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.

Watch Out for Aftermarket Sensors

 Aftermarket sensor are not always assured to work.  We have an Elise in here that was not running properly.  The client sent the car to two different shops including a Lotus Dealer and was unable to get it sorted.  

We got the car and after checking the usual components, Jorge noticed that the Oil Pressure sensor on the VVL looked a bit different.  Upon closer inspection, you can see the orifices are different sizes.  We installed a factory sensor and the car started to behave as expected!

Aftermarket on the left

Oil Pressure Sensors Are NOT Interchangeable!

 We discovered an oil pressure issue on a 2ZZGE-equipped Elise.  It turns out, there are two interchangeable sensors on the engine that will allow the car to start and run.  In other words, they can be screwed in and plugged into harness in either position!  But if they are switched, the car will throw a code when revved into the second cam.  

Other than being different colors and having different numbers printed on the sensors, both oil pressure sensors visually display very similar characteristics and use the same style electrical connection.  

They are boxed in red above

The black Pressure Switch sensor is supposed to be installed in the head and the gray Sending Unit goes into the oil filter housing.  

We found the Toyota part #s as well.  Se below:

Clam Alignment Trick

 Body fitment can be a challenge on a Lotus but there are some tricks you can use to help when you refit your front clam.  This picture shows an easy what to align the clam as you are shimming and tightening it down.  Simply apply the tape and draw lines across it BEFORE you remove the clam.  

Jorge came up with this nifty idea...

Evora GT Clutch, Flywheel & Delay Valve Replacement

 The Evora GT is an amazing sportscar that has true supercar potential.  We've successfully tuned one to 500hp and enhanced it's brakes and handling.  The feel and sound of this car is still quite thrilling and dramatically better than most modern sportscars on offer.  The Evora has one issue that should be considered before purchasing one - it's clutch.  If you are considering one of these cars, make sure to have the clutch operation inspected by someone who knows these cars.

We received an Evora GT from a new owner who bought the car from the East Coast.  Upon delivery, he noticed the clutch did not operate the way he expected.  He immediately sent it to us and we confirmed that the clutch needed replacement.

A clutch replacement is an engine out job which requires a rear clam removal.  We got to work...  

The clutch and flywheel both showed hot spots that caused the performance issues.  

We replaced the parts with factory parts but one key part we replaced was the Clutch Delay Valve with our Evora Clutch Line (Delete Pipe).  We Blogged about this previously: HERE.  

We believe the factory delay valve may have caused the previous owner to slip the clutch in response to the delay they were feeling when driving.  Or they were simply dumping the clutch and doing drag strip launches.  

This is much easier on a GT with the engine out but can still be done on cars with an engine still installed.

We installed our ESWkit as well to smooth out the shifting of the car.

Oil Cooler Delete - Highly Recommended

 Lotus fit two oil coolers to the 2005 Elise.  Oil Temp testing by the community revealed that we have an over cooling problem with our cars.  These cars have significantly more oil capacity thanks to the twin coolers and associated piping.  We firmly believe cold oil is contributing the cam wear that many have experienced.  

Lotus deleted one of the coolers starting in 2006 - unless you have a Sport or Track Pack equipped car.  They used a hard line pipe in place of the oil cooler (as shown above) on the passenger side of the car.  We have been purchasing these lines to delete the extra cooling in our own cars - including our 111RS.

The OE part is no longer available so we decided to create our own using some parts that we have used in other oiling solutions that we offer.  So we stole some bits from our ULTRAliteLINES and HOTplate to create our own oil cooler delete pipe.  We are installing this onto a good clients car.

We now have enough experience to recommend deleting one cooler on all street-only cars and most track cars.  As a result. we will create a part for sale based on this first article soon.