Back in the '80s, motorcycles had the technological advantage over automobiles. Not too many production automobiles had four valves per cylinder, or revved beyond 7000 rpm; meanwhile, a good majority of motorcycles (and nearly all sportbikes) had four valves per cylinder-some even had five-and bikes such as the Japanese domestic-market Honda CBR250RR revved to 17,000 rpm. The after-effect of the oil panics of the '70s was still stunting advances in the automotive performance sector, but with the Japanese bubble economy during the '80s making the domestic motorcycle manufacturers flush with cash, the pace of development in the two-wheeled sector was bouncing off the rev-limiter.
It's a different story these days. Performance automobiles have progressed a hundredfold since the '80s, and the majority of them now bristle with technology that puts even the most advanced motorcycle to shame. "Vehicle stability control" systems can sense what the driver is doing and intervene via brakes and engine detuning to make it nearly impossible to lose control in a corner. Many are equipped with headlights that will swivel into the direction of a turn. There are now systems that can keep the car in its lane if you drift outside the lines with the cruise control activated, or maintain a preset distance from the vehicle ahead of you-heck, one automobile will even parallel park the car for you!
Motorcycles are only now just beginning to enjoy some of the rapid technological development in performance that automobile drivers have already been playing with for years. For instance, even the most basic econo-box automobile has come standard with electronic fuel injection and ABS for decades. Traction control is now all the rage with sportbikes, but that feature has been a staple of automobile dynamic safety control systems for many years. Variable cam timing? Variable-length intakes? Ho hum...numerous production cars have been equipped with those setups since the '90s.
Of course, much of the lag time in advancement with motorcycles can be blamed on the size and weight restrictions to work with their much smaller build, as well as the entirely different and much more complicated handling dynamics of a motorcycle. But the fact remains that automobiles now have the technological edge.
So just how capable is this technology? BMW has already caused quite a stir with its new S 1000 RR superbike. Anyone not living in a cave, however, also knows that the company has been one of the world's premier automobile manufacturers-especially when it comes to performance-for quite some time. We decided to compare the technology in the company's sportiest two- and four-wheel products to get an idea of how much it has advanced the state of motoring performance.
"The Ultimate Driving Machine"
Although it began building motorcycles before automobiles, BMW has cultivated a sterling reputation over the past few decades as a performance automotive company. The rapid rise of its Motorsport division (now known by the singular moniker "M") saw the company making successful forays into numerous auto racing championships, including Formula One. Much of that technology and knowledge became infused in the specialized M versions in BMW's lineup, automobiles that soon gained a status as serious performance vehicles-despite their decidedly non-sports-car platforms.
The M3 is a perfect example. Now in its fourth generation (it first came into being as a limited production racing homologation model in 1986), the latest M3 doesn't immediately strike you as a high performance car. Compared to the stereotypical sports car medium (low-slung profile, cramped cockpit, no creature comforts, etc.), the M3 appears almost pedestrian; based on the BMW 3-series sedans, the M3 seats four passengers comfortably and in surprising luxury (in fact, there are also four-door and convertible versions of the M3). Features such as fully contour-adjustable electric leather seats, a built-in GPS navigation system, climate control, a nice sound system, and a trunk with ample storage space are just a few of the M3's utilitarian attributes that belie the car's performance potential.
The M3's optional 7-speed...
The M3's optional 7-speed dual clutch semi-automatic transmission can be actuated by paddles just behind the steering wheel or with the console gearshift knob. Shifts are so quick that the 0-60 mph acceleration times are .2 seconds quicker than a standard gearbox car.
The optional EDC (Electronic...
The optional EDC (Electronic Damper Control) allows the driver to select from three different damping curves, although unlike current sportbike setups, the settings aren't static. The car's ECU actually monitors driving conditions and is able to change damping curves with split-second speed and accuracy.
Our test M3 was equipped with...
Our test M3 was equipped with the 7-speed dual-clutch semi-automatic sequential transmission. Similar to the new Honda DCT for its VFR1200F, the clutch packs are integrated in one assembly, with each output shaft running a set of gears so that the next gear is always pre-engaged.
