For Brodie Brittain Racing the commission to produce a turbo conversion for the Mazda MX-5 was a significant step in the development of their business. It took them out of the sphere of what Dave Brodie modestly describes as run of the mill tuning shops. Some mill. The BBR reputation among racing and fast road cognoscenti was already impressive, and it wasn’t because they were run of the mill that they won a commission that was also being sought by such names as Tom Walkinshaw Racing and Turbo Technics. It was because they produced genuinely well engineered and reliable turbo performance conversions for a host of cars, most famously the Cosworth. It was because when they talk about horsepower they mean horses not Shetland ponies. And I guess it was also because they have a refreshing, no-nonsense attitude to engineering, and a noticeable desire to produce the best possible, in spite of cost and man hours.
The brief from Mazda UK was not an easy one, not least because the inside of the engine had to be left well alone. That meant keeping the 9.4:1 compression ratio, unusually high for a turbo engine, and also retaining the pistons, camshaft etc. In fact the conversion had to come in a kit form that could be sent to any one of 70 Mazda dealers. It had to be easy to assemble, and to coin a horrible phrase, user friendly. Two specially trained staff at each of the Mazda dealers, and an instruction book that makes Airfix model instructions read like hieroglyphics in comparison, ensures against any incorrect assembly of the unit. The conversion comes with a three year warranty. The end result: an MX-5 with a sting in its tail. Power is pushed up from 114 to 151 bhp and more significantly torque rises from 100 to 154 lb ft.
Given that the engine internals are untouched, and it is receiving a 37 bhp kick in the pants, one would be tempted to worry about the reliability, despite the assurances of the warranty. But a significant help in the conversion process was, according to BBR, the very strong Mazda engine. I can endorse their view, having a Mazda 323 1.6 turbo with 75,000 on the clock, which is still apparently bullet proof. Brodie wanted to be sure however, and so much of the testing involved putting the engine through the worst possible conditions (ones similar to how a lot of people will probably drive it). The unit for prototype modification was 25,000 miles old in the first place. It was dyno tested for 300 hours, and then run for a 100-hour endurance test at various rpm and degrees of boost. Once installed Brodie took it twice round the M25 at 7000 rpm in third. Unbreakable, it seemed like the perfect unit to modify.
BBR made a quote to Mazda based on the fact that they would not be content with any compromise in the quality of the package. It could be done cheaper, but not better, and the quality of the castings, hoses and appliances testifies to the overall quality of the conversion. BBR claim to be the only tuning house in England who could have done the work (design, manufacture and development) in-house, and inside twenty weeks.
The heart of the conversion is a sophisticated engine management system. “The art of turbocharging is all about managing the engine on boost,” say BBR, who designed and manufactured this system, which is fitted with a boost sensor, and takes over from the normal management system when the turbo pressure starts to build. Boost is kept at a modest 0.5 bar; although the turbo could handle more the high compression ratio limits the breathing ability of the engine. The potential performance is therefore effectively limited by the nature of the brief from Mazda UK, and to keep the Mazda warranty 150 bhp is the limit.
But what if you’re a real adrenalin freak? BBR are working on what they describe as a phase 2 conversion, that pushes out 230 + bhp, although this comes without the Mazda sanction, and the work can only be done by BBR. Obviously the engine undergoes a considerable amount of redesigning, is given a lower compression ratio, is balanced and rebuilt, and is fitted with a bigger intercooler, new injectors and a different engine management system. 230 bhp powering a car which weighs 985 kg should make a fair number of Porsche and Ferrari owners regret the hole in their pockets, and add up to a fairly serious grinnability factor.
BBR see the Mazda commission as the start of more serious projects. They have a policy of business expansion, much of the profit being ploughed back in to the business, and they are in the process of enlarging the workshop premises. They already have one of the best dynometers in the country, capable of running to 14,000 rpm and 1400 bhp. There is a prototype machine shop, and essentially they are capable of carrying out extensive engine modifications, designing and building performance engines from scratch entirely in-house. But their work also extends to sophisticated electrical engineering. They have a department which can design and manufacture engine management systems, and they have a fuel injection test rig which they will be marketing to other tuning companies, that measures voltage, pulse and frequency against flow. Amongst other projects they were willing to tell me about they are developing an LCD instrument display for racing cars. Its most immediate advantage over a set of conventional instruments is that it is easy to fit, and considerably more affordable. The instrument monitors up to nine essential elements, from oil pressure and turbo boost through to tyre temperatures. The display only shows one element at a time, giving priority to water temperature except on the starting grid when it shows rpm. If at any point during the race one of the other elements, the oil pressure for example, becomes critical it will flash up on to the screen. During the race itself the engine rpm are indicated by a ‘traffic light’ system that progresses from green through to red the closer the engine speed is to the rev limiter. Once the unit is proven in their race cars it will be marketed with the aim of supplying affordable instruments to the club racer.
BBR have their eyes firmly fixed on the future, on establishing themselves as a company capable of every aspect of performance engine design and development, with many other innovative irons in the fire as well. Their level of professionalism and enthusiasm and the wealth of ideas flying around their Brackley base should put that vision just around the corner. — CSR-W