Continental ExtremeContact DW,
Extreme Contact DWS, and Extreme Winter Contact
It's an undisputed fact that your car's tires represent the single most important component in terms of vehicle handling. Upgrading your tires for the type of driving you're aiming to do is the most effective vehicle upgrade you can make. Upgrading tires for dry, warm-weather maximum performance is one thing. But when temperatures and weather conditions start heading south, choosing the right tire for the scenario will still make all the difference in terms of handling, acceleration and braking performance.
When you're talking really cold temperatures, snow, and icy conditions, tire selection becomes even more critical. Continental Tire has a few weapons in its cold-weather arsenal to help you push through whatever adverse environment you may face.
First up are the ExtremeContact DW and ExtremeContact DWS. The DW is Conti's ultra-high performance offering in the all-season category, designed for superior performance in both dry and wet conditions (hence the D and the W), as well as maintaining ride comfort and improved gas mileage. The DWS is designed for performance for both the dry and the wet, as well as in snow (S). Each features chamfered edges and a solid outer shoulder for enhanced performance on dry surfaces, a high void-to-tread ratio and enhanced groove curvature for excellent water evacuation in the wet. There's also what Conti terms "Dynamic Temperature Distribution," which is intended to reduce distortion for enhanced energy delivery, lower rolling resistance and improved tread life.
Speaking of tread life, both the DW and DWS incorporate a feature called Tuned Performance indicators. These are truly useful for the everyday consumer who might not necessarily know when the tire's tread has run the course of its usefulness in certain conditions-namely Dry, Wet and Snow. The indicators are visually apparent letters (you guessed it, D, W and S), stamped into the second rib of the tread, intended to alert the driver of the tire's current optimal performance levels. S indicates the tire is at optimum depth for use in the snow, W indicates suitability for use in the wet, and D indicates suitability for dry conditions. It's a pretty ingenious system that utterly takes the guessing game out of gauging the tire's suitability for whatever road condition that confronts you.
So why offer two variants of the ExtremeContact tire? Doesn't "all-season" mean the rubber is suitable for all road conditions? Definitely not, and we had the chance to see why earlier this year in a particularly frigid and snow-covered remote section of southern Montana. We had the chance to test this new rubber on fairly flat and solid but utterly snow and ice covered driving venues. Naturally we were able to test the Conti rubber against competing products from other manufacturers, and all superfluity aside came away mightily impressed, but we also had the chance to test the DW against the DWS in about an inch of powdered snow. The S in DWS is important. It indicates this tire incorporates one extra feature: special traction grooves and what they call Increased Pattern Edges for improved performance over-wait for it-snow-covered roads. The increase in traction and handling acuity between an all-season tire and a specialty snow tire is actually quite astounding. If you live in an area that's guaranteed to see some sort of snow stick to the ground, the DWS is the tire you're going to want.
The third offering in the lineup, brand-new for the 2009/2010 winter season, is the ExtremeWinterContact. This tire is engineered for use in the most extreme winter conditions, and areas that are guaranteed to not only see sustained weeks or months of snow and ice but also extreme low temperatures. Features include elevated lateral grooves which result in a stiff tread pattern for dry handling, and inclined longitudinal grooves to deliver greater driving force for outstanding traction and braking on snow. Multiple gripping edges contribute to this latter consideration, and the tire is created with a high-tech flexible tread compound and a high sipe density, which work in tandem to deliver reduced braking distances, even on ice.
One other thing about using tires in cold weather-running the proper rubber compound is critical, possibly the best reason of all to select a tire like the ExtremeWinterContact if running in frigid road conditions is an inevitable prospect. You don't want something that's inherently stiff, or something that stiffens up in very low temperatures (like a soft summer tire might). A good winter tire, like the EWC, is contructed with a compound that retains flexibility even in very low temperatures, in order to maintain grip on cold, slippery surfaces-snow, ice, or even cold pavement.
The Continental ExtremContact DW, DWS, and ExtremeWinterContact are available now. -Karl Funke
While most people think of cars being either two- or four-wheel drive, the fact is cars with open differentials are one-wheel drive. Very few cars come with limited-slip differentials. With engine power outputs constantly on the rise, the open diff has become somewhat outdated.
In the past, there weren't too many choices for aftermarket differentials. A specific car will usually only have a few different aftermarket diff makes available. Autotech Sport Tuning in Aliso Viejo, Calif., is about to make the market a little bit bigger. We recently tested out its new Wavetrac differential and came away
Wavetrac uses a combination of helical-cut gears and a unique "wave" coupling, a mechanically expanding center section that prevents loss of drive in unloaded conditions-something no other gear diff has. the wave coupling uses two rings that, in profile, have nesting waves and valleys. When an axle is, or is nearly, unloaded, the center sections turn relative to each other. One ramp climbs the other, pushing the side gears apart and into the housing, causing an axial load inside the diff. This internal load acts for all purposes like the wheel is still gripping, so the diff continues to bias torque to the other wheel instead of losing drive. Other gear-type differentials work in a similar manner up to the point of unloading an axle. Once that happens, the Wavetrac's difference really shines.
It's this central Wavetrac device that allows it to still function in near- or at-zero traction situations. Other gear LSDs will revert to operating as open differentials when there's little or no axle load, meaning that if one wheel is nearly or fully in the air, or the car is transitioning from acceleration to coasting, those other differentials do nothing; they lose drive altogether. The Wavetrac, however, will continue to drive the gripping wheel, even when one axle is unloaded.