And with a 4.0-liter V8 pumping out a claimed 414 horsepower at a dizzying (for an automobile) 8300 rpm accelerating the car to a 0-60 mph time of 4.3 seconds, there's definitely no shortage of performance. Those types of numbers were considered in the elite "supercar" territory back in the '90s, yet BMW has managed to harness them into a package that serenely putts along in urban traffic as competently as it scythes down a mountain road-or racetrack, for that matter. Having the famed 12.8-mile Nürburgring Nordschleife circuit ("Riding the Green Hell", January '08) in its backyard allows the M division to put its engineering to the ultimate test on a daily basis. And the M3's performance there is anything but utilitarian; the latest version is said to be more than three seconds a lap quicker around the Nordschleife than its much more powerful M5 sibling boasting a Formula One-inspired 500-horsepower V10 engine.
Much of the M3's speed boils down to the same performance concepts that have become so prevalent in sportbikes. For example, in order to centralize mass for improved handling, the coupe version of the M3 is the first production car to come standard with a carbon fiber roof. The engine hood is aluminum, and the front fenders are made from a tough thermoplastic; most of the suspension components are also aluminum in construction. The new aluminum-alloy V8 engine is 33 pounds lighter than the much less powerful 3.2-liter six-cylinder it replaced. Granted, the new generation M3 is almost 300 pounds heavier overall than its predecessor, but that gain in performance along with the gain in weight can be correlated with today's literbikes (see Trevitt's "Stop Watch" column in this issue).
Driven By Technology
There's so much technology behind the M3's superb performance that you could fill a telephone book with all the details. For starters, the engine features BMW's "double VANOS" variable cam timing system. While variable cam timing has been seen on many automobile powerplants for years (and the only motorcycle currently sporting variable cam timing is Kawasaki's Concours 14 sport-tourer), a unique aspect of the double VANOS is that both the intake and exhaust camshaft timing are continuously variable by the ECU over a much wider range than previous applications. This allows early valve opening and short overlap for optimum low-end torque, smooth running, and fuel efficiency, along with late opening/abundant valve timing overlap for peak volumetric efficiency at high rpm to give maximum horsepower.
But even more important are the chassis components (or rather, electronics) that help the driver control that power. The M3 is equipped with what is called the "M Drive" system that allows electronic adjustments to various engine, suspension, and steering components so that the driver can custom-tailor the car's behavior for his particular driving style or need. And the settings go far beyond conventional adjustments.
The latest generation M3 coupe...
The latest generation M3 coupe is the first mass production automobile to come standard with a carbon fiber roof. Other outer components such as the aluminum engine hood and thermoplastic front fenders help centralize mass for better handling. Sound familiar?
Interestingly, the M3's front...
Interestingly, the M3's front brakes use single-piston slide calipers to grab its massive 360mm x 30mm vented and cross-drilled discs. Their proven performance shows how important the pad compound/disc friction interface is over flashy items such as six-piston calipers.
The M3's 4.0-liter DOHC V8...
The M3's 4.0-liter DOHC V8 engine cranks out an impressive 414 horsepower at 8300 rpm. Sportbike engines have been treading deep into the 100-horsepower-per-liter output zone for decades, but production automobile engines have only recently begun to exceed this mark.
One is the "Electronic Damper Control" option. Unlike the ESA on BMW's K-bikes or the electronically adjustable Öhlins suspension on Ducati's new Multistrada 1200S, the EDC isn't limited to static settings; instead, it uses various sensors to continuously adjust the shocks' damping according to driving conditions. By measuring aspects such as the car's speed, the front wheel steering angle, and the vertical acceleration of the front and rear axles, the EDC is able to continuously swap between three damping curves in split-second increments via magnetic valves in the shock bodies. The driver can also manually select one of the three damping curves (Comfort, Normal, or Sport) if desired.
