The sport of drifting is best described as controlled chaos. Racers slide their cars on the ragged edge between slip and grip only inches apart. And while import machines dominate this mechanical ballet, the sport is about to enter a new era...
Where the sport of road racing can be traced back a century to the country roads of Europe, the sport of drifting draws its origins from the serpentine mountain roads of Japan. In the late '80s, a group of racers took to the hills where they perfected their tail-out slides, mastered the art of vehicle control and in the process created an underground culture.
This difficult sport is full of tradition, with many pioneers fielding period-correct cars (imports from the late '80s/early '90s) as the only tools of the trade. But thanks to sanctions like Formula D, this underground hobby has ignited into a worldwide sport. Along with a national racing series, sponsored drivers and factory-backed teams are now the norm. In fact, the suggestion of a non-Japanese drift car would have been blasphemy a few years ago. But now, thanks to its high profile, cars like Mustangs and Vipers are considered successful drift cars.
Until recently, the diversity didn't reach across the pond. But last year saw a 911 enter the fray stateside. In et 6/10 we looked at Dave Blunt's E30 325is drifter, and now GSR Autosport in Anaheim, CA has teamed with pro-racer Michael Essa to create this BMW 350R.
Fortunately, this isn't a riced-out heap. Instead, it's an engineering marvel thanks to the E60 M5's S85B50 5.0L V10 under the hood. In addition, it has a custom Quaife sequential gearbox, one-off quick-change rear-end and a sophisticated brake system that uses no less than three master cylinders - now we're talking!
In some circles, what GSR did to the E92 Coupe would have them sent to the gallows. "We found an '08 335i with just 35000 miles on the clock, it was in perfect condition and ready to be turned into a racer," GSR Autosport Managing Director, Nick Richards said. "It went from intact to a bare shell in under a week," he added.
Richards went on to explain that in three short months, the car went from a stocker to a rocker. But the burning question is why an E92 with S85B50 V10?
"The E92 chassis and suspension are great. It's a solid platform to build on and the V10 was a logical choice since we wanted over 500hp. I also prefer normally aspirated engines," racer and builder, Michael Essa said.
The next logical question was why not upgrade the 335i's twin-turbo N54 3.0 engine? "The limits of the direct injection system on the N54 aren't clear yet, and we needed more power than most tuners were getting from the engine," Richards said. "Instead of investing in taking the fueling beyond 500hp, we went with a known commodity," he added.
But dropping the ten-cylinder under the bonnet proved to be far trickier than anticipated. Several similar conversions have been undertaken in Europe but there were no shops to consult or manuals to reference, so they had to forge their own path.
Once the stock engine was out, the GSR crew found the long inline-six engine had a relatively roomy engine bay. In fact, the compact V10 wasn't far from sliding into place. Or so they thought...
"In the end we had to massage the firewall, modify the steering rack and column as well as fabricate new engine mounts and modify the factory subframe to fit the V10," Essa said.
The V10's electronics are incredibly complex, so GSR found it easier to buy an entire M5 donor car rather than just the engine. This also provided the M5's steering components, complex lubrication system and cooling system.
"We kept the stock oil pan and oiling system since it's super-efficient thanks to multiple electric pumps that eliminate oil starvation under high-g loads," Richards said. "We also swapped the cooling system, which happens to be a double-banked setup, one for each side of the engine."
If that's not crazy enough, the crew at Apex Speed Technologies (AKA Cosworth) had the task of wiring this wonder. They were able to find a heartbeat thanks to a Pectel stand-alone ECU. This go-fast gizmo allowed them to control fuel, spark, the four-cam Vanos, dual drive-by wire throttles, dual oil pumps and variable electronic fan. Oh yeah, they also cut timing between gear changes.
Speaking of shifts, GSR managed to squeeze a Quaife six-speed sequential transmission into the mix. Since clutch action is crucial to a drift run, the third pedal is essential. This necessitated welding the stock bellhousing to the Quaife unit, creating what Richards calls "FrankenTrans".
"The sequential 'box is great. It means a miss-shift is impossible," Essa said.
And since planting the power is just as important as making it, Essa and GSR turned to a custom rear-end. This came in the form of a Speed Way Engineering Quick Change axle, popular with hotrodders. "You can swap axle gears at the track, just pop them in or out," Richards said.
