A SERIES EVO L.S.D.

The cases are machined from steel billets, and all components manufactured to exacting specifications from high grade materials.  On the road tests have proven that the bevel gear and plate pack are capable of absorbing 230lh ft of torque in front wheel drive applications.  The cross pins are much more substantial than other types.  Their design combined with the employment of an isolated drive case means that they are not subjected to bending stresses an inherent problem experienced with the Salisbury diff, thereby eliminating cross pin failure.

All parts are checked after each stage of production to ensure consistency, and then finally individually hand built to a predetermined specification.  Instructions detailing ways to change the performance of the unit that can be carried out by the user are enclosed.  Other alterations in specification are essentially trial and error and would require replacing some of the components with differently machined parts.

The finished units small overall size to a bare minimum the modifications required to facilitate fitment to the gearbox.  It accepts all crown wheels for SD application, and can be used with the common Hardy Spicer type output flange or stub shafts for use with pot-joints.

The EVO diff is solely available from Mini Spares Centre ----- Who owned it under the Trannex banner previously.
As are all relevant parts for fitment.

HI-TECH ELECTRONIC TECHNIQUES FOR ‘A’ SERIES

Here at Mini Spares, our product research, development and production program continues unabated.  Particular attention is being paid to the forthcoming problems presented by the deterioration of 4 star fuel quality and ever tightening emission laws.  Seemingly bad news for the performance enthusiast.

Following our recent successful release of the Arden 8-port head (without its previously inherent porosity problems) our minds turned to an alternative fuel supply system to complement the twin side draught or four Amal set up usually used.  Bearing in mind the aforementioned fuel quality and emission problems we embarked on a programme to develop an electronic fuel injection system.  The beauty of electronically controlled fuel injection is that performance can be greatly enhanced with very tightly controlled fuelling at any given rpm/load/temperature combination and can effectively ‘tame’ fairly wild camshafts.  Economy also has a hand up due to less fuel wastage.  The problem was where to start! 

There are a number of ‘bolt-on’ fuel injection kits on the market, but price is prohibitive and the performance is really aimed at much larger engines.  Programming the ECU (Electronic Control Unit) would also prove a trial.  Many ECU’s used have too many functions that are not required for a basic set up, making them relatively expensive to start with.  Further investigations and recommendations lead us to team up with a prominent engine development man heavily involved with cars used in current modern motorsport (including the BTCC).

Obviously the idea is to produce an effective package at a realistic price.  This meant minimising production costs, leaving out unnecessary and unrequired electronic variables.  A basic package using a potentiometer (indicates throttle angle), air temperature sensor, humidity sensor, and engine temperature sensor combines with a specifically designed ECU to control the injection system, and our recently developed electronically programmable ignition package.  Much time has been spent on researching electronic componentry that is both totally reliable yet sensibly priced (the crank sensor from Lucas would cost £150!) and methods of manufacture to ensure high quality and reliability.  Considering a Weber Alpha kit would cost over £1530.00, we are sure we can produce the complete conversion kit for nearly half that price, we envisage £825.00.

The conversion kit will comprise a plenum chamber, throttle body (optional sizes dependant on application),injectors fuel rail, pressure regulator, F.I. ECU, loom, crank pick-up, shutter disc, all sensors, potentiometer, ignition ECU, and all required fuel lines, etc. for installation to the 8 port head.

This would include, as previously mentioned, our recently developed programmable electronic ignition package. It has become evident that with the forthcoming vehicle emissions legislation and the poor fuels situation for racers, ignition timing needs to be absolutely precise throughout the engine’s operating rp range.  This is not only to ensure optimum combustion efficiency, but also to produce maximum power outputs without causing piston failure.

The ‘A’ series is renowned for its peculiar ignition requirements.  Although there are a number of proprietary modified distributors available, in many instances they fall far short of what is required by any given engine.  Every engine needs a different ignition curve, so it is obvious that a small range of modified distributors cannot possibly cover the innumerable combinations of engine specifications used.  An educated guess however, by one of the more experienced ‘A’ series exponents, is that it is going to be a great deal better than any old dizzy.

As the electronic kit is totally programmable it can be set to the engine’s EXACT requirements.  Even if the timing needs to be RETARTED at any given point;  a feature not possible with a conventional distributor as they are totally linear.  Other obvious ignition inaccuracies when using a distributor are caused by points bounce, bent or worn spindle, scatter caused by cam drive train lash – none of which occur with the electronic unit.  Results are soon to be available giving performance differences between the conventional and electronic ignition systems following extensive dyno and road tests with details of availability and price.

Following the completion of this kit, we are applying the experience gained to produce an effective duel injection kit for the 5 port head for release in the not too distant future.

READ PART ONE OF THIS EVO L.S.D ARTICLE

READ EVO ARTICLE

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