The M3 is also equipped with "Servotronic" electronic steering assist. An electromagnetic valve controls the amount of force applied by the steering hydraulics in relation to the driving situation. The power assist progressively decreases as the vehicle speeds up, ostensibly allowing the driver better feel and more precise steering.
Our S 1000 RR test unit came...
Our S 1000 RR test unit came equipped with the BMW accessory Akrapovic slip-on muffler. Performance improvement was minimal, but sound improvement was definitely noticeable, while still remaining relatively quiet at low throttle settings.
It's the BMW DSC (Dynamic Stability Control) that most represents the crossover in technology between the company's automobiles and motorcycles, however. By measuring various parameters (each wheel's speed, throttle position, steering angle, and a gyro sensor to signal when one end of the car is out of line in relation to the corner), the DSC is able to prevent the M3 from losing control in a turn no matter what the driver does by applying brakes to any of the four wheels and/or reducing power. While the Dynamic Traction Control/Race ABS on the S 1000 RR obviously cannot prevent the rider from losing control due to a motorcycle's single-track stance, it's interesting to note that the two-wheel system uses similar parameters (wheel speeds, throttle position, and a gyro sensor for lean angle instead of yaw) to determine when and how much to intervene.
Unlike the S 1000 RR's system, the M3's electronic nannies are even more adjustable once you access the "M Drive" menu in the iDrive dash display. Not only are you able to separately adjust the EDC and Servotronic steering assist, but also the engine's throttle response, and the DSC as well. One similarity though, is setting the DSC to "M Dynamic Mode"; this allows the driver much more freedom to exceed traction limits before it reels everything back in-much like the Slick mode in the DTC/Race ABS on the S 1000 RR sportbike.
How Much Do They Help?
Of course, the real comparison anticipated by everyone was how the systems performed at the limit-or rather, how the car compared against the bike. We wanted to avoid the usual ego-blurred "bike versus car" comparison scenario however, so there are no professional-racer hired guns piloting the vehicles, or ultra-sticky DOT race rubber installed on the machines (although the Metzeler Racetec K3 tires that come stock on the S 1000 RR could be considered hard compound race tires). BMW provided us with an M3 coupe equipped with the optional Dual Clutch Transmission (nearly identical in function to Honda's similar DCT in its new VFR1200F) and a DTC/Race ABS-equipped S 1000 RR. Both vehicles were left stock as delivered from the factory, and we had editor Greg Emmerson from sister Source Interlink Media automobile publication eurotuner
handle the driving duties in the M3 (Emmerson is a highly skilled driver with plenty of experience, and he rides a Yamaha R1 as well), while El Jefe
dealt with the riding chores on the S 1000 RR. As usual, our Racepak G2X GPS-based data acquisition equipment would allow us to see exactly how quick the car or bike was at every point on the track.
Our test venue was the Streets of Willow circuit in Rosamond, California. The tight and twisty 13-turn, 1.8-mile layout of the Streets course would put a premium on braking and cornering-not on acceleration or top-end speed, where the bike's obvious power-to-weight ratio advantage would skew the results.
The M3 makes almost twice...
The M3 makes almost twice as much horsepower as the S 1000 RR from four times the displacement. The M3's measured power is significantly less than the claimed output of 414 horsepower. Many thanks to DC Performance (310/841-6996, www.dcperformance.com
) in Los Angeles for running the M3 on the dyno.
And those results surprised us. Take a look at the data graphs for the details, but on a circuit that we thought would favor the car in many areas, the S 1000 RR showed just how far the state of performance motorcycling has come. For instance, we expected the M3's larger tire contact patches to give it the advantage in most of the corners, but the S 1000 RR matched the car's lateral g-forces in left-hand turns and actually exceeded the car in right-handers. Anyone who's experienced how fiercely today's performance automobiles can bleed off speed with their supremely strong and capable brakes was certainly surprised to see the S 1000 RR achieving deceleration g-force rates that weren't that far off the M3.
