Usually an automotive journalist or a staff editor would be writing the article on the annual Alpine demo vehicle. This year Ben Oh was kind enough to ask me to give readers the inside scoop on the Imprint RLS. My name is Gary Bell and I am an R&D application engineer for Alpine Electronics of America. Last year there were just two of us, myself and the world famous Steve Brown, when we built the Sinister Six. This year we added Brent Davison to our team. Brent comes to us from Texas and was in top running for a 2005 installer of the year award. You may remember the Cavalier he built not long ago. Without a third member on the team it might have been next to impossible to finish the vehicle you see here in the less than four months we had to rebuild this Mercedes.
Concept
A project like the Imprint RLS starts to take shape one year in advance, at least the conceptual aspect. The first night of the 2006 CES show (the debut of the Sinister Six) Steve and I started throwing out a bunch of ideas. Maybe that was because of the lack of sleep while completing a torturous build, or the excitement of revealing a new car, but in reality it was probably the gallons of Rockstar energy drink still flowing in our veins. Although nothing was written down, or even sketched on a napkin that night, one thing was for sure: We had to outdo ourselves.
We had some rough ideas by the time got home from CES, but the first real decision was made on April 20th. This was the day that TIS wheels and Pirelli tires announced that they were introducing a 30" wheel and tire. We knew we had to use them on the new demo car, so we were on the phone minutes later. Now we just needed a car with huge wheel wells and the real brainstorming could begin. After looking at literally hundreds of cars, we narrowed it down to two. The Mercedes Benz R500 and the CLS550. We loved the bodylines of the CLS. We adored the huge presence (and wheelwells) of the R500 and its 300hp engine. We soon realized that the ultimate would be a combination of the two. A CLS-inspired SUV. Some quick sketches from Ryan Roybal of Roybal Designs got the team excited, and off we went. On September 1st a stock R500 pulled into the bay. What happened next would make most Mercedes mechanics and engineers cringe.
Project Start
The first step was to dismantle the car. Every part of the car that wasn't needed was pulled off and packaged for storage. This included the doors, hood, fenders, bumpers and rear hatch. All of the factory electronics were relocated to the front of the car, and new battery trays were welded into the front interior quarter panels. The factory steering shaft was relocated to the center of the car using 3/4" hardened shaft, u-joints and carrier bearings. The gas and brake pedals were relocated and attached to our new dual gas and brake assembly. These modifications allow the car to be driven from either seat. To give the car an aggressive stance, the rear inner-fenders were removed and replaced with larger wheel tubs. The original air ride system was replaced with new Parker valves and a Viair compressor.
Starting with a stripped, but drivable shell, the B-pillars were removed and the rocker panels reinforced. This made room for the massive motorized seat/door assembly. The guys over at TIS loaned us some 26" and 30" rims and tires. After bolting on the new wheels and doing a little trimming of the factory rear quarter-panels, the huge CNC plasma-cut wheel arches were attached to the car using the MIG welder. Over the next two weeks the body was carefully framed out using 3/16" cold-rolled steel rod. The result was reminiscent of a 3-D wire frame model.
Motoring
Like the last few Alpine cars, we wanted unconventional door and seat mechanisms. Using large 12" diameter bearings, a unique rotating assembly allows the suicide doors to swing into the vehicle with the seat attached. Each door uses a DC TENV motor to drive a gear reduction box. The gear reduction box turns a gear that connects with a brass gear track attached to a large aluminum plate that is bolted to the bearing assembly. Got all that?
The doors and seats are not the only motorized part of this ride. The amprack motorization makes the doors look simple! The original concept was to have the amps "slide" out of the back of the car. After a quick review we decided that was too easy! The new vision was to have the amprack rotate as it slid out the back of the vehicle. The compound movement was created using only one motor!