January 1999 by Barry Winfield
Four-door convertibles are extinct, right? Wrong.
Newport Convertible Engineering will chop the top off just about anything.
Al Zadeh’s long-running affair with convertibles began nearly 20 years ago. While at the University of Southern California pursuing a Petroleum-engineering degree, Zadeh’s personal cars were always convertibles. Now he runs his own conversion company, Newport Convertible Engineering, in Placentia, California, where he lops the metal tops off anything you care to bring him.
Take this BMW 740iL, for example. It’s a long-wheelbase car with four doors, and the German automaker did not design it to go topless, but neither the car’s Floridian owner nor Al Zadeh let that stop them. And now, $22,000 and innumerable worker-hours later, the Bimmer wears a new toupee – a power top.
Cutting the roof off any sedan severely compromises its rigidity. To brace the 740iL’s unibody, NCE welds a maze of two-by-two-inch square-section hollow tubing underneath the floorpan. Tubes run the length of the rocker sills – laterally from one rocker to the other and diagonally from the ends of the rockers to the center. The reinforcements reduce ground clearance by an inch or so, but they look strong.
Two-by-one-inch tubes extend vertically to the highest point in the cowl structure in front and to the shock towers in the rear, tying these to the underbody frame. Finally, Zadeh adds a “trunk bridge” – a tubular arch running between the mainframe members. It’s visible in the trunk, but it intrudes minimally on luggage space.
Removing the roof produces other problems. The 740iL’s door glass runs in window frames. Cutting the frames off would leave the windows unsupported, but leaving the window frames in their entirety would look extremely dorky. So NCE removes just the upper rail of the front window frame and everything but the B-pillar upright on the rear window frame.
When the doors are shut, with the top either up or down, this arrangement looks okay. Open a front door and you’re treated to the peculiar sight of two frame uprights ending in grommeted stumps. It isn’t particularly stylish.
A “basket handle” hoop runs over the car between the B-pillars, providing a brace for the body, a support for the top, and a handy place to fit a dome light and two map-reading lights. Sawing off the roof (and rear window) also removes the integrated radio antenna, so the BMW now wears a conventional mast antenna mounted in the rear quarter-panel.
Rear-seat space suffers, too, in this conversion. The articulating top structure and the hydraulic rams consume so much space that the outboard bolsters of the bucketed seats are completely removed. Occupants are therefore displaced inboard where they must ride a hump. We think a more artful solution would have been to remove the center armrest and squeeze the two bucket seats together.
With its top up, the BMW has a profile similar to that of the stock sedan, although the C-pillar area is now huge and the plastic rear window is smaller than the original backlight. The windshield header has a one-inch channel to accept the top’s leading edge. It is clipped in place by two overcentering clamps and fits flush. This helps cut noise and top lift, both of which seemed quite tolerable during a brief test drive.
In fact, the BMW retains a lot of the composure and tranquility it had when it wore a steel top. The folded top stacks up about six to eight inches above the trunk, but the snap-on boot covers it tidily. On the move, the car exhibits some cowl shake over bumps, but no more than most factory convertibles do. The only question remaining is how well the car will hold together over time.
Zadeh is confident. He does a lot of conversions- about 65 in ’97, including a Lincoln Mark VIII, a Mercedes S-class and an E-class coupe, and a Lexus LS400. He hoped to finish off ’98 with 100. From body reinforcement through mechanism design and fabrication to canvas top-making tasks, every aspect of the work is handled in-house by Zadeh’s 15-member team.
Our BMW went directly from the showroom to NCE with fewer than100 miles on it. For its owner, that’s almost like buying a new, factory-made convertible. To us, it seems like a remarkable leap of faith.