the slightly wider damper.  After that, the new bracket can be fitted.  After placing the bracket the new dampers can be placed. On the picture
below you can clearly see the difference between the old and the new
dampers.  Before placing the dampers, we replaced the bolts in the hub. Standard
8.8 bolts are used, and there are some cases (including Arno's Elise)
where they bend. We replaced them by 12.9 bolts, front and rear. This is
little bit too hard, but the 10.9 are very hard to find. To compensate
we used a little higher torque setting, 60Nm in stead of 45Nm.  Before placing the dampers, we cleaned the wishbones and also put some
tectyl on them for protection. After cleaning the new dampers were fitted and the bolts torqued up to
45Nm.
 After rotation the car to do the other side, you could clearly see that
the rideheight of the car will be lower. This picture is without any
preload on the springs. Later on the car will be a bit higher.  The other side is a bit easier, because the bracket doesn't need to be
replaced. After all the dampers were replace we measured the ride height (ofcourse
with 75KG's in each chair) and changed the preload on the springs. With
about 20mm of preload (measured on the thread on the damper) the
rideheight was about 120mm front and 120mm rear. The ride height wasn't
adjusted perfectly, as it needs to be done again anyway when the new
wheels come in. The nitrons were set to 18 clicks from hard front and 16 clicks from
hard at the rear. The car now looks like this:  The car is very drivable like this. Because the dampers are set
relatively soft (because of the harder springs) the car is quite
comfortable on a bad road. And speedbumps are not a major issue (you
still have to look out for them) because the car doesn't dive into its
suspension that much. |