In addition to its more cost-effective production-based powerplant and heavily revised aerodynamics, other changes from the Z4 GT3 include the elimination of ABS and electronic stability control, both of which are outlawed in GTE, but with the addition of permitted on-board telemetry and the category-mandated air-conditioning system and rear-view camera.

The Z4 GTE's rear end has seen a considerable revision since its first chassis, which rolled out in late January. (Photo: Chris Tedesco/BMW)

While there is no doubt a lot of carryover from the GT3 model, the brakes on the Z4 GTE actually originate from the M3 GT, which has been a proven component through countless endurance races, both at Sebring, Petit Le Mans and also in the 24-hour enduros at Le Mans, Spa and the Nurburgring.

Following months of design proposals, the final build of the car began in earnest less than eight weeks ago, with the Bobby Rahal-led Team RLL crew working hand-in-hand in the assembly process at BMW’s headquarters in Munich.

"I think what has been particularly rewarding about this venture so far is the evolution of our relationship with [BMW] Motorsport, to the point where we cooperated together on much of the design philosophy of the car based on experience we had with the M3,” Rahal says.

“There's been a lot of communication during the design phase, even to the point where our guys are over there building the cars. It's great that there's that level of respect and trust between the two entities.”

The first car, chassis 1301, was completed in late January and took part in an initial shakedown at the Monteblanco circuit in Southern Spain with Dirk and Joerg Mueller handling driving duties. Chassis 1302, featuring some significant aero updates at the rear-end and front fenders, broke cover this week at Daytona.

Incidentally, both of the initial two chassis have also seen time in the wind tunnel, as a test car was not built. A third chassis is currently in production and will be used as a spare.

BMW used the recent test in Spain for a side-by-side comparison of the GT3 and GTE models and received favorable initial reviews.

"I felt at home immediately in the car,” Dirk Mueller says. “It's a BMW, you can recognize that. It's a black and white difference [between the GT3 and GTE versions] because of the regulations but I really enjoyed the car. Definitely, the engineering department at [BMW] Motorsport have done an awesome job.”

While having completed two on-track tests in Spain and a planned U.S. debut next week at Sebring, the Z4 GTE has yet to be fully homologated by the ACO. The French organizers have made four visits in the past six months to review the car. But O’Connell expects the final homologation to come next week.

The other key development for 2013 comes in the form of a new tire partner in Michelin, which will add to the learning curve as the engineers and drivers come to grips of the new package.

"You always hope to get the most out of the car,” O’Connell says. “I think it will be key to really understanding the new car and tires together because it's a tire change for us as well as a chassis change. So I think getting those to work very well will be biggest area of development.

BMW Team RLL will run two Z4 GTEs in the ALMS for drivers Bill Auberlen, Maxime Martin (No. 55) and Dirk Mueller, Joey Hand and John Edwards (No. 56) (Photo: Chris Tedesco/BMW)

“It will be about taking all of our M3 setups and transforming them into a Z4 setup, looking at what's happening to the tire patches and making sure that they have the same kind of behavior, whether it's dampening or geometry or control of the tire on the Z4.

"That's the fun part. After four years, the M3 setup was pretty much dialed in and you had a good handle on it. You could unload at any track and get it out running. The engineers like that challenge. It's going to be good."

Hopes are high heading into the debut season for the car on U.S. soil, although Rahal remain realistic about their chances in the highly competitive GT category in what will undoubtedly be a development year for the newest GTE car on the block.

"There's no question there's going to be tweaking, developing and what have you," he says. But I'm coming into this year with the view towards winning the championship and winning races. And I think everyone else is.

“But it's a new car and there's going to be good days and bad days. It's going to be a development year, inherently, because it's a new car. But that doesn't mean it can't be a good year, either."

John Dagys is SPEED.com’s Sportscar Racing Reporter, focusing on all major domestic and international championships. You can follow him on Twitter @johndagys or email him at