Growing at both ends: Spartan Motors unveils new RV chassis with 525 hp engine, as well as entry-level model

Diesel Progress North American Edition, April, 2004 by Dawn M. Geske

Spartan Chassis Inc., a subsidiary, of Spartan Motors Inc., Charlotte, Mich., has expanded its diesel RV chassis line with the addition of new models at both ends of its product line. The new K3 chassis offers the highest gross vehicle weight rating (gvwr) of the company's RV lineup, while the Competitor chassis adds an entry-level diesel chassis engineered to compete with the gasoline engine chassis.

"The buyers of high-end motorhomes are demanding more features and options from their RVs than ever before, which adds weight and extreme performance demands," said Richard Schalter, president of Spartan Chassis. In response, the K3 chassis offers a rear-mounted, dual overhead cam, liquid-cooled Cummins ISX diesel engine rated 525 hp at 1200 rpm. The engine includes a Holset variable geometry turbocharger, which is designed to provide quicker throttle response and faster vehicle acceleration, the company said.

Cooling is through a side-mounted AKG cooling system and additional engine accessories include a Leece-Neville 270A alternator, Sanden air conditioning compressor and 5 in. NGI gauges.

The K3 chassis is equipped with a six-speed Allison 4000 MH automatic transmission with a frame-mounted miter box steering gear. Input torque for the transmission is 1850 lb.ft. and towing capacity of the chassis is 15,000 lb.

The rear of the chassis incorporates an ArvinMeritor axle with Wabco ABS brakes and a Ridewell 246 suspension system. In front are Dana Kirkstall IFS84 steer axles with Knorr Brehmse air disc brakes. Michelin 315/80R XZA1 LRL fires are used all around. Gvwr is 36,000 to 37,300 lb. or 50,000 to 51,300 lb. with the installation of a 13,600 lb. capacity tag axle.

A truss design is used in the raised flame of the K3 chassis consisting of a web of steel frame rails in both the front and rear, along with a number of sub-structural support beams. Tubes are used in the center and rear drop of the chassis. The high gvwr and sound structural design allows OEMs to expand the RV body beyond the chassis footprint, adding additional living space to the interior, the company said.

The K3 chassis is scheduled to enter production in the second quarter of this year.

At the other end of the spectrum, the Competitor chassis, as the name suggests, incorporates an economical design intended to compete with high end gasoline motorhomes. A commercial drivetrain is used to narrow the price gap between diesel and gasoline RV products, the company said. Production of the Competitor is anticipated to follow in the third quarter of 2004.

The Competitor chassis is driven by the same engine used in Ford's F150 pickup trucks, a rear-mounted 6 L, liquid-cooled Ford Powerstroke V8, diesel engine rated 325 hp at 3300 rpm. The engine, built for Ford by International, generates 550 lb.ft, of torque and is cooled by a Valeo cooling system. Accessories include a Visteon alternator and air compressor.

The engine is teamed with a five-speed Ford TorqShift automatic transmission along with a ZF variable ratio hydraulic assist steering system. The chassis has a 25,000 to 25,750 lb. gvwr and features an ArvinMeritor RS15120 rear axle. Detroit Steel Products Stabil-Ride suspension systems rated 9000 lb. and 15,000 lb. respectively, are used in the front and rear and four-wheel hydraulic disc brakes are standard. The Competitor chassis features a standard straight frame or optional raised frame and towing capacity is 4000 lb.

Spartan Chassis has high hopes for both new units, according to CEO John Sztykiel. "The fastest growing segment is 500 hp and above motor-homes," he noted. "The K3 specifically targets this trend and we expect it to be the standard bearer for OEMS and end users."

He added that the Competitor chassis "will help pave the way for more entry-level products in the diesel pusher market by lowering the cost to OEMs--and RV end users--and offering them a viable, more comparable choice between gas and diesel-powered engines."

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