IMSA reveals more LMDh technical regulations

IMSA reveals more LMDh technical regulations


IMSA reveals more LMDh technical regulations


As part of the annual press conference prior to the running of the 24 Hours of Le Mans, IMSA revealed key details of its upcoming LMDh prototype formula. Although most of the technical regulations for LMDh have been finalized, a number of items were either reconfirmed or declared for the first time.

The stated power target for the class is a combined 670hp, with the similar-to-DPi internal combustion engine solutions meant to account for 630hp and the new kinetic energy recovery systems (KERS) from Bosch and Williams Advanced Engineering responsible for 40 electric hp.

A new minimum weight of 2271 lbs has been solidified, which takes the added weight of the KERS units into account. For the sake of comparison, the heaviest DPi at the recent Road Atlanta WeatherTech SportsCar Championship race weighed a minimum of 2083 lbs, or 188 lbs lower than LMDh, in DPi’s non-KERS trim.

Dimension limits for LMDh were also shared, and in a nod towards achieving greater parity between the upcoming LMDhs from chassis suppliers Dallara, Ligier, Multimatic, and ORECA, a standard wheelbase of 3150mm has been established. Maximum length (5100mm) and width (2000mm), and a 4:1 downforce/drag ratio was announced.

Custom bodywork styling options for LMDh have also been increased, with greater allowances for the carryover of road car nose and grille designs, more freedom with sidepod and rear fender shapes, and encouragement for more brand-specific individuality at the rear of the cars.

Suggested pricing for a rolling LMDh chassis (minus internal combustion engine) has been placed in the $1-1.2 million range, with each chassis “spine” expected to cost approximately $410,000. IMSA’s “Hybrid Powertrain System,” comprised of the spec KERS unit and new Xtrac gearbox, could account for up to $350,000. The rest of the necessary items — from electronics to radiators — needed to complete each LMDh bring the total sum to seven figures. Although the current prices vary between Acura, Cadillac and Mazda, a new rolling DPi chassis is said to cost somewhere between $850,000-$900,000.

With the timeline for LMDh expected to be subject to a deferred introduction, the next step for IMSA involves seeking commitments from the auto manufacturers who’ve taken an active role in LMDh’s technical working group.

A dozen or more major brands, including Acura, Audi+Lamborghini+Porsche from the Volkswagen Audi Group, BMW, Cadillac, Ferrari, Ford, Hyundai, Lexus, Mazda, McLaren, and Renault+Nissan are believed to have expressed interest in the formula.