Exterior Connector Failure from Corrosion

 

We had to repair an HVAC unit on an Elise that was not operating reliably.  It turns out that the wiring had failed.  More specifically, a connector failed due to corrosion.  Of course, it was an intermittent failure that had us stumped for a bit!  Note how the pin has fallen out of the connector in the bottom image.  Sometimes it has continuity and other times it did not.

The front of these cars are exposed to water and weather.  Typically a manufacturer will use connectors that are sealed and designed for exterior use.  In this case, an older style connector was employed that allows water ingress.  These were commonly used in the 80s and started to get obsoleted in the 90s as connector tech improved.  

We repaired the connector and added some dielectric grease to better protect it from moisture.  Though this is not the best solution, it is one that you might consider if you are trying to keep your car original - as this client requested.

One of our common services, for the Elise/Exige, is a HVAC resistor pack update.  We may need to add a connector update service as well!  For clients that want a sealed solution, we can offer that easily.

ECU Communication Failure via OBDII & Repair

We've experienced some communication issues with certain ECUs over the years.  Jorge noticed a microchip on a T4 (2005 model year) that appeared burned.  He identified this was the chip that manages communication for the ECU via the OBDII port.  

As many of you know, the On Board Diagnostic (OBD) port is how we can read codes and read data from the T4 computer.  The rest of the ECU may be working fine so it will continue to run your car.  The problem lies when you attempt to read and clear an engine code that might be set on your car.

We were able to successfully replace the burned chip and restore the ECU to full operation.  We have a local friend who builds electronics for the defense industry with the know-how and equipment.  We recruited him to assist.  

These ECUs are no longer available new so keep the existing ones operational will be important as we attempt to keep these cars on the road for as long as possible!

Suspension Set Up Tips

I came across a nice Elise/Exige suspension guide that we had from Nitron.  I've updated some of the information to be jive with our current thinking on set-up.  See the edited guide below:

1. Setting up ride height 

1a. Lower is better…to a point.   

By lowering the ride height of the car, you lower the car’s center of mass (weight). As such, when you go round a corner, there is less tendency to ‘tip over’ like a tall bus or truck would want to.  This reduction in rolling force means that the tires are more evenly loaded, so you ultimately get more grip.  Less roll has many other good side effects including the following: more ability to apply power, better wheel geometry constraints, more stable underbody gap for aero work (if relevant), and it better feel!  If you go too low, however, the roll centre geometry will start to work against you.  

1b. Ride height suggestions 

130mm in the front and 135 in the rear is a good starting point for most street/track cars. As a comparison, the Lotus Sport Suspension has a 140mm ride height.  If road conditions are not a concern, then 135 / 140 can also be a good starting point.  We suggest going no lower than 118mm front and 125mm rear - unless you are running our raceUPRIGHTs.  There should always be a 5-10mm rake in the chassis front to back.  

1c. Do your springs rattle? 

When you set a car down on its springs, they squash a given amount.  A soft spring will squash a lot, and a hard spring will only squash a little.  We call this ‘sag’.  No matter what spring rate you fit, a car will always squash the spring to a given loaded position, and this is defined by the load you are pushing down onto the spring.  A hard spring will squash less than a soft spring, so fitting harder springs will raise the car’s ride height up and up as you go harder and harder, until you reach the point where the car would hardly sag at all if you fitted extremely hard springs.  So as you fit harder springs, you wind the spring platforms on the shocks to lower the car down again.  The harder the springs, the more you have to unwind the spring ‘pre-load’, to get the same ride height.  When the spring starts to rattle around, then you have no pre-load at all.   

If you want the car lowered and want to run very stiff springs, you either run them rattling around (which we used to do all the time on racing cars until recently), shorten the shock’s piston rod length, or fit helper springs.  

Helper springs are used in addition to main springs to stop any rattling around.  These springs are much softer than the main springs and usually squash flat when the car is sat on the ground, but extend when the car is raised up and so stop any rattling.  They also help by continuing to apply a load down on the tire when the shock extends past the point when the main spring is fully extended.   

1d. Nitron Helper Springs for the Elise/Exige

Nitron only stocks one size of helper for the Lotus: these are 2” long and 150 lbs rate.  However, this means that sometimes when you add the length of the helper spring onto the main spring, the total spring length can be too long for the shock body length.  This will not be a problem on the back of your car, but could be on the front if you want to go very low (below recommended).  

If you want to run a lower ride height, please contact us.

2. Setting up compression and rebound 

2a. Nitron Sport - single adjustable 

Nitron has pre-set recommended compression/rebound settings on your shocks.  The dial should be set to 10 from full stiff.  This is only a recommendation.  Personal preference will dictate where you ultimately set your suspension. 

• Always count clicks from the full stiff setting. 

Your adjustable suspension also allows you to “dial out” under/over-steer that can vary based on tire and other suspension set-up conditions.   

Too much over-steer:  

• loosen the rear dial a couple of clicks, OR tighten the front a couple of clicks.  

Too much under-steer:  

• loosen the front dial a couple of clicks, OR tighten the rear a couple of clicks.   

Always make your suspension adjustments in small steps.  Making a large change in compression/rebound setting can dramatically change the handling dynamics of your car.  We suggest no more than 2 clicks at a time.

2b. Nitron Track - double adjustable 

Nitron has pre-set compression and rebound settings on your shock.  Rebound should be set to 9 clicks from full stiff. Compression should be set to 7 clicks from full stiff.  These are only recommendations.  

Personal preference will dictate where you ultimately set your suspension.  As a general rule of thumb, always set rebound less stiff than compression in order to maximize tire grip.  Grip is most sensitive to rebound dampening, not compression. If you are having trouble with grip, try loosening rebound. 

• Always count clicks from the full stiff setting when adjusting either compression or rebound. 

Your adjustable suspension also allows you to “dial out” under/over-steer that can vary based on tire and other suspension set-up conditions: 

Too much over-steer:  

• loosen the compression/rebound on the rear a couple of clicks, OR tighten the front a couple of clicks.  

Too much under-steer:  

• loosen the compression/rebound on the front a couple of clicks, OR tighten the rear a couple of clicks.   

Always make your suspension adjustments in small steps.  Making a large change in compression or rebound setting can dramatically change the handling dynamics of your car.  We suggest no more than 2 clicks at a time.