Another unique feature is the diff's bias plates, which Autotech has designed for the bearing surfaces inside the differential. The plates allow for consistent operation over the differential's life. Generally, gear-type diffs run their gears in direct contact with the housing. This works well at first, but over time, material transfer and galling from the metal-to-metal contact creates varying friction conditions, which decreases the unit's effectiveness. Wavetracs use a carbon-fiber material designed to last the life of the car, and will perform more consistently since it eliminates metal-to-metal contact. For track use, the Wavetrac's bias ratio can be altered by changing to optional bias plates.
The housings are made from case-hardened steel billet; the internals are built from 9310 alloy steel, which is not only hard but has very good fatigue resistance. The whole thing is held together with legendary ARP hardware.
Our installation began at VW Specialties in Huntington Beach, Calif., with dropping the 02M six-speed transmission from a VW GTI. Transmission teardown and diff installation was performed at Cal Trans in Santa Ana, Calif., and VW Specialties bolted things back together.
Our test car had basic bolt-on upgrades installed that in our estimation pushed output to over 200 hp. An open differential would have spun a tire through second gear, and coming out of turns, it'd spin the inside front even in third gear. With the Wavetrac installed, we couldn't get one wheel to spin even in first in a straight line. But the biggest difference was in cornering. Even on a skid pad the car wouldn't spin a tire. Jabbing the throttle at high steering angles, right at the edge of grip, the inside tire wouldn't let go. If anything, it seemed to bite harder and tighten the cornering line. But the best part is that you barely feel the diff working. Some LSDs are very abrupt, making them tough to drive because they are so aggressive, going from open to bind in a fraction of a second. The Wavetrac works constantly to feed power smoothly to both wheels. Sudden lifts of the throttle still result in forward weight transfer, but you don't get that initial toss from the diff unloading as on traditional LSDs. It's possible to modulate the throttle to keep the car on edge without having to time the diff lock-up.
Wavetrac is currently offered for 10 different applications, including VW and BMW; more are planned. Diffs run between $795 and $1,295. Professional installation is recommended.
Autotech Sport Tuning/Wavetrac
Neuspeed P-Flo Intake
VW and Audi factory airbox/intake assemblies are generally good at muffling operating noise and enhancing low-rpm engine performance, but become very restrictive when the engine is operating in a higher rev range. Neuspeed's famed P-Flo intake is currently available for the latest generation of 2.0-liter TFSI engines. Designed for a simple bolt-on installation, it is engineered to improve both mid-range and top-end power. The P-Flo leaves the MAF and original intake tract unaltered, and It'll also give you a throaty, more aggressive induction roar when you stomp on the gas. Available for carswith and without the O.E. air pump provision. From $299.95
Meguiar's Quik Detailer
If you're a true automotive clean freak, carrying a bottle of spray detailer wherever you go is a given. Meguiar's Quik Detailer is one of our all-time favorites. Now the company offers Ultimate Quik Detailer, formulated with Hydrophobic Polymer Technology to deliver high surface tension that causes water to bead relentlessly-even after washing. Perfect for removing dust and fingerprints, Ultimate Quik Detailer is safe for all paint finishes and will leave your exterior surfaces slick and sleek; just mist and wipe. And as an added bonus, like other Meguiar's products, Quik Detailer smells great. Available at major retailers and specialty automotive outlets.
Wheel of the Month
For each of its applications, SSR uses top-quality materials and precise manufacturing techniques, initiated more than 35 years ago, to create uncompromising high-performance custom wheels. The latest offering is the three-piece Professor SP1, available in a 20-inch diameter and widths ranging from 7 to 10.5 inches for select European automobiles. Available in a variety of finishes including silver, gold, white, black, flat black and "Super Black." From $995
Quicksilver Sport Exhaust
Quicksilver is renowned for creating some of the world's finest sport exhausts. This one, for the 911 GT2 (997), is crafed entirely from titanium and weighs about half that of the OEM unit. Naturally, it is designed to enhance flow and throttle response, as well as a more full and aggressive exhaust note, low and unobtrusive at slower street speeds and increasing in volume and pitch as engine revs increase. The welding techniques are executed precisely, optimizing flow at the central X-pipe to balance exhaust pulses from both cylinder banks for a smoother tone and greater variation in pitch.
Got a car lowered over coilovers and tired of scraping up the driveway or over speed bumps? KW Suspensions offers its Hydraulic Lift System (HLS) for just such a scenario. It's a universal-fit kit engineered for sports cars equipped with coilover suspensions. With it, you're able to retrofit your existing KW coilover configuration, or a similar coilover setup, to provide additional road clearance. A hydraulic cylinder unit is installed between the spring perch and the main spring. When expanded, a range of life from 30 to 45mm is actuated, helping you avoid road clearance issues. The HLS hydraulic pump is installed in or near the spare tire location, while on-the-fly change in ride height is activated remotely by a small keychain transmitter, which also precludes the need to run any additional wiring through the vehicle. Available in two versions: HLS 2, enabling lift at the front axle, and HLS 4, enabling lift at both the front and rear. HLS 2: $3,700; HLS 4: $4,800