Saturday, March 11, 2017

Front suspension improvements; upgraded brakes


The Delorean’s front suspension is… not ideal…. for a couple of reasons:
1. There is literally no longitudinal constraint of the lower control arm. The only thing keeping the wheel from flexing fore/aft is the sway bar which in other words is having to serve dual purposes: Reduce sway and stabilize the LCA. Not ideal. This design arrangement is a legacy from Colin Chapman; the same concept was used on the Lotus Esprit S1 but was subsequently corrected  on the S2 (or S3) later on. To remedy this, I will:
  • Add two sets of massive stainless steel lower control arm reinforcements from Delorean Europe that will provide triangulation, of course without in any way affecting the suspension from its proper compression/extension as it should.


Added stainless control arms for triangulation

  • Replace the lower control arms with similar, new d:o with the only difference that the new ones are made from thicker gauge metal and are also “boxed” in, i.e. its profile is no longer an inverted U-shape, but a rectangular shape for increased rigidity.
Original LCA above; new and improved below (including new ball joint)
  • Replace all of the rubber bushing in the UCA, LCA and sway-bar with polyurethane d:o. These too come from Delorean Europe. The new PU bushings come with nicely machined stainless spacers and inserts (and have the precision worthy of a Swiss watch):
Polyurethane bushings with stainless hardware (L&R)
2. The stock, front springs do not compress in a straight line! The way the spring is oriented in relation to the movement of the suspension does not allow for a linear compression/decompression; instead it describes somewhat of an arch. The main reason for this flaw being that the lower end of the spring sits (in a “cup”) on top of the lower control arm, which in turn, of course describes a circular pattern about its pivot point as it moves up and down. In addition, it appears that the spring has been interfering with the upper end of the shock tower as the metal is a little mangled there. (this is prevalent on both L&R sides). Likely the result of the fore/aft movement mentioned earlier!
A view of the stock suspension and its imperfect geometries
 
To rectify this, I will install an entirely new spring/shock arrangement supplied by DriveStainless/QA1 where the lower end of the spring is not resting on the lower control arm, but instead rides on the lower end of the shock itself, thus making the spring perfectly concentric with the shock. This design not only provides perfect in-line alignment between the spring and the movement of the suspension: it also enables adjustable ride height and in addition, the shock has adjustable dampening.


Adjustable ride height/ adjustable dampening. Pure perfection from DriveStainless / QA1 

The end result with all of the above improvements will be:
  • increased stability under hard cornering and braking
  • increased stability (less “float) during high speed driving

In addition, I will also be replacing the front brake rotors with vented d:o to reduce the risk of brake fade. I will be using the stock calipers, but spaced apart to accommodate the increased rotor thickness. Some D owners have opted to go with four-piston A/M brakes (such as Wilwood etc.) but that will/may technically introduce a front-to-rear brake bias issue, and without the means of brake bias adjustment I am not willing to go there....

Vented brake rotor. An authentic Delorean upgrade from Delorean Europe.

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