Emira Harnessbar

Driving a Lotus on track is something that is a joy. But for some of us, a harness to hold us in the seat, becomes an important upgrade to really feel in control.  But safety drives our designs and we strive to produce products that not only work properly but also meet our clients needs.

We have begun designing a new harness bar for the Emira.  Our goal is to create one that:

1. Safe
2. Will be easy to fit
3. No modifications to the car
4. Preserve rear shelf space
5. Light

We have been designing proper harness bars since 2004 for Lotus cars. We were the first to offer a solution for the S2 Elise/Exige in the US.

We created one for the S1 Evora and have created them for other cars like the Alfa 4C.

We understand the safety requirements for this type of product as we work closely with Schroth USA owner, Joe Marko. Joe has guided us over the years to advise us of the latest safety practices. This helps when we are unable to crash test our products!  Joe's advice caused us to make improvements to our first two Elise bars.

We all understand that anything less than a full cage, 6pt harnesses and race seat is a compromise but if it is done well, a safe solution can be created. We know most weekend warriors need a solution that still allows them to enjoy their cars on the street.

Our bar will be quite innovative and easier to fit. Ours will be safe but also light and bolt-in with NO modifications needed. Our bar will offer more shelf space behind the seats than other options.

Here is a picture of the first prototype - this is far from the final design but gave us what we needed to further flesh out our concepts.

ABS Block Delete for S2 Elise and Exige

 Some of you know that we are working on a simple solution to delete the ABS on the Elise/Exige.  The stock ABS comes off a Minivan from the 90s and is not a great performer.  'Black Ice" mode is a common issue for aggressive drivers - especially in bumpy conditions.

We have been working with Girodisc on an idea that would delete the ABS system and replace it with a simple block that would route the fluid to the front and rear circuits via a bias adjuster.  This would allow the driver to adjust the bias to his liking. 

We received the ABS Delete Block (need a better name!) to install.  It is on our ArtCar2 and has seen some quick street testing around our shop.  The block originally came with the bias adjuster connected to it but we decided to install a remote bias adjuster so we could place it in the cabin within reach of a driver.  The servo remains in the system but you lose the speedo.  This car runs the AiM MX2E so we are using the GPS antennae for speed.

The install is slick and I'm looking forward to getting it to the track to test.

Emira Collision: Part 1

The Lotus Emira has been in the US for just over a year now.  A crashed car has made it's way into our shop.  This Blog will detail our progress on this repair.

The insurance company wanted to total the car but the client was quite adamant that the car be saved if possible.  He is a friend/client of ours so we agreed to take a look at the car.  

The car would start so we unloaded it from the flatbed tow truck.  It appeared to drive straight as well - all good signs.  Insurance claims are not a fast or easy process when a car is as low volume as the Emira.  We worked with this insurance company and after a series of calls and meetings at our shop, prepared an exploratory estimate.  We needed to disassemble the rear of the car to determine if the powertrain suffered any damage and confirm other critical areas.

energy absorption saves passengers!

Often times in a collision, damage will propagate to areas that were not in the immediate area of destruction.  In fact, sometimes it is better to simply replace certain parts as they may have hidden damage.  We took the rear of the car apart after getting the A-OK.

The Emira is built like the Evora which runs a similar architecture as the Elise/Exige.  All of these cars feature an extruded aluminum main chassis that feature subframes bolted or glued to the front and rear.  The Emira has a rear subframe that bolts to the main Al chassis tub.  This steel subframe supports the powertrain and is designed to be a crumple zone that can absorb energy in a crash - as it successfully did here.

We were very concerned that the powertrain mounts were damaged.  Fortunately, they appeared to be undamaged.  The Al subframe absorbed the damage.  None of the wheels/brakes/suspension parts were affected.  The side airbags did deploy so will need to be replaced.  But overall the car seems like it can be saved so we prepared a more detailed estimate.

rear mount is intact

This car was designed with collision repair in mind - more so that previous models.  The rear of the car is no longer one large clam.  It is comprised of smaller parts that make replacement, especially for minor issues, and easier proposition.  

we should be able to save the rear glass

The biggest concern is getting parts for this car.  We have placed our order with LotusPartsOnline and are awaiting notice of shipments.  Fingers crossed that we will not be waiting too long.  Fortunately, the Emira is still in production so new parts will be available.

Weight Savings Priority on a Lotus Elise or Exige

 

1691lbs is incredible but not realistic for a street car

Over the years we have developed lighter parts, like our wheels and brakes and put them to use on our cars.  We have not created a road map for people looking to lighten their cars.  The list below is a list that could be used and is in priority - per our experience for somewhat street friendly cars.

1. Unsprung weight savings
• Brakes - ULTRAdisc
• Wheels - Monolite II
• Dampers - Nitron or Racetech
• Uprights - streetUPRIGHTs - coming soon
2. Additional weight savings
• Exhaust: Muffler/Cat/Header
• Seats: ReVerie still make the lightest
• Rear panel removal for above diffuser muffler
• CF rear diffuser
• AC removal
• Stereo removal
• Sound deadening
• CF roof or no roof
• Lighter battery
• Front turn signal delete
• Airbag removal
• Side view mirrors - raceVIEW
• Oil Cooler delete
3. Performance
• Ultimate shiftR package
• Mountune engine
• Al radiator

This became our ArtCar2

This was an extreme build: 111RS Spyder

I think removing 100-150lbs is possible on a street car.  This is hard to do ad requires removal of extras like the AC system and Stereo.  But when you replace existing parts with lighter versions, like wheels or brake rotors, you can start to experience what Lotus is truly about - performance through lightweight.

Lotus Emira Nitron Front Axle Lift

 We've completed a Nitron FAL (Front Axle Lift) installation on an Emira.  It is a great way to get an additional 30mm of clearance.  The Kit can be added to the Nitron Emira dampers.  It comes with all the required pump, wiring and electronic modules to manage it.

The installation is fairly straight forward but should be done by a competent shop.  Wiring and plumbing must be run safely with this kit.

We were able to realize a 30mm lift with the car.  This is plenty of clearance for many road obstacles like speed bumps and steep driveways.

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