Lotus Esprit V8/S4S Adjustable Rear Shocks

If you have been reading, and perhaps implementing some performance modifications as documented on this Web site, one of the items you may have considered a priority was removing the stock exhaust assembly. Once replaced with the straight pipes, (please refer to the exhaust replacement article on this Web site) you may notice that the rear of the car is a little higher off the ground than before. The most noticeable is the gap between the rear wheels and the wheel arches.

To correct this, and perhaps bring the rear of the car down a tad lower, (We lowered ours about 1.5" from stock) you will need to perform some suspension mods. We replaced the stock shocks with an after market double adjustable gas shock made by SPAX of Germany and the UK. They are excellent quality shocks with a height adjuster, and a "firmness" or "ride" adjuster. The nice thing about the SPAX shocks is they can accommodate the odd 3" ID Lotus stock springs. The kit we acquired comes with a 2.25" to 3" adapter plate.For the first iteration of this mod on our car, all we replaced was the shocks and re-installed the stock springs. This dropped the rear the 1 5" we initially desired without compromising handling.

We found that once removed, the old mechanics would accept a 2.25" after market spring if we wanted to upgrade from the stock springs. Perhaps later we will invest in a pair of Eibach springs that are a little shorter, but not at this time. The top spring seat on the Lotus Esprit has a 2.25" seat, and most after market shocks are designed for 2.25" springs.

Some Interesting Technical Information

Important specifications of springs are their size and spring rate. Here are some specifications for the Lotus Esprit V8.  This is provided just in case you want to upgrade to Eibach springs or your favorite spring provider.

Esprit V8 - (US Version)

Front - 43 Newtons Per Millimeter = 245.53 Pounds per Inch
Rear -  48 Newtons Per Millimeter = 294.08 Pounds per Inch

Esprit GT350 V8 (US Version)

Front - 61 Newtons Per Millimeter = 348.31 Pounds per Inch
Rear -  58 Newtons Per Millimeter = 331.18 Pounds per Inch

Removing The Lotus Stock Shocks

This is actually quite easy. You should use a coil spring compressor, and be VERY careful. We found the rears do not really need a coil spring compressor, so we will describe the procedure without one. If in doubt please use a spring compressor, and take all the precautions recommended by the manufacturer of the spring compressor you select to use.  We actually purchased one from Harbor Freight that did the job well, on the first spring we removed.

This is a very easy procedure. You can refer to the Lotus Esprit V8 1998 onwards, workshop manual for details. We proceeded as follows:

• First jack up the car, and place on axle stands. Put the stands on the chassis of the car, NOT the lower suspension rods.
• Remove the road wheel.
• Remove one of the top shock retaining nuts. (There are 2, one is a lock nut)
• Remove the lower shock absorber retaining nylock nut and washers.
• Using a hard wood dowel, tap the bolt out of the lower shock mount until it just clears the shock mount. Support the shock it will drop about .5"
• Remove the other nut from the top of the shock mount.
• The shock will now slide out. The spring will probably stay in place as there is a rubber damper at the top and the springs on ours were stuck to it.

That is it for removal, simple wasn't it?

Installing The SPAX Double Adjustable Shocks

This section assumes you are at the end of the shock removal section above.

• Remove the new shocks from their packing, remove both lock nuts, the first rubber mount and the metal support plate from the top of the shaft.
• Adjust the lower shock adjuster to it's lowest position. (So the lower adjuster ring is just over the first thread).
• Install the lower 2.25" to 3" ID spring adapter. (This comes with the shock)
• Do not remove the lower Lotus OEM spring spacer at this point, unless you want to lower the rear more than 1 - 1.5".
• Insert the new shock shaft into the upper shock mount, through the stock 3" ID spring, If you removed the spring, make sure the top rubber mount is in place. Install the top rubber mount and support plate, and secure the first lock nut onto the shaft.
• Tighten the first lock nut until you feel a slight resistance (This is the end of the thread on the shaft) DO NOT OVER TIGHTEN.
• Install the second lock nut and, while holding the lower nut, tighten it, so it locks into place. DO NOT OVERTIGHTEN
• Using your hand and a little strength, support the lower shock mount in the area of the mounting bolt, and push the both through. This requires you support the shock, and lift it against the spring about 0.5". It is not hard. Once located, tap the bolt through while supporting the shock mount against it's mounting. DO NOT FORGET TO REPLACE THE WASHERS, the largest is before the nylock nut.
• Install the nylock nut and torque to 40 - 45 ft/lb.
• Adjust the dampening adjustment screw in, 14 adjustment notches, (NO MORE, if you overshoot or loose count reverse the adjustment back to the stop and start again) then back it off 3 adjustment notches for a total of 11 adjustment notches from the fist sign of resistance.
• Lower the car, roll it back and forth until the ride height stabilizes.
• Measure from the ground to the lower suspension mounting and make sure the left and right are the same height. This adjustment will vary from car to car. MAKE SURE YOU ARE ON A FLAT EVEN SURFACE.
• MAKE VERY SURE YOUR ROAD WHEELS DO NOT FOUL THE TOP OF THE WHEEL ARCHES.

That is pretty much it. You will need to raise the wheel on the side you are adjusting the height of the shocks EVERY TIME you perform the adjustment and roll the car back and forth to stabilize it. If you want it lower, you can remove the lower stock spring spacer. This will give you an extra 0.5" of drop. Any lower you will have to go to a shorter spring, but that is another story. Good Luck.

After a Few Test Drives

Not bad at all! We adjusted ours, so the rears looked right in line with the front clearances. (between the road wheels and the wheel arches) It was really simple to do. The final adjustment came to 6.375" or 159mm off the ground to the center of the lower mounting bolt(s). This implies we will not have to remove the stock spring spacer(s). As mentioned earlier, you could go lower, but we do not recommend it. This would involve spacer removal and/or shorter springs. With this minor adjustment there is no need for any alignment. All is fine and dandy.

We hope you find this article interesting. The SPAX Rear Shock Part Number is:    G354  you will need two of them.

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