Technical Article |
By James Williams
Racer/Technician
Advantage BMW
Appearing soon at a BMW dealership near you, the new Z3 is the first new drop-top two place BMW seen on these shores in many years. Bigger than a Miata, smaller than a Mercedes-Benz SL, this little sports car has the muscular good looks of soul-stirring proportions. Fathered by BMW Technik, this car is a direct descendant of the spy photo darling of a few years back, the Z1.
The major styling cue of the Z1 was doors that lowered downward into the sills rather than opening outward. Neat stuff indeed, but real world drawbacks were high entry and exit stepover and side impact integrity was questionable.
The Z3 is creating some fuss of its own, even before the official debut. In the new James Bond movie Golden Eye, 007 will be motoring about in a Z3 instead of an Austin Martin or Lotus. The English haven't been in such a snit since the last movie where James was driving a Lincoln Continental. Machine guns, bullet-proof shields, smoke screens and ejection seats are nowhere to be found on the options list. Bummer.
When they get here, this is what you can expect; The convertible top is hand operated and lowers into a boot between the seats and the trunk, which is the same size as the luggage area on the 318ti. When lowered, the top is covered by a rubber cover instead of a metal lid like current convertibles. The unibody and attending systems are pure E36, while the outer skin has its own look. The covered headlights have a more aggressive look and the twin kidney grills are in a section of the hood, much like the E38 740I. Sixteen inch wheels with Z-rated 225/60 R16 tires add to the muscular look.
Front suspension is a strut mounted to a single control arm, while the rear suspension is lifted directly from the 318ti, which was lifted directly from our friend, the E30. Brakes are disc front and rear with Teves Mark IV ABS looking over your shoulder to keep you safe and sound.
Under the hood resides the new M44 engine. 100ccs larger than its sibling, the M42 currently in the 318i/iS/ti, horse power stays at 138 ft. lbs. The peak of this torque curve is also lowered slightly from 4500rpm to 4300rpm, widening the power band and boosting mid-range performance. Displacement was increased by both a larger bore and a longer stroke. The double overhead cams are driven by a double row chain and rubber covered sprockets to keep maintenance and noise down. Four valves per cylinder are kept to proper clearance by hydraulic lifters, and the valves are the same diameter as the M42, 33mm intakes and 30.5mm exhaust.
Helping the engine breath is an intake manifold with a moving vale inside the plenum that changes the intake runner length with engine rpm. This helps optimize the torque curve and is controlled by manifold vacuum and the Motronic. Crankcase ventilation is now routed to a new valve mounted on the intake manifold, much like the M60 V8s. Idle control is no longer handled by a valve and hoses, but is now an electric valve mounted to the side of the throttle housing. No more split hoses to leak.
Exhaust gasses are led away from the head by a welded stainless steel manifold to a new catalytic converter with two oxygen sensors; one before and after the cat. The converter is also bigger for increased flow.
I don't know about you, but I can't wait to get my hands on one and zip it around the block a few times. This is going to be a great looking car and, I like the "shake grills" in the front fenders. And if the M44 doesn't have enough beans for your tastes, later in the production, BMW has said it will come with the new 2.8 litre, next generation M50 six cylinder. I bet this is the one Mr. Bond drives, but maybe not at home in England.