More than a week of input from Daytona Prototype entrants on the draft Prototype regulations has resulted in a number of expected revisions, culminating in IMSA competition and technical regulation VP Scot Elkins distributing a second version to the paddock.
Based off the input received from those planning on contesting the TUDOR United SportsCar Championship next season, many of the areas that would have allowed for vast expenditures have been narrowed to discourage budgets from skyrocketing.
Some items will remain open for revision until the November tests at Daytona and Sebring give Elkins and his technical staff a chance to benchmark and adjust the various Prototype entries as they deem necessary.
Confirmed Prototype Regulations:
1: Only one new and noteworthy concern has emerged from the V2 rules. One-piece forged wheels, standard items in P1 and P2, were a newly permitted DP option in V1, which led most teams to plan on buying the lighter units. But allowance has been revised in V2, which the required use of the 2013-spec three-piece wheels at the rear. One- or three-piece wheels are allowed at the front of the car. With as much as 60 percent additional downforce expected to come from the updated DP aero kit — most of which is generated at the back of the car and loaded across the rear axle — a safety concern has been raised by at least one team about the risk of wheel failure due to design tolerances being exceeded. A resolution could be included in V3.
2: A significant row over the costs involved with converting to and using carbon brakes has been met with a compromise. Based on V1, any team that did not switch to carbon brakes would suffer a significant performance disadvantage, but V2 reveals a 25-pound penalty for any team that uses carbon — something that's been done to allow those wishing to remain with steel discs to minimize the performance loss. Another adjustment has been made within the carbon disc specs with a 380mm diameter allowance in V1 being revised to the more conventional 380mm front and 355mm rear disc diameter in V2. Per V1, teams could have tried to fit the bigger carbon discs at the rear, which would have been a costly development item. Another note, specifying only one six-piston caliper is allowed per front wheel, is a change from V1 where only a single six-piston caliper was permitted on all four corners.
3: Limitations on the number of permissible gear sets has been removed.
4: IMSA further defined the style of differentials allowed in the DP class, eliminating viscous differentials, which essentially leaves the existing, mechanical diffs as the primary option to continue using in competition.
5: As Elkins shared in an interview with RACER over the weekend, an amendment on the brand of dampers, model types and total amount of low-speed and high-speed compression and rebound adjustments (four) have been added to V2.
6: A typo in V1 of the draft regulations stated the maximum capacity for turbocharged and supercharged gasoline engines was 3.4 liters, which has been corrected to reflect the correct capacity of Ford's 3.5-liter V6 EcoBoost turbo and any other 3.5-liter turbo or supercharged V6s that may appear.
7: An item that concerned teams in V1 — the allowance of ceramic suspension and wheel bearings, which could have become a costly development item — has been removed from V2.
Possible Upcoming Changes:
1: With DPs lacking overall downforce, the use of tall, body-mounted rear spoilers were used to extract air from the engine bay, beneath the car and to generate downforce. The new high-downforce aero kit, with its rear downforce bias, could render the angled pieces of aluminum a thing of the past. The decision on whether the NASCAR-esque downforce generators will remain part of the fourth-generation DPs will be made after the November tests.
2: The fairly simple, straight-out-the-back DP exhausts are also up for revision. With the introduction of turbocharged engines to the class for 2014, not to mention tall, wide diffusers taking up a lot of real estate, IMSA will specify exhaust routing and termination.