The Independent American Magazine for all Mini Owners
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many hours of checking the suspension and steering geometry to ensure mechanical compliance. Undeterred by what would be a Herculean task, Dave discovered that the Volkswagen motor and transmission would fit physically within the MINI’s engine bay and he started designing his own location mountings. Compared to the original unit, more space was left behind the engine, to allow enough room for both the exhaust and turbocharger, which cancelled the need to cut into the body’s firewall. Three crash-damaged Volkswagens yielded not only engines and 7KH 9: UXQQLQJ JHDU ÀWV VQXJO\ ZLWKLQ WKH VWDQGDUG 0,1, HQJLQH ED\ Cooper S for less than half of its market value, Dave had a MINI on which he could experiment. It did not matter that the brakes, exhaust, clutch, radiator and power steering pump were all worn-out; he had more ambitious plans for the car. “From running various road cars, I have been impressed with the performance, reliability and sheer tune-ability of Volkswagen’s 20-valve, 1.8-liter turbocharged unit,” says Dave. “The main problem with the cars that are powered by this engine, such as the VW Golf, Vento, Passat and the Audi TT, is that the bodies are very heavy.” In Dave’s eyes, the strong and willing 1800cc turbocharged powerplant and the somewhat lighter MINI body would be a winning combination. However, changing entire drive-trains is a complicated procedure, not only in terms of whether or not the actual engine and transmission would fit into the MINI’s bodyshell but also the integration of the fuel, electronics and cooling systems that would present their own challenges. Dave reported that bespoke driveshafts, which would fit into the MINI’s standard hubs, had to be made, and this involved transmissions, but also their associated electronic hardware and wiring. Not only did all of this need to be plumbed in, including the relevant oil and water cooling systems, the throttle control, the stick-shift lever, the clutch operation and the engine-driven power-assisted steering mechanisms, but the Volkswagen electronics also had to be modified to communicate with the MINI’s original Body Control Module. This is where Dave’s vast expertise in electronics was tested to fresh extremes. Decoding the Volkswagen’s ECU was necessary, in order that the MINI’s systems could retain control over the immobilizer, so that the original ignition key could be retained. However, the MINI’s electronics were unfit to control the new engine, due to the extra sensors that Volkswagen had integrated within the turbocharger’s manifold. Dave justified his belief that the engine’s use of both exhaust gas temperature and air/fuel mixture sensors was an important reason for him to choose the 1.8-liter turbo unit as a suitable donor engine, when he stated, “The supercharged MINI engine does not possess more sophisticated engine management, which will cut the power, once it detects a risk of engine damage,” remarked Dave. “Furthermore, not many aftermarket ECUs have the facility to control these extra sensors and using the original Volkswagen electronics package was deemed the most obvious solution.” The Best Of Both Worlds The first test drive revealed a substantial increase in performance, over Dave’s previously modified Cooper S. Unfortunately, the high level of torque produced meant that the replacement engine managed to ‘corkscrew’ his original drive-shafts, so replacement shafts be fabricated from high-tensile steel. As they are limited by their size, the MINI’s original outer CV joints were retained, but had to be strengthened by having their inner cages removed and shot-peened, prior to reassembly. As the Volkswagen motor runs considerably cooler than the supercharged Tritec unit, not only is fuel economy enhanced, a factor proven by Dave recording up to 150 additional miles per tank of premium unleaded gas, but also a smaller-than-standard coolant radiator was needed. Dave has also modified the hydraulics of the power assisted steering so that the pump is run by the engine, but had to install an additional oil cooler to keep things cool. Prior to being subjected to a long-term test, the Volkswagen ECU was remapped by a tuning specialist, to match the engine’s power delivery to the MINI’s lighter body. Initially, the engine’s peak torque was calculated at 374lbs ft at only 2,200rpm, with a maximum power output of close to 300bhp, compared with the original Cooper S’s zenith of 163bhp. However, Dave was concerned that the car was overpowered for road use and, even at the current detuned level of 345lbs ft and 275bhp respectively, the car is still quite a handful. Driving Impressions Dave’s intentions to use the car on-track are immediately obvious, from the need to clamber over the installed roll cage to gain access to the cockpit. The array of additional gauges, switches and warning lamps are intended to both inform the driver and to give maximum control under racing conditions. An almost complete absence of trim, from rear seats to the headlining, plus the installation of transparent Lexan windows, has made the car 44lbs lighter than a standard R53 Cooper S. Although starting the engine is a common procedure to MINI owners, the deep growl that bellows from the bluff front-end of Dave’s 22 www.mc2magazine.com