RUNNING in the Improved Series Category, ID Citroens have won outright the Monte Carlo and Tulip Rallies, as well as being the make used by last year’s European Rally Champion. It was, therefore, with particular interest that the loan of a modified ID was accepted from Connaught Engineering- a firm whose own name was famous in Grand Prix racing not many years ago. It had been obvious when the ID was first tested by The Autocar that further power and improved acceleration would do much to complement the comfortable ride and effortless cruising of this model. Modifications carried out on the car are to Connaught’s own design, and they market it as their II A Conversion. Changes include the fitting of a DS cylinder head of the eight-port type, but with the compression ratio raised from 7-5 to 8-5 to 1. Higher-rate valve springs are also used, and an inlet manifold of Connaught design. Inlet and exhaust ports are cleaned up and matched to their manifolds - the exhaust ones being enlarged slightly. A DS four-coil ignition system is fitted, and an l.t. distributor. A water thermometer is supplied, and the whole conversion costs £156 10s, which includes fitting charges; Connaught need a car for ten days to complete the work. On the car loaned for test a brake servo conversion had been added; this unit is manufactured by the American concern, Midland High Power Servo Unit, and a price of £39 is quoted for supplying and fitting it. Four days are required for the work.

Under bonnet scene with the Connaught conversion

At slower speeds it is doubtful whether the average owner would be able to discern the improvement in performance, but higher in the range, the advantage of the increased power becomes very noticeable. Percentage increase in the 0-30 m.p.h. acceleration figure is only 8 per cent compared with the standard ID, and this is obtained with full throttle starts from standstill. To obtain full throttle it was found necessary to depress the pedal so that the ankle was turned to a very unnatural angle; considerable wheel tramp and front-end shudder occurred on dry roads, when a fast take-off was made.

All the performance figures listed were taken on a damp surface, and although no front wheel tramp occurred under these conditions it was replaced by wheelspin, unless power was fed in with great care. For this reason, our figures are not as good as those claimed by the manufacturers of the conversion, and probably the times could be improved slightly under ideal conditions.

As with the standard ID, considerable use has to be made of third gear for British road and traffic conditions, since top is deliberately high geared. This was well demonstrated on the maximum speed runs, for against the wind it was not possible to go any faster in top than in third gear. Top gear does come into its own on long straight roads, and the full length of M1 was covered with the speedometer indicating over 90 m.p.h. (this instrument was 4 per cent fast at 50 m.p.h. and 8 per cent at 100 m.p.h.) with effortless ease and little mechanical fuss.

Fuel consumption remains moderate and the overall figure of 23-4 m.p.g. included performance testing and some fairly hard driving in Wales, with a considerable amount of second gear work. There seems good reason to believe that the standard ID consumption can be equalled, and even bettered, if the modified car is driven within the usual capabilities of the standard one. Premium fuel was used for the test, and no oil had to be added to the engine.

Very light brake pedal pressures are called for in town work, and even quick stops from higher speeds require the minimum of effort. The system, however, is not as sensitive and progressive as one might hope for, and the front wheels could be locked on greasy roads, unless care were taken.

None of the tractability has been taken out of the engine — although none has been added—and it is still necessary to change gear rather more frequently than one would expect on a modern 2-litre car. Of importance is the fact that engine operation has not become more harsh than standard, such as has been experienced with some conversions which have passed through our hands.

As might be expected of an engineering firm of Connaught’s reputation, the conversion is well made and assembled, and the car gave no trouble during the 750 miles of test. For those wanting a little more performance still, an even more extensive conversion is offered at further expense.