2000 import tech roundup

Motor, Dec 1999 by Weissler, Paul

High technology starts making its way into lower volume vehicles as the Asian and European manufacturers gear up for the new millennium.

Who says all the newest designs are trucks and SUVs? Sure, there are plenty of them, but the highest technology still is primarily on the car side, and the import nameplates have a lot to show for the new millennium. This technology involves more than wading through OBD II powertrain diagnostics. The impact can also be felt on what used to be the low-tech jobs-the ones you could trust to a lightly trained beginner. Because of emissions control warranties, many of these formerly low-tech jobs are the first ones independent shops will see.

Some of the highest (and least forgiving) technology first appears on lower volume cars. So you'll get a chance to enter it into your "cranial hard drive" before the high-volume models appear. But don't count on that opportunity-- the top sellers are adding technology to build sales appeal. And something you'll see first on a low-volume model may hit high production before the model year is out, the engineering changes are moving that fast.

Here's a look at some of this technology, as offered by the Asian and European manufacturers.

Audi

The Audi TT sports car obviously is a styling winner, in the mold of the New Beetle (the same design team did it, using a modified VW platform). And when you see the transverse four-cylinder under the hood, you might think it's a rebadged VW with new sheet metal. However, the TT is a high-performance vehicle, with the existing Audi 20-valve turbocharged/intercooled 1.8-liter engine turned east-west, and redesigned to produce 180 hp. That's a 30-hp (20%) increase from last year, and there's a 225-hp turbo (with twin intercoolers) coming next year.

The '00 engine actually has a new shorter block, which allows shorter, stiffer connecting rods, to help the engine perform at the higher power level. As part of the redesign (similar to what was done on the VW 2.0-liter four for ,99), the intermediate shaft and sprocket were eliminated. The water pump is now integrated into and directly mounted to the block, and is driven by the toothed side of the timing belt. The coolant thermostat housing also is integrated into the block. All these changes make the block more compact and rigid.

Like the other VW/Audi engines, the 1.8 now uses extended-life organic acid (OAT) antifreeze, which you can identify by its pink color.

The transverse powertrain uses torque-axis mounting, which was pioneered by General Motors to smooth out the idle. Instead of a top-engine "dogbone" to control torque reactions, Audi has a bottom-engine "pendulum" bar to do the same job.

The powertrain electronics include drive-by-wire and a new camshaft sensor for faster starts. The old sensor had a single Hall window; and it took 2% engine revolutions for the computer to get the fuel and ignition ready for the right cylinder. The new sensor has four slots (two Aide, two narrow), so the engine can start in just over a single rev.

Audi still calls its all-wheel-drive system the Quattro, because it's become a "brand" name after all these years. But the TF all-wheel-drive system transfer case actually is not the long-used torque-sensing, all-mechanical design. Instead, it's a "Haldex coupling," a design almost everyone else has been using. It's an electronically controlled multidisc hydraulic clutch linked to the vehicle's Central Area Network data bus, and mounted to the front of the rear differential. Why the change? The Haldex permits a computer-controlled duty-cycle-regulated torque transfer of up to nearly 95% to the front or rear wheels, compared with about 66% for the all-mechanical type.

The front and rear suspensions on front-drive Tr models are strut designs, with a torsion beam axle in the rear. If you have to remove a front strut, be ready to spread the pinchbolt housing. There's a special spreader socket, of course, but you should have some old spreader socket you can grind down, if necessary to fit in.

The rear suspension on Quattro models is totally different from the front-drives. The Quattro type is a duallink trailing arm design with a subframe and sway bar, with short coil springs and separate shocks mounted at a 450 angle. This helps provide a very spacious trunk for a sporty car.

In the rear suspension of both frontdrive and Quattro models, the trailing arm bushings are a specific design that works with angled mounts to allow controlled self-steering in hard turns and stop it after the turn is completed. When you replace the bushings, be sure to align the markings with the mounting brackets or vehicle handling will be affected. If you have to remove the rear wheel bearings for service, replace them with new ones. And tighten the bearing nut torque to spec-it's critical.

Honda

The Honda S2000 rear-drive sports car is a big step up from the Mazda Miata. It comes in at around $30,000-by today's standards a fair price for a hightech, high-performance convertible. It has such high-tech features as electric-- assist power steering and an Audi-like torque-sensing all-mechanical rear differential, so it raises a number of unHonda-like service issues.