Teams in the American Le Mans Series and Grand-Am's Rolex Series continue to beg for two critical pieces of information to help finalize their planning and budgeting efforts for 2014.
With the announcement of the 2014 United SportsCar Racing calendar now expected to come next week – the week of the combined ALMS and WEC event at Circuit of The Americas – at the earliest, an end to the ongoing frustration regarding the USCR schedule could be on the horizon. The same could be true for the series' technical regulations, and specifically, for the Prototype class.
Bits and pieces regarding the rules for the combined ALMS P2 and Grand-Am Daytona Prototype class have emerged in recent months. The move to a spec Continental tire has served as the most significant change to date, but the unfinished work on the aerodynamic, mechanical and power upgrades for the DP cars is the area causing the most amount of stress for DP entrants.
Scot Elkins, the man tasked with establishing parity between the P2 and DP cars, sat down with RACER at Monterey to provide an update on the progress being made for the USCR's Prototype regulations, and started by addressing the aero changes coming for DP.
“The aerodynamics are pretty close to being locked in,” he said. “The timetable's always been the same. It's always been September-October. We'll take all of the results from the CFD and the sims and make some real parts, then validate that in a [wind] tunnel. And then once we have that validation, we'll take those parts and go do some testing on the track. We're on version three of the diffuser. We're supposed to get feedback [this week] for that.
“Hopefully, once we get that feedback and then once we lock down the design, we can start making parts. The rear wing is pretty much done. It's just the diffuser – we need to finalize that. Finalize that design, once that's done, make parts, put time in the tunnel, go to the tunnel, and just keep chipping away at it as we can. So we could have on-track stuff happening at the end of the month, ideally October.”
DP teams have been expecting two primary aero updates for next year: a new rear wing – a move from a single element with a narrow chord to a brand-new dual element design – and a proper diffuser to extract air from beneath the car.
By moving to a matched aero solution at the back of the DPs, a decent increase in downforce will be generated, and after a recent test by the Spirit of Daytona DP team that included new venturi tunnels built into the sidepods (and a one-off dual element wing using the current profile), Elkins has expanded the 2014 DP bodywork updates to include three items.
“What we took from that test is we actually added the tunnel structure that [SDR] came up with to our diffuser and have incorporated that,” he added. “I sent that to all the constructors on Friday. So we pulled that piece from what they did and added it to what we we're doing already. It actually helped. And it's good because where it's located it helps, it actually shifts the center of pressure forward, which means we have less aero changes needed to the front.”
On its own, and with its greater presence in the topside airstream, the new rear wing would also reduce top speeds, but with the added downforce coming from the tunnels and diffuser, DP teams will be able to use the bottom of the car to generate significant downforce. Those aero tuning options should also allow the DP cars to draw closer to their P2 counterparts in the corners while bringing the DPs down to a top speed that's closer to what the high-downforce P2 cars can achieve.
“It's really less drag and it allows us to control the center pressure better than making most of the downforce on the topside, so it helps a ton,” Elkins continued. “And the aero changes are going to do a lot to make the cars more similar in how they make their speed. Having them both on the same tires is also going to help a lot. We're exploring traction control for the DP cars as well which will help the raceability a lot. It's not going to be perfect, but we're looking at all the options.
“The way we see it right now it, there'll be a group of tracks where we'll have things pretty close, and there will be some where getting the DPs and P2s closer will take a little bit of work. But for the DPs, we think the raceability's probably going to be pretty good because we're adding 60 percent more downforce to what it has now. That's a lot. It's high, but we're not starting out with a lot to begin with, and that changes the raceability quite a bit.”
Working from the current DP downforce min/max range of approximately 1700/2400 lbs, the 60 percent jump would move DPs up to a 2700/3850 min/max, which is at least within the vicinity of the figures produced by HPD's class-leading P2 chassis.
Rumors regarding a change in brake packages for P2s and DPs have been making the rounds lately, with P2 cars supposedly moving from carbon to steel, and DPs from steel to carbon, but at present, RACER has confirmed the cars will continue in 2014 with their current solutions in place. Horsepower for the DPs, however, will indeed be on the rise to compensate for the extra weight the tubeframe cars carry.
“It's about 10 to 12 percent up on power,” Elkins noted, which should move DPs from the 550hp range to slightly north of 600. “The power change is more about the weight difference between the cars; we have a 300-lb difference between the P2 and the DP. So we're adding downforce to a heavier car, but the power is more about the weight and to equal that out, as opposed to offsetting the new downforce.”
“All of the engine builders have known what our target was going to be for the last five months, and they've all been working toward that target with sonic restrictors. All of the power and aero developments are currently happening at the same time.”
With DP teams making the majority of the changes to level the playing field in Prototype, the costs involved with those upgrades is the last major question needing an answer.
One area of expense that's hard to define at this stage is the number of new mechanical components that could be needed to handle the big spike in downforce. Although the DP cars are incredibly robust, it's possible some of the design tolerances on suspension components and mounting points could be reached or exceeded as increased cornering and braking loads are fed through the chassis.
Opinions have differed on the anticipated price for all of the necessary 2014 DP pieces, with estimates ranging from $100,000 to nearly $200,000 per chassis. Teams have been told to expect a $50,000 price tag for the aero items, which could keep the overall update figure below six figures.
“The manufacturers and teams have been aware of this and have expected there to be some mechanical updates to go along with the new body pieces,” said Elkins. “Until we have every item done with the aero, people can speculate what the parts are going to cost, but we've been able to control the costs pretty well. And thinking about cost for us has always been at the forefront for us from the very beginning of this project.
“We've always said we don't want to change external surfaces; we want to have multiple parts that can be added onto the existing body. We want to maintain the philosophy that we've always had with the DP which was trying to keep everything at a reasonable cost.”