1986 Boulder Boxline SW4 RS TwinTurbo
The Boulder Boxline SW4 was a bespoke version of Boulder’s Boxline SWB compact SUV, featuring 4-wheel independent suspension, fiberglass bodywork with huge fender flares, and a turbocharged, AWD layout. It was intended to compete in Group B rallying. However, by the time the vehicle was ready for competition in 1985, Peugeot’s tube frame, mid-engine 205 T16 had proven that production-based, front-engined rally cars were no longer truly competitive. The Boulder competed in a few events in 1985 but was not particularly successful.
In 1986, rather than creating additional homologation or competition models, Boulder took the widebody, fiberglass frankenstein of a trucklet in a different direction. The RSTT (RWD, Street, Twin Turbo) changed the homologation special into a brawny, luxurious muscle truck. Instead of the proprietary, high-strung 2.1L DOHC I5 turbo from the rally homologation model, the RSTT used of a modified version of a large, aluminum-block SOHC V6 already in mass production. Featuring a 4 valve head, electronic port fuel injection, twin turbos, and a displacement of 4.4 liters, it sends 350 hp to the rear wheels through a 4 speed automatic. The interior borrows from the Turból parts bin, with deep bucket seats swathed in rich velour and thick application of sound deadening. ABS came standard, a first for any Boulder model.
Engine: 4.4L twin turbo V6, 350 hp, 315 lbft torque
Transmission: 4 speed automatic
0-62 mph: 4.8s.
1/4 mile: 12.9s
Top Speed: 152 mph
Weight: 1042 kg
I admit this was a bit of a rush job. I hadn’t initially planned on entering, but after work today I was curious to see if I could modify one of my Group B cars to fit the criteria, which, by the time I had got there, I would have felt silly not to enter it. In hindsight, it would have been wiser to use mu pre-existing ‘85 Premium GT car as a base rather than a rally car, but too late for that now. Styling is more basic than I would like, but I was up against the clock. I also didn’t get the chance to test it in beam, so how it performs will be interesting, to say the least.