An interesting observation by Emmerson was made after examining on-board camera footage from both the car and bike. "I never realized that the Streets of Willow was so bumpy," he said. "On sections where you could clearly see you dealing with major bumps on the bike, the car was smooth as silk. I never recalled any bumpy sections the whole time I was on the track."
While you can see one of the...
While you can see one of the bike's shift points here at about 90 mph, there are no breaks on the car's chart as the DCT reduces shift time to almost nothing. Our friends at Motor Trend (also a Source Interlink publication) provided the Stalker radar gun acceleration data for the M3.
Interestingly, both the bike and the car turned their quickest times with the traction/stability control systems backed off as much as possible. Emmerson ran the M3's EDC system in Normal mode (the Sport mode apparently locks the damping on the stiff setting, while Comfort and Normal are adaptive), and ultimately turned his quickest time with the DSC turned off-but it was only fractionally quicker than his best with the DSC in M Dynamic Mode, and it was "hard work." El Jefe ran the S 1000 RR with the DTC/Race ABS in Slick mode; he said that he probably could have turned a fractionally quicker time with it shut off, but it would have required a lot of effort as well.
Another interesting discussion point was how both Emmerson and Kunitsugu had to "work around" the traction/stability control systems in many sections of the circuit in order to generate the speed they wanted. For instance, Emmerson knew how much the DSC would let the M3's tail hang out, so he selected turn-in and throttle points that took "pre-advantage" of the system's control to put the car in the correct position. Kunitsugu had to do the same in some corners with the bike's DTC; because there are many corners where maximum lean angles exceed the Slick mode's 53-degree threshold point, he had to choose lines that enabled him to lift the bike up off the apex so that full power could be unleashed. Nonetheless, both agreed that the systems are better to have than not for those unexpected situations you may need them.
We're In For A Technology "Spike"
Although automobiles currently have the technological advantage over motorcycles, it appears that tech boom is stalling in the four-wheeled sector. Meanwhile, with MotoGP's electronic wars still raging unabated, that performance technology is only just beginning to trickle its way down to the sportbikes that we can buy on the showroom floor. This means that as the economy gains momentum, it's only a matter of time before we begin to see a surge of motorsport technology that will not only make sportbikes faster, but safer and easier to handle as well.
Just look at what it's done for BMW's M3 and S 1000 RR.
Racepak G2X Data Analysis
In order to accurately record and display how fast each machine was going and where, we strapped our GPS-based data acquisition system to both vehicles during their timed lapping sessions. Some of the results are about what we expected; others, however, are a bit of a surprise. The attached graph displays speed for the car and bike over the course of one lap as we usually show in our comparison tests. New in this graph, however, is a "lap-time difference" trace-in blue-that shows a running tab on the time gap between the car and bike at any point during the lap. A positive value indicates the motorcycle is ahead of the car at that particular spot on the track; likewise, a negative value shows the car ahead of the motorcycle. Note that the lap-time difference is always positive here, indicating the bike is ahead of the car the entire lap.
As shown by the stopwatch, overall performance on the racetrack is a bit lopsided in the bike's favor. While this result was not unexpected (sportbikes are obviously much closer to their racing brethren than automobiles), what did surprise us is how well the motorcycle compared with the car in terms of cornering performance; the S 1000 RR shows more speed not only on the two straights but also in many of the corners. Even though the car is much heavier, we figured that its contact patch/electronic chassis stabilization advantage would enable it to possess higher corner speeds everywhere. Note on the lap-time difference trace that it is almost always increasing, indicating that the bike is steadily pulling away from the car, even in many of the corners. The car shows higher apex speeds in seven of the track's 13 turns, with the bike faster in six corners.
Bike, front straight: 125.4 mph
Car, front straight: 98.4 mph
Bike, back straight: 127.5 mph
Car, back straight: 104.9 mph
As shown in the speed traces on the graph, the bike pulls a huge advantage over the car on both of the Streets of Willow's straights, with more than 20 mph in hand. This equates to a savings of three seconds for the bike in just these two segments, almost half of the 6.5-second difference in total lap time.
Turn 6 segment time
Bike: 3.77 sec.
