First technical details of Hypercar/LMDh rule convergence revealed

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First technical details of Hypercar/LMDh rule convergence revealed


First technical details of Hypercar/LMDh rule convergence revealed


The long-awaited information needed to shape the future of sports racing prototypes has been delivered to auto manufacturers and specialist constructors interested in the FIA WEC’s Hypercar formula, and those with an eye on IMSA’s LMDh category.

RACER has learned both next-generation rule sets, which were meant to be unveiled in March at the combined IMSA and WEC SuperSebring event, have been distributed, and with the regulations in hand, the finer aspects of the Hypercar and LMDh formulas have been defined.

It’s believed the biggest areas of commonality between the WEC’s inventive Hypercars and IMSA’s LMP2-based LMDhs has been found in an overall reduction in horsepower and a higher minimum weight.

Rumors in recent months during the regulatory convergence process suggested a significant obstacle to clear, as a divide between the high-power desires for Hypercars and the medium-power needs for LMDh manufacturers posed a budgetary conflict. Something in the range of 785hp was targeted for the Hypercars, which have options to run with or without kinetic energy recovery systems (KERS), and was presented as the standard for both formulas to meet. But the majority of interested Hypercar and LMDh manufacturers are known to have pushed back at the figure.

While reaching almost 800hp would have been easier on the Hypercar front due to the greater latitude with internal combustion engine (ICE) designs, considerable cost would have been involved. And on the IMSA side, where DPis make just over 600hp in their current non-hybrid form, manufacturers pressed to keep the same general output number in place, which would allow the carryover of those DPi ICE powerplants in the new LMDh formula and save a substantial amount of money.

Had the Hypercar power peak been adopted, all-new, purebred racing engines would have been required in LMDh and jeopardized manufacturer participation due to the spike in budgets. Unlike the WEC’s top prototype class, IMSA’s DPis have both GT3-based engines and custom engine solutions; at 785hp, all of the GT3-derived motors would need to be shelved.

The new peak power figure is said to be 670hp for Hypercar and LMDh, with IMSA’s new and spec KERS units providing enough power to reach the new number without requiring extra power from the ICE.

A minimum weight of 1030 kilos, or 2271 pounds has also been agreed upon across both formulas, which is higher than expected, and likely accounts for the various powertrain and KERS combinations in Hypercar.

More details on aerodynamics and other facets of the converged prototype formulas are also known to have been shared with manufacturers.