Compared to the BMW M3 GT raced in the ALMS over the past few years, the new Z4 GTE is a smaller package, measuring 173.0 inches in length, 79.1 inches in width and 47.4 inches in height on a wheelbase of 98.3 inches. With its steel unibody core from the Regensburg plant where the standard BMW Z4 is manufactured and a complement of carbon-fiber pieces for the hood, fenders and roof, the Z4 GTE weighs 2745 pounds.
Compared to the M3 GT, this new car is much lower yet much wider, so the aerodynamic frontal area is about the same. At the same time, the Z4’s low, narrow greenhouse helps more turbulence-free air to stream onto the rear wing than the M3’s cabin allowed.
The Z4’s relatively flat bodywork also holds out the possibility of optimizing low-speed downforce for the ALMS’s tracks in the U.S., which are generally slower than those in Europe and include street circuits.
Just like the M3 GT, the new car carries a V-8 engine, a 4.4-liter example with a stock block from the BMW foundry at Landshut. The engine makes about 475 hp, revs all the way to 9000 rpm, and runs on E85 gasoline. As the Z4 GTE goes past us, the note from the V-8 also sounds very different than that of the M3 GT. In fact, this BMW sounds like a NASCAR stock car, and NASCAR president Mike Helton smiles approvingly from pitlane where he has come to watch the ceremonies.
It turns out that the rulesmakers proved reluctant to endorse the expensive, free-breathing M3 GT V-8 with its racing-type 180-degree crankshaft, so the Z3 GTE V-8 has a conventional crank layout. The engine not only sounds different but also shakes far less, so fewer parts should rattle off the car. A sonic restrictor in the intake system required by the rulesmakers controls the engine’s power output.
The V-8 is paired with a sequential-shift six-speed manual transmission, and the gearbox is controlled by shift paddles on the steering wheel.