Bob Riley On His Riley Mk.XlV

Russell Wittenberg spent some time with Bob Riley at the recent Watkins Glen Grand Am meeting – discussing the new Riley LMP car. “We learn so much so fast that the only really interesting car is the next one," says the President of Riley Technologies (on the www.rileyscott.com website).

After Bill Riley and I finished discussing the DP and tomorrow’s Watkins Glen race, I asked if we could review the new Le Mans Prototype. Both Max Angelelli and Wayne Taylor had already checked in during our conversation - to let Bill know they were ready to talk race strategy for tomorrow’s event. Not wanting to ignore his drivers any longer, Bill suggested that I really should to talk with his father, Bob Riley, about the LMP as Bob has been exclusively handling the design work for it. No sooner did the words leave his mouth, than the trailer door behind me flew open and in came the elder Riley, seeking air conditioned relief from the heat wave that besieged upstate New York that weekend. Bill expressed my interest in the LMP to Bob and then excused himself to tend to his anxious drivers. The elder Riley gladly took over the conversation, and over the next hour, methodically described his latest design from front to rear. I was quite content to listen and learn, as I was taken on an interesting and educational tour around the new American prototype sportscar.

“Experience in this business is invaluable. You do look at previous designs to get a baseline and ideas, but also to avoid things that didn’t work. But when doing a new design you want a reach, or something new and unique to this particular design. For this project we actually had pictures of nearly all prototypes over the last few years cut out and pasted on a board. So you are always looking for ideas and things you might be able to use. The Bentley is obviously the most recent and successful closed top car and that in particular gave us a clue on how big to make the roll hoop/cockpit area.

“I would do a sketch and Travis Jacobsen transfers them to the CAD. The released drawing is the actual design from our CAD and shows the car in Le Mans trim.

“The nose is raised because the rules require a higher impact point for the crash structure. The brake ducts were located in the nose in lieu of the traditional position in the front panels, between the nose and wheel arch. This placement should benefit from the positive pressure here, but should not adversely affect the downforce.

“By rule the center of the splitter must also be raised. The air that will collect under this part of the splitter needs a way out, so we have it exiting behind the front wheels, through louver vents in the sidepods.

“We have designed in a shelf along the bottom edge of the sidepods; this should get a little positive pressure to help when the car is in yaw. The ridge or shelf continues up the leading edge of the rear wheel arch, and should help with some downforce.

“The vent at the top of nose and center of windshield is for driver cooling. Again the base of the windshield is a point of positive pressure.

“The design shape for the roof of the cockpit is actually an airfoil. Basically we took a section through an aircraft wing, and rotated it length wise to fit the shape of the car.

“Carbon fiber will be wholly used in the construction of the tub. It’s really the only option to maintain the low weight and meet the new crash standards. For instance, the impact load that the roof or roll structure must withstand is 17,000 lbs. The impact area is located across the roof, right in front of the driver’s head. 17,000 lbs. is an incredibly high number to achieve, so the load must be dispersed from the roll structure down through the side pods and tub. It would take a lot of heavy steel to meet that load requirement.

“The engine exhaust is center of the rear deck, at the end of the roof pod, for two reasons. As the car moves it directs the air around each side of the cockpit. This creates a vacuum or empty space right behind the cockpit, over the rear deck. That vacuum negatively affects the air that is flowing past the cockpit. The engine exhaust here should help to fill that void, making the airflow cleaner and denser, creating downforce on the rear deck without increasing the drag. Locating the engine exhaust there also keeps from having to route the exhaust pipes around the rear wheel suspension. This will keep unwanted heat from the pipes away from the suspension and makes this area easier to work on.

“We have designed the rear deck as low as possible for less drag. Once again this drawing represents Le Mans configuration, so for a track like Mid-Ohio we would add a flap across the back to generate more down force.

"For this design we decided to bring the rear wheel arches to a point in the back, in an effort to reduce drag and direct air to the sides of the arch. Air over the top of the arch creates lift, which is not good. The end plates are regulated by rule to a minimum size and we elected not to connect them to the wheel arch, allowing air to tuck in between and flow through. At higher downforce tracks, we could have a revised rear deck in which the endplates do connect.

“One feature that wasn’t released in rendering form was a view of the rear. We still have some details to work out around the taillights and back of the car (the drawing was available for viewing for this meeting). The new rules have set a specific design for the undertray and length of rear overhang. This rule should help the smaller manufacturers like us. The undertray is an area in the past where the larger budget manufacturers have spent a lot of money to gain an advantage.

“We are pretty far along with the design and have already been talking with the people at Langley about doing the CFD work. This would be the next step and it will help us locate some vents, possibly on the rear deck, for the engine bay, and the size and placement of the wheel arch vents. Following the CFD work the design would be finalized and ready for production.

“We will also probably do a ¼” scale model, to review the bodywork to make sure it’s smooth and fits properly. Also it is desirable to have a model for the customer to see. Although we have found that scale models don’t represent the car properly in the wind tunnel and that the CFD work does a better job of that.

“With this car we will use the best possible parts right from the start: sometimes in the past we were not able to do that.

“We have had a lot of interest in the car so far. Obviously we would like to sell some to customers of course, but we are also looking to find a sponsor or a partner so that we can run a car ourselves. We want to win Le Mans overall, and that’s the bottom line.”

For teams looking towards competing at Le Mans, or either of the Le Mans based series, in 2006, the Riley Mk.XIV must be seriously considered. We just witnessed an American team win the famed race: could it be an American-made prototype that claims the prize next year?