With a turbo the size of a small country, lag can be a problem. Adding two bottles of nitrous oxide-one for feeding the engine and the other for cooling-solved this problem. "I'm not really bothered with the gas at the moment," Keith says. Although they splashed the cash for a huge range of products, they were also happy to provide their own parts, should the need arise. The pair fabricated their own cooling rail for the intercooler. Buying one would have cost 120, so they made their own for 10, which feeds gas under pressure from both ends of the rail and proved more effective than the one they had in mind. The other tank feeds the 75bhp engine jets. They also fabricated their own stainless steel exhaust system, as they just couldn't find one they liked. "Some people run a 3-inch downpipe from the GT45 turbo to the 4-inch exhaust, but we designed our own 90mm downpipe to connect to the exhaust. In our opinion, you can't get better than that," Adam says.
The Supra was also subjected to a crash diet. "It was me, really, who wanted the interior stripped out. I took it down to a bare shell," Adam says. "I spent ages chipping away at the soundproofing-that's helped in terms of weight reduction. The standard fuel tank was huge and heavy and has since been replaced with a lightweight custom-built one; we designed the entire fuel system that goes along with it." They admit the car is well over spec'd-the fuel system in particular-to be sure, the engine has no chance of ever running lean. All these changes, together with the AEM engine management, also meant the standard wiring had to be replaced with a custom loom.
The final setup and tuning was carried out by Dan at Turbofit, one of the UK's top Supra tuners. "He was shocked and amazed that we had built the car ourselves," Keith says. "He thought we were a tuning company." The car recorded 571 bhp at just 1 bar of boost. "We were expecting about 500 bhp at 1.3 bar. We just couldn't believe it," he says. They have since been advised that the car could cope with up to 1.8 bar, which should provide in excess of 800 bhp-and that's before the nitrous oxide has even been engaged. The original auto box was replaced with a manual before they got to this stage in the project though.
During practice launches Keith says that he was dropping the clutch at 5,500 rpm and the car hit 55 mph in first gear, 90 in second and 125 in third. "It doesn't really want to drive below 2,000 rpm and from then on it gets a bit hairy," he continued. "It hits full boost at about 4,000 rpm, but when you change at 7,000, it only drops back to 4,000 again so it's nearly on full boost all the time once you get going." So far there is no real lag so the gas has not been required.
The future for this Mark III? People have commented that with these specifications and the boost turned up, we're looking at a potential 10-second car. Keith knows that the drivetrain is a weak link, so that's on the schedule for improvements. They will also be replacing the glass with plastic and fitting a carbon-fiber bonnet to lose even more weight. The target, a 10-second run, is surely within grasp.