JDC-Miller to Run Porsche 963 in 2025 Spec With IMSA Provision

Photo: Brandon Badraoui/IMSA

JDC-Miller Motorsports will run its Porsche 963 in 2025 specification this year, following approval by IMSA that now allows GTP class cars homologated prior to the 2026 season to participate in the WeatherTech SportsCar Championship at the sanctioning body’s discretion.

Sportscar365 has confirmed that the Minnesota-based team, which ran its LMDh car in 2025 spec in last November’s IMSA-sanctioned test at Daytona International Raceway, requested not to purchase Porsche’s extensive aero update kit that has resulted in the 963 taking it fourth Evo joker ahead of the 2026 season.

Both of the factory Porsche Penske Motorsport entries debuted the new aero at the test, alongside new-look LMDh cars from BMW and Cadillac as well as a minor update for the Acura ARX-06.

It comes after all LMDh and LMH-based prototypes re-visited the Windshear wind tunnel late last year for re-certifications.

The comprehensive updates to the 963, which includes a new front splitter design, rear deck and diffuser package as well as other changes to the bodywork, is understood to cost somewhere in the six-figure range in USD/Euros, which has been deemed cost-prohibitive for JDC-Miller according to team principal John Church, who fields the lone-remaining privateer entry in the top class of either the WeatherTech Championship or FIA World Endurance Championship.

Up until now, the LMDh technical regulations, governed by IMSA and the ACO, mandated that any approved Evo jokers had to be deployed to all cars competing in either or both championships.

However, IMSA has now opened the door for an exception to be made.

“We’ve been approved and that’s how we’ll run, in Petit [Le Mans] 2025 homologation,” Church told Sportscar365.

“It’s really the only way it’s going to work for us at this point. I approached [IMSA] a while back and asked. Porsche did as well. This is something that was discussed in the summer in Europe as a possibility.

“It went kind of quiet [for a while] but it’s our plan. It’s the only way it keeps us on the grid.”

The provision was confirmed in a technical bulletin sent to teams on Monday afternoon, which states the sanctioning body “in its sole discretion may permit” a GTP car homologated prior to the 2026 season to participate in the series.

“Any such car must comply, in its entirety, with the applicable homologation form and the most recent LMDh technical regulations under which the car was originally homologated,” the bulletin reads.

“The homologation specification applicable to such car shall be considered frozen and not be partially or selectively updated.

“Notwithstanding the above, IMSA may, at its sole discretion, require a car homologated prior to the 2026 season to comply with specific provisions of the 2026 LMDh technical regulations, as expressly designated by IMSA.

“Any such requirement shall be strictly limited to the provisions explicitly identified by IMSA and not be interpreted as permitting the selective adoption of 2026-homologated components, specifications, systems, or configurations beyond those expressly
mandated.”

The bulletin further states that a move from one homologation specification to another is permitted only with “express IMSA approval and be implemented in full when the car is entered for the applicable event and subsequently the remainder of the season.”

The bulletin adds: “IMSA reserves the right, at any time, to approve such participation and to determine compliance, eligibility, and conformity with all applicable technical regulations, homologation forms, and technical bulletins.”

Church indicated that his 2025-spec Porsche will run to the same Balance of Performance as the factory Porsche Penske entries.

He added they have no plans to switch to the 2026-spec over the course of the season, owing to the costs involved.

John Dagys

John Dagys is the founder and Editor-in-Chief of Sportscar365. Dagys spent eight years as a motorsports correspondent for FOXSports.com and SPEED Channel and has contributed to numerous other motorsports publications worldwide. Contact John