Two things you pray for when testing a Radical: a dry track and a circuit full of fast curves where its downforce can really be exploited. Spirits were high as I rolled into the Bedford Autodrome under blue skies, then promptly sank when I saw that we could only use a small ribbon of track. You see the new SR4, which replaces the original Clubsport, is just like every other Radical. Here, it wouldn’t get out of third gear and the 1200cc Kawasaki engine – as used in the ZZR 1200 bike, but tweaked to 190bhp at 11,000rpm – wouldn’t have sufficient torque to lunge even the 450kg SR4 out of the tight stuff.
Wrong. Anyone serious about track days – serious as in ‘I’ve mastered the GT3 and want to move up a level’ – needs to sample one of these. Based on an entirely new tubular chassis, with a totally revised aero kit incorporating front-mounted air intakes for the first time on a Radical, it is superb.
Remember that ecstatic feeling when you drove a go-kart for the first time? That’s what the SR4 offers. Something so far removed from any other road car (Caterham included) that it responds just like a race car. Accuracy takes on new levels of calibration: missing an apex by 5cm in the SR4 feels clumsier than not getting round a corner at all in a Porsche Cayenne. In fact, this was a race car, but the difference between it and a car you can drive to the circuit is about £2500 in legal bits.