Car: 4.25 sec.
Turn 11 segment time
Bike: 3.38 sec.
Car: 3.98 sec.
These two segments account for another full second in the bike's favor, with the bike carrying more speed as can be seen clearly in the graph. Both these turns fall in the middle of a series of corners and show how the track is more open for the motorcycle than for the car. The width of the car means any chicane or switchback is correspondingly tighter for the car than for the bike, and the bike can take a straighter and faster line through the section. In the tighter Turn 11 section, the difference in speed between the car and bike is significant, but the slower speeds equate to a similar time gap as seen in the more open section that includes Turn 6.
These graphs plot lateral g-force against longitudinal g-force for the car and bike; data from an entire lapping session rather than just a single lap was used, and the traces represent the maximum combined values recorded during the session. These traces also represent the traction circle for the car and bike, and show some significant differences. The top half of the chart represents acceleration, and it's clear that the bike can accelerate harder than the car; the peak value recorded for the motorcycle is .8g, while the car reaches just over .5g. The lower half of the chart is deceleration, and here the car holds an advantage, with maximum braking of just over 1g compared to the bike's maximum of approximately .8g. In terms of lateral acceleration, the right half of the chart represents the right-hand turns on the course; the left half, the left-hand turns. On the left side of the chart, it's a draw between the bike and car with a maximum of 1.2g for each; on the right side, the bike holds an advantage with more than 1.5g compared with the car's 1.2g. Why the discrepancy? This portion of the traction circle is largely determined by performance in the Streets of Willow's banked bowl turn, where the bike can take advantage of the additional camber offered while the car seemingly cannot. In this turn, segment 8 on the data graph, the bike holds this higher lateral g-force momentarily and there is only a slight difference in speed between the car and bike. Still, this turn accounts for a 4 mph apex speed differential and a further .3 seconds gap in lap time between the two vehicles.
The four quadrants of the traction circle show combinations of lateral and longitudinal g-forces. For example, the top right quadrant represents acceleration while turning right while the bottom left quadrant represents braking into a left-hand turn. Note that the car, in addition to braking harder than the bike, is able to combine more braking and cornering forces than the bike is capable of. In other words, the car trail brakes into corners better than the motorcycle. This is also seen on the lap-time difference graph, where the car gains more than a quarter-second on the bike entering most corners.
||BMW S 1000 RR
||$13,800 ($15,730 as tested with DTC,
Race ABS, GSA)
||$58,400 ($66,400 as tested with Melbourne Red Metallic paint, Technology package, M Double-clutch Transmission with Drivelogic and Gas Guzzler Tax)
||Liquid-cooled, transverse, 4-stroke four
||Liquid-cooled, 4-stroke V-eight
|Bore x stroke
||80.0 x 49.7mm
||75.2 x 92.0mm
||BMS-KP EFI, single-valve 48mm throttle bodies, dual injectors/ cylinder
||High-speed concept with single butterflies
||46mm inverted cartridge fork, 4.9 in. travel
||Aluminium two-joint spring strut axle with tiebar; small positive steering roll radius; compensation of lateral forces; anti-dive
||Single shock absorber, 5.1 in. travel
||Five-arm lightweight axle with anti-squat and anti-dive
||120/70ZR-17 Metzeler Racetec K3
||245/40ZR-18 Michelin Pilot Sport
||190/55ZR-17 Metzeler Racetec K3
||265/40ZR-18 Michelin Pilot Sport
||Double disc brake with BMW disc mount, 320mm, radial 4-piston fixed calipers
||Single-piston swing-caliper compound disc brakes, 360 x 30mm, vented and cross-drilled
||Single disc brake, 220mm, single-piston floating caliper
||Single-piston swing-caliper compound disc brakes, 350 x 24mm, vented and cross-drilled
||56.4 in. (1432mm)
||108.7 in. (2761mm)
||461 lb. (209 kg) wet; 433 lb. (196 kg) dry
||3520 lb. (1600 kg) unladen, to DIN/EU