Yank the emergency brake in the new Mazdaspeed6 at speed and the car's all-wheel-drive system automatically disengages drive to the rear wheels. The fact that this ham-fisted, ass-out, "Dukes of Hazzard" buffoonery was a design consideration is Mazda's way of saying it cares.
The "zoom-zoom" Mazda6, whose superb chassis and eager V6 have inspired positive reviews and solid sales, has nonetheless fought for parking spaces among the enthusiast population.
Mazda invited us to hammer on early prototypes of the new Mazdaspeed6 at the 1.7-mile TI Circuit in Okayama, Japan. Home to two F1 races in the mid-'90s and a favored JGTC track, TI Circuit offers flat-out sweepers and long straights with several hairpins. Its liquid-black pavement is smoother than R Kelly, but didn't offer the real-world driving conditions we need to wholly evaluate a proper all-wheel-drive sedan.
That's right, all-wheel drive. And that V6? It's gone too, in favor of a turbocharged version of Mazda/Ford's 2.3-liter inline four. The heart of the Mazdaspeed6 is the most powerful Mazda engine currently in production.
Mazda, which until recently suffered with relatively low-tech piston engines, revamped its entire line with an infusion of technology. The basic architecture of the Mazdaspeed6's 2.3-liter is shared with the inline, aluminum MZR four also used in the Mazda3, but features a host of Mazda's newest technologies.
Most notably, fuel is injected directly into the combustion chamber with Mazda's Direct Injection Spark Ignition (DISI) system. Direct injection, which reaps performance, emissions and fuel economy benefits in normally aspirated engines, pays even bigger dividends when coupled with forced induction. Injecting gasoline directly into the combustion chamber cools the charge, increasing boost response, low and midrange torque production, and allowing for a high compression ratio and healthy boost due to better knock resistance.
The Mazdaspeed6 brings 15.6 psi to bear on 9.5:1 compression pistons, barely down from the 9.7:1 pistons found in the naturally aspirated engine. Mazda chose a Hitachi turbocharger using Borg Warner internals. This small unit contributes to the engine's excellent torque production and throttle response, and its small thermal mass shortens catalytic converter light-off time for improved cold-start emissions.
Although the engine redlines at 6700 rpm, it has little to give after 6000, where it feels like the little turbo simply runs out of headroom. It does, however, provide nearly 100 percent of its claimed 280 lb-ft of torque from just 2500 rpm, and remains flat until 5500 rpm, where the engine makes its peak horsepower figure of 274. Mazda claims a 0-to-60 sprint of 6.6 seconds, which is a bit pessimistic.
Interestingly, the intercooler sits directly on top of the valve cover. Mazda argues the cooler intake charge resulting from direct injection still meets efficiency targets with the intercooler in this location. It's no secret this positioning also significantly reduces flow through the core, makes packaging the engine easier and production cheaper.
But efforts were made to get air through the intercooler. A trick, two-piece ram-air duct supplies fresh high-pressure air at speed. The intercooler is housed in a box, which seals against molded plastic ductwork attached to the underside of the hood. Ram air nostrils draw air from under the leading edge of the hood.
The exhaust note is well tuned inside the cabin, but from the outside sounds like a linebacker exhaling through a cocktail straw-backpressure in D flat. Engineers hinted the engine endured extended bouts with more than 15.6 psi during testing with no ill results; a stiffer block, forged crankshaft and steel connecting rods offer proper credentials.
There is certainly power to be had from uncorking the exhaust. But once power figures start growing, the issue of whether the aftermarket can meet the challenge of a necessary bump in fueling, given the complexity of the ultrahigh-pressure direct-ignition fuel system, remains.
In a direct injection engine, the injectors can only fire during the compression stroke vs. constantly in an engine with port injection, which may explain some of the softness we felt after 6000 rpm as injectors struggled to inject more fuel in less time.
Our best advice is to use conventional auxiliary injectors in the manifold for added fueling once beyond the capacity of the DI system. Combine those with a front-mount intercooler and larger turbo and you'll have a legitimate powertrain capable of serious numbers.
Mazda gets big kudos for its newly developed six-speed manual transmission whose compact three-shaft design keeps dimensions equal to those of the five-speed model. Double- and triple-cone synchronizers, some of which are made from high-carbon steel, combine to create smooth and positive shift action. Wide gear ratios take advantage of the engine's prodigious torque output and provide decent fuel economy, in the neighborhood of 27 mpg on the highway.
Mazda worked with LUK to create the Active Torque Split All-Wheel-Drive System that uses an electro-mechanical clutch pack with a water-cooled "power take-off unit" to feed up to 50 percent of torque to the rear wheels. The system uses sensors that measure g-forces, yaw, throttle position, wheel speed and steering position to apportion torque.
It features three automatic modes, which are not manually selectable: Normal, Sport and Snow. Under normal driving conditions, 100 percent of engine output is fed through the front axles. Start making lateral demands and the Sport mode instructs a three-piece rear-drive shaft to twist into a Tochigi-Fuji manufactured rear limited-slip differential (the same type found in the RX-8). The sport mode is smart enough to hold the 50/50 split through the exit of a corner to aid in rotation. The front differential is open. In Snow mode, the clutch pack locks torque split at 50/50.
