Lotus Marques CV drive shaft kit. A direct replacement for Lotus Elan S1, S2, S3, S4 and +2.
Why upgrade from rubber doughnuts?
Originally we intended to explain just how good a CV drive-shaft conversion really is and how it transforms the drive-train on any Lotus Elan or Elan +2.
However, we decided it would be more relevant if one of our long term customers Dean Ryan shared his personal experience below.
When I was racing my Élan back in the mid eighties I witnessed the damage a failed doh nut caused a plus two Élan.
It nearly destroyed the car’s body work & the drive shaft & upright. I suspect the damage was near the $10,000 mark.
The doughnuts I was using were showing signs of stress cracks so the decision was taken to look at alternative.
I searched the usual suspects in the UK & the offerings were OK but heavy plus an assortment of cut down remanufactured VW sliding spline cast offs.
A club member put me in touch with Lotus Marques in Melbourne.
Various discussions were had with Steve regarding the design and construction before I decided to purchase a set.
Instruction/tips regarding the installation were all provided.
The parts were all carefully plated & the end result was a vast improvement over the doughnuts.
The original use of Doughnuts was to reduce shock etc but for normal road use & some track days have not revealed any concerns you might have in using them.
I would highly recommend the Lotus Marques CV drive-shaft conversion to any Elan owner who is considering the change.
Dean Ryan - March 2012
Your Lotus Elan deserves the best product that is guaranteed to deliver many years of reliable driving pleasure.
Once again, Lotus Marques delivers extra value by making a number subtle improvements to enhance a world class product.
In summary, the latest improvements include -
* Fully CNC machined adapter plates, including all chamfers (no more hand finished plates)
* Fully CNC machined radial lightening slots (further reduction in un-sprung weight)
* Fully CNC machined threaded holes (improved fastener location accuracy)
* Fully CNC machined high tensile studs (captive bolts eliminated to simplify installation)
Lotus Marques understands engineering is a precise discipline and requires the appropriate resources to manufacture unique world class products.
No single individual has been responsible for producing the latest generation of the light weight CV conversion kit
Instead a team of qualified and talented engineers were involved in producing the latest generation of Lotus Elan CV drive-shaft kits.
Terry Duell - A suspension design and ride consulting engineer carried out a comprehensive safety investigation to determine the effects of replacing the original rubber drive-shaft couplings with CV joints.
This report was prepared in May 2004 exclusively for Lotus Marques (previously The Elan Factory) and a copy entitled "Lotus Elan Rear Suspension - The Effect of Half-shaft Rubber Couplings" is available at the following URL http://members.iinet.net.au/~tduell/lib.html
Gary Woodward - Ex Formula 1 engineer (Williams and BAR/Honda) provided the necessary design input into reducing component weight and improving the CV joint operation by detailing the internal components.
Steve Taylor - Ex weapon systems engineer (UK Department of Defence, Fort Halstead) and now business owner Lotus Marques, provided a comprehensive suspension analysis and comparison across various rear drive-train options.
A copy of the Lotus Elan rear suspension and drive-train analysis may be viewed on the Lotus marques web site.
A close look inside
What is important for our customers to understand, there are no compromises in terms of components or machining.
Lotus Marques has established a reputation for the design and manufacture of high quality components.
Unlike our competitors, Lotus Marques puts customer safety before profits.
The first step is to dismantle the brand new GKN CV joint and carry out a thorough inspection.
Next step is to machine the CV joint external casing to reduce weight without sacrificing strength.
Each CV joint is detailed to remove undesirable manufacturing marks so the movement is silky smooth.
With CAD design and CNC machining its possible to produce a much lighter and stronger spacer plate.
The new light weight adapter plates are then populated with CNC machined high tensile studs and grease nipples.
New fully CNC machined axles awaiting a coat of epoxy paint prior to final assembly.
We could show here, a fully assembled drive-shaft in our lathe with a significant off-set or axle angle established between two CV joints.
We choose not to do this exercise as it demonstrates a lack of understanding of the real-world environment as there is no vertical dynamic load.
Once again Lotus Marques demonstrates it has a world class product that delivers exceptional value for money.
It is interesting to note, whilst the design and quality of Lotus Elan CV drive-shaft has been significantly improved, the price has not increased.
For peace of mind, Lotus Marques offers a two year limited warranty on this product.
This warranty is made possible by ensuring the following design and manufacturing checks are carried out.
Product update - March 2013
Lotus Marques has redesigned the adapter plate to produce beneficial un-sprung weight saving of 10%.
This has been achieved through careful CAD design so as not compromise the strength of the CV drive-shaft adapter plate.
Lotus Marques continues to demonstrate its commitment to product improvement without increasing costs and thereby delivering exceptional value for money.
Product update - February 2014
With additional subtle improvements and changes in CNC machining techniques, Lotus Marques has achieved a further weight reduction of 200grams per axle assembly.
Current axle assembly weight including all fasteners for Lotus Elan is only 4.9Kgs.
Current axle assembly weight including all fasteners for Lotus Elan +2 is only 5.1Kgs.
Product update - April 2014
Currently under development is an improved version of the CV conversion for the Lotus Elan which is intended to tip the scales at just 4.5Kgs.
This version will be supplied with aero-space fasteners manufactured by ARP and have a significantly extended warranty.
If you are contemplating purchasing a CV drive-shaft conversion, then make sure you are not purchasing an over-weight product.
Please contact Lotus Marques for current pricing as the CV joints are imported from Germany and are subject to currency exchange rate fluctuations.
Shipping from Australia to UK, USA, New Zealand, anywhere worldwide!
Contact Lotus Marques now for postal or courier shipping costs.
What our customers are saying
I've now fitted and tried out the CV jointed rear axle set that you supplied me to replace the original "Doughnut" type fitted to my 1971 Elan +2.
The kit arrived here well packaged and the finish visually was top class.
Fitting them up was no problem at all and it took me approximately 3 hours.
The only tool I needed to borrow was a 5/8" open end,long series spanner,to tighten up the 12 Nylock nuts.
The " free play travel" on the CVs at the bottom of the suspension travel was exactly as you specified with out any adjustments.
To drive the car now is a lot different than before the conversion ..........NO waiting for the wind up on acceleration.
The action of the rear suspension on hard cornering is smooth and seems superior to the original set up.
The thought of the CV conversion being too rigid ,on the differential is just a myth-- remember Colin Chapman developed the IRS suspension using the "live Ford rear axle" with solid axles out to drum brakes !!!
I would thoroughly recommend your conversion kit to any person considering spending "Dollars" on their pride and joy as money well spent with regards to PERFORMANCE - RELIABILITY - SAFETY and value for money.
Leicester Harris, New Zealand - March 2014
About the author
Steve Taylor: is the business owner of Lotus Marques who has a multidiscipline background. This includes 12 years engineering experience gained whilst working on weapon systems design and development for UK Department of Defence. He has also worked for 7 years in a cutting-edge American super-computer company Gould CSD as the UK southern region support manager. During this time he developed a passion for Lotus Cars and motor racing at Brands Hatch Racing School. Emigrating from the UK to Australia in 1987, where in 1992 Lotus Marques commenced trading as a specialist parts supplier. The business offers log-book servicing and repairs as well as designing and manufacturing high quality components to support Lotus owners world-wide.
Those who cannot innovate can only imitate!
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