Building the Metrik

November 11, 2013
Keith McCrone on track in the new Metrik chassis.

Paul Rieffle and R-Sport built on the debut of their in-house built Metrik chassis during the 2013 F2000 Championship Series, furthering the development of the car. For Rieffle, building his own chassis from scratch was a huge undertaking, but one he had done before, as brothers Jeff and Paul crafted the Gemini Formula F cars of the 1980s.

“Believe it or not we built the first few Gemini’s over the off season in 8 months,” said Rieffle. “That included the casting patterns for uprights, jigs, fixtures, and body mock-up and moulds. All the machining (by hand), tubing work on frames and suspension. The only things we out sourced were front hubs and steering racks.”

How did that make way for the Metrik? Running Van Diemens for customers in the highly competitive F2000 Series, Paul invited Jeff out to the New Jersey Motorsports Park season finale in 2008.

“I approached him about getting involved with building cars again after 25 years. I told him that he probably won’t make any ‘real’ money doing this with me, but wouldn’t spend any money either.  He just said ‘I can’t believe you are going to drag me into this again’ He had wised up quite a long time ago and managed to keep away from racing,” continued Rieffle. “Jeff is one of the best fabricators that I know. He is a wizard at tubing work, sheet metal and welding. He also has a great sense of creativity, that vision that a lot of people lack. Many of the cool features of the car were his ideas.”

Metrik chassis progress

The mission behind the new car was simple – Rieffle wanted a chassis that could finish and eventually win races were there no compromises on safety and reliability, while maximizing rules without crossing any lines. He wanted to address problem areas on existing cars and make his mechanics happy in servicing the car quickly between F2000 sessions.

“The plan was to do everything in house, within reason,” Rieffle noted. “That way we can quickly make changes and adjustments with out waiting for someone else to get things done. That means all design, 3-D modeling/CAD, CAM, CNC Milling and Turning, any manual machining, tubing work, sheet metal fab, welding, composite work, composite molds, jigs, fixtures, casting patterns/core boxes/core prints … everything.”

Rieffle admitted it took him some time to pull the trigger on the project.

“From a business stand point it made absolutely no sense,” he added. “From an adventure stand point, it was inspiring.”

That was in 2008, and the car made its public debut at Summit Point in 2012, to the surprise of many in the F2000 paddock who had no idea it had been in development.

Chassis detail

“We thought it would take two years. It took four. To no big surprise, the estimated cost of the project went wildly out of control, but we held true to our statement that we would use nothing but the highest quality materials. All bodywork, including wing elements, are high grade glass cloth, Nomex or Aluminum honeycomb cored,  epoxy laminated, vacuum bagged and post cured in oven. The side panels and pods are Kevlar as is the driver’s seat. All castings (uprights, cam cover, oil tank) are AZ91 magnesium. All steel and aluminum materials are USA or German.”

The car was an evolution of sketches and drawings Rieffle had done back in 2004, and the first step was to find the support – and funding.

Michael Mazziotti, a former driver for R-Sport, was the first to commit, and asked if the car could fit a driver of his height, 6’4”. Rieffle’s response: “no problem.”

“Drivers Keith McCrone and Tim Dunn, along with a good friend of mine David, saw what was being developed and they also committed to supporting the project. Without their faith and support, the car would never have turned a wheel.”

Among the unique features on the chassis for a F2000 car are a completely stressed engine and gearbox, as the frame ends at the roll hoop.

The engine adapter is also very unique, according to Rieffle.

Engine Adapter Machining

“It starts as a 120 lb 5-inch thick billet of aluminum that is machined down to 12 lbs. It mates the engine to the gearbox, incorporates the clutch slave, holds the starter motor, rear anti roll bar and adjuster, shock mounts, and suspension pick up points. It is doing a lot of work. If the engine package rules change we don’t have to make a new oil tank pattern and casting. We just change the engine side of the adapter.”

The body work has no Dzus fasteners or Camlock fasteners. The engine cover and front shock cover each have a single quick release latch. The team said it can do shock adjustments in less time than most others spend just removing the body panels.

Aside from funding, the biggest challenge of the project for R-Sport was finding the right high-quality materials for the car build.

“We did not want any cheap, substandard, questionable stuff. Suppliers listed materials, but often had long lead times or short supplies on hand,” Rieffle said.

“Aero tubing (for wishbones and pushrods) was available abundantly from China, but we wanted domestic materials. Large quantities of Nomex honeycomb (for all composite bodywork) in expanded form was difficult to get at first. Believe it or not, lead time for the Nomex was between 90 and 120 days.

Metrik Upright

“Aluminum honeycomb for undertrays and diffusers was a little difficult to get in a reasonable time frame as well. Domestic 7075, 2024, and 6061 Aluminum and 4130, 4140 steel with certs also took a bit of shopping. Getting shop help is always a challenge. The joke around here is that everybody not directly associated with the sport thinks ‘we hang out with the coors lite girls and drink beer all day.’”

But R-Sport, among the details lost in the high-tech car, has become a shop were engineers and mechanics can learn something new since everything happens under the one roof.

Rieffle had praise for his suppliers, from Mike at “Lite Metals,” to Hawk making custom brake pads, Brembo finding the right caliper and rotor package. Other s included Doug Learned for the drive axles and C&R for the radiators.

“Other than wheels, tires, shocks, springs, bearings, rod ends, nuts and bolts … everything else is made here. We even make the drive axle boots and retainers. The wing, flap, and small parts molds were all done via CAD and CNC but we had to do the bodywork plug and molds the old fashioned way by hand.”

The car turned its first laps at Nelson Ledges. A track known for its rough surfaces, Rieffle said if anything was going to break or fall off, it was going to happen there.

Two days later, with three different drivers, nothing loosened up or broke. Another test followed at Summit Point, and at that point, the chassis had 800 miles on it and zero issues.

The 2013 season in the F2000 Series, despite loads of track time, did not produce the development atmosphere Rieffle wanted due to an ever changing forecast with most weekends being run in the wet.

“In addition to working on tuning our base mechanical grip platform, we have yet to test the multiple front and rear wing configurations that we have,” Rieffle explained. “Recently we completed a new cockpit and front shock cover design. The vision of shorter drivers was slightly and momentarily impaired during transitions through switch back areas of the track. The original cockpit design enclosed the steering wheel. The new design exposes the steering wheel area of the cockpit opening and is slightly lower at the dash hoop. Both cockpit designs are easily interchanged with no modifications to any other components.”

While the original plan was to keep the cars fully in-house, available for rent through R-Sport, Rieffle said that may be changing. For 2014, R-Sport plans to continue campaigning its Metrik chassis, but he  realizes that it may be time to open up and get other people, teams, and investors involved.

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