When Roger Clark Motorsport needed a name for its latest demonstrator, it looked to the world of confectionary and settled on Gobstopper--presumably because this car leaves people speechless. But you can't help thinking that the American equivalent--Jawbreaker--would be more appropriate for one of the fastest Imprezas in the world.
This British operation has a massive reputation to live up to after winning the London to Sydney marathon, a bagful of national rallying titles, and a world quarter-mile record for a manual-shift Impreza. It was decided to throw everything at this demo car--one that would hammer the drag strips and circuits of Europe in the hands of family member Matt Clark. The resulting 850bhp monster was bound to prove explosive.
Pure horsepower can't explain the near-frightening acceleration: this beast will hit 60mph in approximately three seconds. With 7000rpm dialed in, it needs launch control to get off the line at all. Low nine-second quarter-mile times with trap speeds over 140mph are almost a given and it'll keep going all the way to 200mph--something the company hopes to set more records for in the near future.
Perhaps it's insane that this machine is fully road legal (with the right exhaust) and pretty much every part is on sale to any Impreza owner wishing to take on sound and light in a straight race. It even looks like a factory offering; delete the decals and a deaf policeman would mistake it for one of many dressed-up Scoobies that roam the roads of Europe. Unless they had a radar gun.
RCMS wanted a classic shape and settled on a last-of-line WRX STI Version VI Type R two-door, which came with a lightweight frame and in-built stiffness thanks to two less doorframes. There weren't many made to begin with and this one came with a Prodrive WRC wide arch kit, complete with bumpers. It was a rare find and some enthusiasts will weep to see one ripped apart, until they see what has been done with it.
The car was stripped and acid-dipped before the FIA-approved T45 multi-point rollcage went in to brace the shell. Then work began on the engine, which is an engineering masterclass. It started as a straightforward 2.0-liter EJ20 closed-deck Subaru block, but open up the vented and reverse-scooped hood and the world of wonders confirms this is about all it shares with a stock model.
Gobstopper is bedecked with polished components, carbon-fiber, and an almighty ball-bearing Garrett GT35/40 turbocharger, complete with its fist-sized inlet, 44mm wastegate, plus its own speed sensor to prevent it spinning out of control when the 12-pound bottle of nitrous oxide (mounted in the trunk and wrapped in a heating jacket) gets kicked into life. Theoretically, it's good for another 450bhp, although with that much boost, vital components would start to melt, so 25 percent is realistically all that will get used.
It takes a 3.5-inch ceramic-coated, stainless steel exhaust to vent the gas. That's bent around the back of the enormous 5.5-liter oil sump to reduce the length of the pipes while quick-release clamps allow the silenced exhausts to be switched for straight-cut versions in a matter of minutes. With those in place, it sounds like Hell is calling.