2003 Suzuki LTZ400

2003 Suzuki LTZ400 QuadSport Possibly The Best Sport ATV this Year!

    Suzuki’s sport ATV venture started in 1984 with the introduction of the first QuadSport LT230S. The 230 QuadSport encountered huge success and proved there was a market in the Sport ATV segment. Soon after the QuadSports introduction, in 1989 the original 230 QuadSport was replaced with a larger 250 QuadSport, which ran production until 1991. Other units included the QuadRacer 250 and 500 models, these units ran threw the 80s into the early ninety’s. The QuadRacer models where by far ahead of their time when high performance ATVs were just coming about. Since then, Suzuki “first on four wheels” has been lying dormant. The last QuadRacer models were produced in 1990, Public liability and government regulations put an end to Suzuki’s sport quad evolution. That is until now, The sleeping giant is back. Suzuki finally decided enough was enough, they knew if their engineers put a sport unit together it would be a winner. A sure winner, the new LTZ 400 was born a homerun with the first proto-type. Engineers and test riders worked to improve the Z400, testing the unit and perfecting the unit took several years. We talked with some of Suzuki’s test riders and engineers, seems the original proto-type was just what Suzuki targeted. Over the few years before introducing the Z400, the new unit was constantly trying to be improved on. Each time designers tried an improvement. The original design was found to be better than the improvement. Surprising even themselves, the original proto-type Z400 need little change. Sure small changes were made, but the basic concept Z400 remained unchanged.

Engine:

    The features of the QuadSport Z400 engine might sound familiar since it is based on the well-proven DR-Z400 Suzuki motorcycle powerplant. The QuadSport Z uses Liquid Cooling to maintain optimum engine operating temperature and minimize power loss due to engine heat. Liquid Cooling is especially effective on racing-type engines that operate at consistently high RPM. Radiator placement on the QuadSport-Z was chosen for it excellent cooling abilities. Radiator placement along with the Dry Sump lubrication system allows for optimum engine and radiator placement to keep a low center of gravity. The 398cc engine delivers a flat torque curve and a strong response range from 3,000rpm to 8,000rpm. The engine is composed of an aluminum-alloy, (*note- Suzuki�s own race-proven nickel-phosphorus-silicon-carbide coating known as SCEM.) oversquare, 90.0×62.6mm, four-stroke, liquid-cooled, DOHC single-cylinder with four valves actuated by cam lobes riding directly on bucket tappets. The cylinder head features a narrow, 28 degree included valve angle for a compact, efficient combustion chamber, with an 11.3:1 compression ratio. This narrowed valve angle allows the use of a straighter intake tract between the 36mm Mikuni carburetor and the cylinder head, which in turn improves charging efficiency. The valves themselves are relatively large, 36mm intakes and 29mm exhausts, all with 5mm stems to improve port flow. The valve springs have aluminum-alloy retainers that are more compact and lighter than conventional valve springs and steel retainers. The aluminum alloy cylinder reduces weight and improves heat transfer, allowing tighter, more efficient piston-to-cylinder clearance. A counterbalance shaft reduces vibration, while an automatic cam chain tensioner and electric CDI ignition system simplify routine maintenance. Placing theengine lower in the frame because of a slightly angled cylinder head and dry-sump lubrication system makes for a compact design. We loved the surprising amount of power generated by the 400 engine, throttle response we very receptive. Our test of the Z400 included some winding wooded trails with plenty of ruts and small logs, we also encountered miles of scenic fire roads. The quad is as light as it looks, weighing just 168 kilograms (370 pounds) dry. The LTZ400 excelled no matter what the terrain characteristics were but we sure did enjoy an aggressive ride on any of the many fire roads. The engines power carried threw the complete RPM range which topped out at around 8,000RPMs. We spent some time talking with Suzuki representatives about the engines future, we asked questions like how strong is the bottom end? Does the engine have enough durability to be modified? The answers we received were all positive and we�re sure your going to see some very trick modified versions of the 400 powerplant in the near future. Suzuki has already introduced a complete set of exhaust systems to increase engine performance. A quick change to one of the Suzuki supplied, Yoshimura exhaust systems can up the horsepower considerably.

Transmission / Five-Speed-and-Reverse

    The QuadSport Z400 features a manual clutch and a five-speed manual transmission with reverse gear. On the right front fender a knob was mounted, this is where the rider would release the reverse interlock to allow the shift pedal to be used to select reverse gear. Actual ride time is always the best way to discover just how well a transmission fits the rider. For example, will the sifting process be smooth? Will the foot shifting pattern be spaced close or will the foot shifting lever need to move extensively in order to shift gears. Well rest assure, the Z400 has the best matched power to transmission operation we�ve tested in sometime! Final drive is via an O-ring-sealed chain. Suzuki�s own start-in-gear system allows the engine to be started in any gear with the left clutch lever applied, which is pretty typical of any standard shifting model.

Chassis/Suspension

    The chassis features a lightweight, rigid, high-tensile steel-alloy tube frame and subframe. The suspension is impressive giving the rider confidence when catching air or hopping over fallen logs on the trails. Independent double-wishbone front suspension with preload-adjustable coil-cover shocks delivers 210mm (8.3inches) of wheel travel. The aluminum-alloy swingarm rear suspension system features a single, fully-adjustable piggyback-reservoir shock and produces 231mm (9.1 inches) of wheel travel. The Adjustable Preload feature gives the rider the ability to apply more tension to the spring if the ride feels too soft or less tension if the ride feels stiff. The Adjustable Damping feature lets the rider fine tune the suspension for the surface and/or a better ride. Damping helps regulate the speed that the shock springs compress and extend. When you adjust the compression and rebound damping you are actually adjusting the oil flow through the shock. More compression damping will slow the compression of the shock and more rebound damping will slow the rebound (extension) of the shock. Wheelbase is 1,245mm (49.0 inches) with 262mm (10.3 inches) of ground clearance. Standard equipment includes a tube-steel front bumper and high-impact-plastic skid plate. The skid plate is lighter than conventional skid plates, eliminating corrosion, dents and slides easily over terrain high spots. The double, serrated steel footpegs are vented for maximum grip and reduces mud build-up. If your looking for maximum traction and performance the QuadSport Z400 comes completely equipped with standard aluminum-alloy wheels, 10.0 x 5.50-inch front and 9.0 x 8.00-inch rear, carrying Dunlop AT 22 x 7 x-10 front radials and AT 20 x 10-9 rear radials. You get stop on a dime braking action with the hydraulic disc brakes featured all around, the dual discs are up front and a single disc in the rear. The convenient parking brake allows the rear brake to be set using the left handlebar lever.

Bottom Line: 

   If you’re attracted to an aggressive look and sporty styling wait until you find out the Quad Sport Z has the same MSRP as the Honda 400EX and with many additional advantages including Liquid Cooling and Reverse. The QuadSport is 0.00-0.00 less expensive than the Yamaha Raptor.     The seat height is set at 810mm (31.2 inches) giving a smooth transition between the seat and bodywork. The twin air intakes-positioned just inboard of each front fender-direct more air to the radiator. The fuel tank holds 10-liters (2.65-gallon) and weighs 1.3 kilograms (2.9 pounds) giving the rider hours of recreation before needing to refill. Standing still you can easily see the aerodynamic technology that went into this sporty design. Bottom line, get out and enjoy yourself whether you are surfing the sand dunes or tackling some woodsy trails this ATV was definitely engineered and intended for FUN.