While the axle housing was off-the-shelf, the LSD inside was a custom piece along with Driveshaft Shop axles. The two additions were necessary for the stresses of a 500hp drift car but mounting the assembly required the factory subframe to be cut, modified and reinforced. "The new rear-end was twice the size of the stock unit, so we had to make room for it, then brace everything to support the heavier axle," Essa said.
Moving forwards, GSR addressed the front suspension. "The factory double-control arm system is good, but we reverted to a tried-and-true single mount to curb the massive amounts of camber change during lock-to-lock transitions," Richards said.
In fact, Richards explained that as much as a 20° camber change was measured during left-to-right transitions. This kind of camber changes resulted in substantial toe angles, which led for unpredictable chassis behavior at speed. This peculiar front suspension behavior unfortunately led to part failure at the Long Beach Formula D event.
"One of our front control arms cracked because we underestimated the forces on our new components. It ultimately failed and sent the car into the tirewall," Richards said. "In the end we reworked our setup and have reduced much of the camber and toe changes associated with the earlier setup."
But while the front had teething trouble, the rear was a different matter. "The rear suspension is great. It's one of its best attributes because it allows tons of lateral grip," Essa said. "You need to accelerate while sliding, and the stock multi-link setup allows you to do that," he added.
For braking, GSR turned to Wilwood, using three different master cylinders: one for the massive front brakes, another for the rears, and a third for the e-brake rear calipers. "The car has two sets of rear calipers per side because you use the e-brake a lot to slide the car," Essa said.
Along with its custom pieces, the E92 has off-the-shelf goodies such as KW Clubsport coilovers, 18'' Enkei PF01 wheels and Nitto NT05R tires. To swallow the massive rubber and widen the track, GSR fabricated widebody front fenders and a matching front bumper in carbon. Rear flares were also molded over the stock panels as a stopgap measure. The plan is to build a full body kit in carbon to widen the track about 5'' and further reduce weight by around 100-150 lb. There's also talk of producing this kit for sale, but no decision has been made...
With the season starting as we went to press, the GSR crew regrouped after Long Beach and took 4th place at the Road Atlanta Formula D event against a field of heavy hitters. "We've only had eight dedicated tuning days, so almost getting on the podium with such little time in the car was very encouraging," Essa said.
Despite this, the team is already considering upgrades, including a 5.7L stroker kit for upwards of 600hp, and better weight distribution to get the car away from it's current 54/46 front-rear split. Currently, the car weighs a mere 2800 lb from the stock 3500 lb, but Essa claims there's another 150 lb to be shaved by ditching the stock doors in favor of carbon replacements, etc.
With all this development, we hope to see the European revolution hitting the drift scene hard in 2010.
2008 BMW 335i
Owner: GSR Autosport
Location: Anaheim, CA
Engine: S85B50 5.0L V10 engine swap, AEM DryFlow dual-cone intake, Pectel engine management, GSR Autosport dual 2.5'' exhaust with X-pipe, deleted mufflers and cats, dual in-tank fuel pumps
Drivetrain: six-speed Quaife sequential Quick-change rear-end required a great deal of modification to install, but was needed to cope with stresses of driftingtransmission, Clutch Masters dual-disc clutch, Speed Way Engineering clutch-type quick-change rear differential, custom driveshaft and CV joints, Driveshaft Shop axles
Brakes: 14'' front, 13'' rear Wilwood rotors with six-piston front, four-piston rear calipers, four-piston hand-brake calipers with dedicated master cylinder and hydraulic lever
Suspension: KW Clubsport coilovers, GSR Autosport front control arms, BMW M3 rear control arms, billet aluminum subframe bushings
Wheels & Tires: 18x9'' front, 18x10.5'' rear Enkei PF01 wheels powdercoated orange with 245/40 R18 front, 295/35 R18 rear Nitto NT05R tires
Exterior: GSR carbon widebody front fenders and front bumper and OEM M3 carbon roof, lexan rear windows, pulled rear fenders
Interior: Sparco Pro2000 seats with six-point harnesses and steering wheel, GSR rollcage with race gussets, Pi Omega digital intrument cluster, modified steering column Contact: GSR Autoposrt (gospecracing.com)