Modified test on a Vauxhall with the Brabham kit plus cylinder-head conversion
Vauxhall is the third British manufacturer to secure the name of a champion grand prix marque for a production car but the first to have a model associated with the world champion racing driver, so if the kudos pays off in terms of production their new Viva kit should enjoy unrivalled success. Even before this hot Viva was announced we had spotted Jack Brabham’s “personal” version at the Racing Car Show and this is the subject of our test this month.
With such a new car, there is confusion building up about the type names, so we had better explain that the basic Viva delivers an estimated 47 b.h.p. net from its 4-cylinder 1,159 c.c. engine. The “90,” which has a higher-lift camshaft and other minor improvements, gives about 60 b.h.p. and has disc brakes as standard equipment. Then the 69 b.h.p. Brabham kit for the Viva, costing £37 10s. and consisting of twin Stromberg carburetters, manifolding and special exhaust system, is available only for the “90,” fitted by the dealers, while the car we tested was also fitted with a modified cylinder head costing £29 10s. on exchange. With modified combustion chambers and 10:1 compression, this is said to produce 78 b.h.p. net from the Viva engine and without any other extras, this output is available for a total of £730 on the “90” or £775 on the more luxurious “SL 90.”
On a cost/performance basis the “Stage 2” conversion (we are at loss for a title) offers extremely good value for money, since the car will hold its own against larger GT-designated models costing at least £100 more, and not sacrifice much in the way of carrying capacity either. However, it is always necessary to work the gearbox freely on a small high performance unit and a driver would need to work fairly hard to keep up with a Cortina GT, for instance.
The “Brabham” Brabham Viva stands out among other small cars without being ostentatious due to a new type of transfer sweeping white lines across the dark green bonnet, tapering down the sides with Brabham’s name. Passers-by dropped their gaze to the 5-1/2J wheels, shod with SP41 tyres, and nodded wisely . . . Other extras included an oil cooler (£13 10s.), a woodrim steering wheel with Brabham motif (£8 10s.), a binnacle tachometer (£12 14s. 6d.) and Koni shock-absorbers costing £20 for the full set. Lowered suspension is still in the experimental stage, not quoted at the moment, and the engine was balanced (by Repco, of course). The wheels cost £18 10s. for four on exchange, and the specification is concluded with a pair of Cox safety seats with integral inertia reel harness lap-and-diagonal belts—with headrests, they cost £31 10s. each.
At first the car was, if anything, disappointing, as it did not seem to have a searing power curve, but the acceleration times proved that it was deceptively fast. A little choke was needed to keep the engine running when cold and apart from a noticeably throaty noise disguised by lightweight pancake air filters there was little to suggest to passengers that this was a modified car. A driver, especially one used to Vivas, would notice much better pick-up above 3,000 r.p.m., and even with the standard “90” cam the engine can be felt to fluff below 2,000 r.p.m. while giving a most distinct advantage between 4,000 and 6,500 revs. (7,000 can be used in emergency, but our speeds in gears are quoted at the lower limit.)
Selection of carburetter needles to suit the induction system was still in the experimental stage when we drove the car, and certainly the engine was running too rich at low speed. The overall fuel consumption of 20.8 m.p.g. was far worse than expected, indeed there is no physical reason why the tuned car should not be as economical as the ordinary “90” in normal driving, and flooding was evident at times in low-speed pick-up. Overall, however, the engine performed very smoothly and the excellent gear-change makes it a pleasure to drive the car quickly. Our maximum speed of 92 m.p.h. was not achieved in ideal conditions, and a speed approaching 100 m.p.h. is claimed for the car. With lowered springs, wide rim wheels and Koni shock-absorbers all round the handling could hardly be better for road work, although on bumpy roads the ride became somewhat uncomfortable, especially at low speed when something like a drainhole can really jar the front suspension. Roadholding powers were extremely good and roll-free, marked by fairly strong understeer, and it was even possible to lift the inside rear wheel cornering hard on wet roads which is a fair measure of adhesion.
In summary, the Brabham Viva as tested performs most creditably and even in standard form the Viva 90 has good brakes, suspension and gearbox which match up to the performance image. Since the model is still new to us, we can remark that it is a very spacious, comfortable car for the money, rather spoilt by the “progressive” throttle which makes good starts difficult, a faulty fuel gauge, by tinny quarterlight catches and the plastic cubbyholes which let cameras, stopwatches, etc., slide about helplessly and noisily when the car is in motion.
Of the optional equipment, the oil cooler is no doubt useful for long high-speed autostrada trips, and the rev-counter more than a mere accessory for hard drivers. It was particularly interesting to try the Cox safety seats with their integral inertia reel belts which are quite comfortable to wear. The seats are big and heavy, too upright for our liking but that is a matter of adjustment on the runners, and with firm cushions felt perfectly comfortable. It is now possible to get fore-and-aft adjustment, which is progress, but the seats are only suitable for 4-door cars as they cannot be tilted.—M. L. C.
Speeds in gears (m.p.h.):
1st… 25 (6,500 rpm)
Overall fuel consumption: 20.8 m.p.g.
Conversion by: Jack Brabham Conversions Ltd., 131-139 Goldsworth Road, Woking, Surrey.