Chassis rigidity was increased by 50 percent over the Mazda6's, whose chassis is no Gummy worm. High-tensile steel was added to areas like the cross member, cowl and rear diagonal braces, with increased numbers of joints and gussets. This extra bracing, combined with the all-wheel-drive system, adds around 330 pounds; the car should arrive at around 3,500 pounds.
Increased rigidity pays dividends in ride and especially in high-speed stability, one of the Mazdaspeed6's strengths. We whipped through a lane-change chicane on the back straight at stupid velocities with utmost confidence.
Monotube, rather than twin-tube dampers, feature larger diameter shafts and more aggressive valving controls springs that are 25 percent stiffer in the front and 37 percent in the rear. Anti-roll bar diameter increased by 1mm in the front and 2mm in the rear, and front lower wishbones and rear multilink bushings use harder durometer rubber. The installation of the AWD system necessitated a slightly higher ride height than the standard 6.
The TI circuit was soaked during the morning session, which tested the 215/45-18 Bridgestone Potenzas as much as the car's AWD system. Mounted on 18x7-inch wheels, the tires get fully utilized. While the car isn't necessarily undertired, it feels like more rubber would be a plus. In the wet, the Mazdaspeed6 employed understeer as its primary defense against excessive speed. No matter how hard and sideways we threw the car into a corner, mashing the power just encouraged safe understeer. We were told wet handling will be adjusted to make the car more driveable.
When faced with a dry track, the Mazdaspeed6 demonstrated an entirely different character. It was drawn toward the apex by the gentle persuasion of a left foot on the brake pedal, and all that torque made it easy to stream out of corners both fast and slow. We didn't experience as much power-on rotation as we expected given the torque split and rear limited-slip.
Although the car features an electronic throttle, there is no penalty for overlapping the throttle and brake pedal. The Mazdaspeed6 is a comfortable, willing partner that's happier to help you safely exit a compromising corner rather than punish you for a talent deficit.
Single-piston calipers remain at all four corners, but discs have grown to a healthy 12.6 inches in the front and 12.4 inches in the rear. ABS remains standard. The Mazdaspeed6 had no problem hauling down repeatedly from license-revoking velocities, but the cars we drove were fitted with prototype track-duty pads that will be available through Mazdaspeed. We'll have to wait for a production car to pass final judgement.
Aesthetic enhancements, just like the mechanical bits, are integrated: All the sheet metal forward of the A-pillar is new. The fenders are flared to fit larger rollers, and the hood is 45mm taller to fit the top-mount intercooler. A new rear bumper incorporates the dual exhaust tips and even a functional diffuser; a mild spoiler sits on the trunk.
The Mazdaspeed6 looks both aggressive and elegant, exactly the duality that defines the car's essence. Still, with this much body revision we can't help but question whether cost savings were realized in production by the top-mount intercooler.
Inside the car, three-way power semibucket seats are more supportive than those in the regular 6, but still need additional bolstering, especially in the shoulder area. Upmarket touches include an adjustable tilt-and-reach steering wheel, chrome-ringed gauges, new center console and upgraded soft-touch materials.
The Mazdaspeed6 should be in showrooms by the end of April. Expect a price tag starting in the neighborhood of $28,000. Mazda has a successful habit of entering niches it creates itself or convinces us we need, and no one dares enter the STi-vs.-EVO fray, including Mazda.
The Hiroshima-based manufacturer hopes its blend of serious performance, sophistication and affordability offer an enticing alternative to a segment dominated by BMWs, Audis and Mercedes, and perhaps to those for whom the edge on the rally-bred monsters is too hard.
We look forward to time with the Mazdaspeed6 on the street. You can expect a road test soon.
2006 Mazdaspeed6Estimated Price: $27,000EngineEngine Code: MZRType: Inline four, aluminum block and headValvetrain: DOHC, four valves per cylinder, direct injectionDisplacement: 2261ccBore x Stroke: 87.50mmx94.00mmCompression Ratio: 9.5:1Claimed Crank Hp: 274 hp @ 5500 rpmClaimed Crank Torque: 280 lb-ft @ 3300 rpmRedline: 6700 rpm
DrivetrainLayout: Transverse front engine, all-wheel drive
TransmissionGear Ratios 1st Gear: 3.538:12nd Gear: 2.238:13rd Gear: 1.535:14th Gear: 1.171:15th Gear: 1.085:16th Gear: 0.853:1Final drive: 1st-4th 3.611:1, 5th-6th 3.095:1Differential: Open (F), electronically controlled clutch pack (C), variable torque-type limited slip (R )
ChassisExterior dimensions Curb Weight: 3500 lbs (approx.)Weight Distribution F/R: 60/40Overall Length: 187.6 in.Wheelbase: 105.3 in.Overall Width: 70.1 in.Track F/R: 60.6 in.Height: 56.3 in.
Suspension Front: Upper and lower control arms, anti-roll barRear: One upper and two lower control arms, twist-plate longitudinal link, anti-roll bar
BrakesFront: 13.4-in. vented discs, single-piston sliding calipersRear: 12.6-in. vented discs, single-piston sliding calipers
Wheels And TiresWheels: 18x7-inch aluminumTires: 215/45-18 Bridgestone Potenzas