Roger Clark Motorsport’s (RCMS’) latest modified Impreza developing over 800bhp has just become a world record holder – running a 9.93-second quarter mile at 143mph at a recent drag event.
This incredible quarter mile makes RCMS’ STi8 the world’s fastest road-legal, manual transmission Impreza – and amazingly it is still only a two-litre EJ20 engine. This bionic drag run makes it the first of the new breed (STi7 onwards) Imprezas to crack into the nines, with previous world drag records being done in the classic GC8 shape cars, most with automatic transmissions out in Australia. The previous best for a manual Impreza was 10.02-seconds at 145mph, run by Dominic Rigoli in his 2.2-litre WRX at Willowbank in Australia.
RCMS’ new world record was set, using officially recognised timing gear run by drag experts Staightliners.com, at the recent Ten Of The Best (TOTB4) modified car event at Elvington airfield near York.
And this phenomenal achievement follows more than a year of research and development – all done in-house at RCMS – taking the car from its 2004 532bhp spec (with the turbo still in its standard position), to its 800+bhp 2005 spec. Needless to say, all this R&D has made the car’s owner, Icelander Halldor Jonsson and his son, Gulli who drives the car, very happy indeed.
The Sonic Blue Impreza has been extensively modified in all areas to RCMS engine builder, Matt Clark’s specifications, using the company’s 20+ years of experience tuning and servicing some of the world’s top rally/modified street cars. It centres around a fully-rebuilt flat four EJ20 engine, with bespoke RCMS steel crank, con rods, pistons, headwork, valve gear, fueling, manifolds, exhaust, intercooler, breathing, ECU and a huge Garret GT3040 turbo at its heart, twisted through 45-degrees for maximum gasflow.
And, on Peter Knight’s engine dyno earlier this year, the outstanding (only two-litre, four cylinder, single turbo) engine produced an almost inconceivable 709bhp at 7500rpm. And that figure was without the help of its 35-150bhp Nitrous Oxide system, which helps it develop more than 850bhp on the drag strip. This makes it one of the most powerful Imprezas in the world.
And way from the phenomenal engine, things are just as well engineered. New for its 2005 specification, the RCMS STi now runs a Modena six-speed dog box, with OS Giken twin plate clutch and in-house flywheel assembly. Then there are uprated hollow driveshafts, a carbonfibre propshaft, fully electronic differential control and an R180 plated rear LSD to help channel the massive power and torque levels, with minimum inertia. Meanwhile, helping to put that down on the tarmac are American Mickey Thompson road-legal drag radials, over 15-inch wheels, hiding a set of custom AP Racing brakes.
As for the suspension, the car doesn’t run specific drag units (as most other drag Imprezas do), but is set up on Ohlins coilovers, with optimised geometry done in-house. This is further complimented by a one-off roll cage by Custom Cages. And the car has also been stripped of some of its weight inside, but amazingly, still weighs 1290Kg without ace driver Gulli in the hot seat.
At the same modified car event last year (TOTB3), Gulli drove the then 532bhp STi up the drag strip in 10.85-seconds – making it the first new shape STi to do a 10-second pass in Europe. But at TOTB4 this year – despite the fact Gulli had only had one short (wet weather) shakedown in the car in its 2005, 800+bhp, dog box equipped spec – Gulli eclipsed that, taking the STi into the record books.
His first run of the day (without the Nitrous Oxide) resulted in a 10.46-second pass at 133mph, and a number of similar European record runs followed. Then, after some adjustments to set-up, the ECU map and the inclusion of all 150bhp of Nitrous Oxide, the car ripped off the line to run its outstanding 9.93-second pass at 143mph.
Driver Gulli said: ‘The 10.04-second run actually felt a lot quicker and smoother, as I was wheel spinning all the way through first gear and into second for the nine-second pass, but I guess that’s drag racing. It certainly felt very fast indeed. I am really very pleased, especially considering I haven’t driven the car for a year, and only had that one wet weather shakedown (which was useless for launching practice), then a couple of practice launches on the day before the event. It was the first time I had driven the car in anger with its new engine and six-speed dog box transmission – which meant I needed four gear changes to run the quarter mile, one more than most cars. Now I can’t wait to see what the car will do at Santa Pod and back home in Iceland. I am sure there’s more to come.’ (31st July 2005)
Specification
Engine........ Flat-four, 1994cc, 16v, turbo
Max Power... 709bhp @ 7500rpm
.................. (+150bhp nitrous oxide)
Max Torque.. 620lb ft @ 5000rpm
Top Speed... 200mph+
0-60mph..... 2.5sec
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