VAC Motorsports M2

VAC Motorsports M2 -

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By Klaus Schnitzer
Photography by Klaus Schnitzer

The Ultimate Vintage Sleeper
Beneath the innocuous skin of this beautifully restored 2002 beats the heart of a raging beast in the form of an S14 engine transplant by VAC Motorsports.
By Klaus Schnitzer
Photography by Klaus Schnitzer

For the ultimate vintage sleeper, nothing beats a 2002 with a powerful S14 engine under the hood. Quite a few of these 2002/M3 hybrids are roaming the roads of North America, but few can match this VAC Motorsports special for low-key appeal. To start with, it’s not even one of the coveted round taillight models, but one of the later square-taillight examples—a big-bumper 1974 model, to be precise.

For its owner, that only adds to the attraction. After all, it’s what’s inside this car that counts: As good as it looks from the outside, it’s even better when examined at close range, where VAC’s total modernization plan can be fully appreciated.

Best of all is the view from the driver’s seat, which gives its occupant the chance to enjoy simply stunning performance in an understated package. It’s a fine expression of the German Tiefstapler concept—the one that piles it low and plays it cool instead of heaping it high and extroverted.

Adapting old to new
At the heart of this remarkable restoration is an S14 four-cylinder engine sourced from an E30 M3. Its original 2.3-liter displacement has been increased to 2.5 liters via VAC’s stroker crank kit, which increases stroke by 2.4mm (from 93.4mm to 95.8mm) and bore by 1mm (from 84mm to 85mm). The kit uses Arrow Precision H Beam connecting rods, manufactured in England and sold through VAC Motorsports, to reduce reciprocating weight from the stock 629 grams to 546 grams. Four CP forged pistons, which are custom-made for VAC in California, provide a compression ratio of 11:1. A VAC Stage III ported and polished cylinder head uses a set of cams with a 276° VAC regrind, plus PSI valve springs that are slightly stiffer than S14 EVO springs.

A VAC oil pump kit upgrades the stock unit with a new oil pump shaft that has been machined with a key drive, an internally threaded shaft (5/16-inch left-hand thread), a new key-driven oil pump sprocket and a Grade 8 bolt. As VAC Motorsports’ Tony Salloum explains, “This kit prevents the very common failures associated with the factory oil pumps: nut loosening, stripped nut, stripped splines, the nut and threads shearing off the face of the factory shaft or the nut with threads and splines shearing off the shaft.”

The oil pan required modification for better baffling and to allow the drain-back of motor oil from the factory oil separator located on the side of the S14 block. “This, by the way, led to the nice VAC/Moroso hybrid oil pan that is designed for use in any 2002 or 320i with an S14 or M10 engine,” Salloum says.

A Sachs S14 heavy-duty clutch and S14 flywheel transfer power to a 320i five-speed overdrive transmission modified to accept the factory crank sensors. The transmission connects to a 3.91 rear end via a shortened driveshaft made in-house by VAC’s machine shop.

As you might expect, VAC put a lot of development and attention to detail into making the various parts work together within the 2002 chassis. The boxed engine mounts took one day to fabricate and install, and more fabrication was required to fit the S14’s ECU to the underside of the 2002 glovebox—the 2002 didn’t have an ECU, as it used a mechanical injection system.

Making the 2002 accelerator linkage work with the S14 throttle also took a bit of effort. “We wanted to use the factory 2002 pedal assembly and also keep the factory E30 M3 accelerator cable without modification so future replacement would be painless,” Salloum says. “We were able to accomplish this by fabricating an adaptor that attached between the factory pedal and the original S14 cable along with a mounting bracket for the cable to attach to the engine. It was time-consuming, but it came out flawless.”

Fuel gets to the cylinders via EVO-spec injectors, which flow about 20% more fuel than stock U.S.-spec S14 injectors, and ported and polished 48mm throttle bodies with stainless steel throttle plates. Intake air is filtered by a K&N cone filter upstream of the factory air mass meter.

Reliable spark is ensured by a VAC/Moroso performance ignition wire set. This wire set uses Beru ends to eliminate the problem of a faulty connection at the spark plug that was common with the Magnecor wire sets used as stock on the S14.

For engine cooling, VAC uses a stock 2002 copper-core radiator with a modified 320i thermostat. During our test drive, the car ran somewhat hot, prompting immediate surgery that resulted in the installation of a larger electric fan. After this change was made, the car was driven to Texas without any problems.

Chassis and cosmetics

As well as upgrading the engine bay, VAC Motorsports treated the 2002 to a cosmetic rejuvenation that included new paint, restuffed and reupholstered seats.

VAC also modernized the car with an E30 air conditioning system running on R134 refrigerant. The latter was easier said than done: VAC needed to use the original S14 compressor, but the 2002’s existing lines and receiver drier weren’t compatible with it. That forced VAC to lay out a completely new system, locating the new receiver drier behind the grille while still leaving room for the air conditioning fan. VAC also had to have all-new air conditioning lines made to link the old evaporator and the new components.

The chassis also received a major makeover. At the rear, VAC retained the stock 2002 drum brakes and fitted Porterfield R4S shoes, but at the front, the company installed the vented rotors from a 1977 320i clamped by Wilwood Superlite four-piston calipers. Of course, all are connected with VAC’s custom-made stainless steel brake lines.

VAC used Bilstein Sport shocks and Eibach springs to lower the car by one inch and take care of bump absorption. Salloum likes the Bilstein/Eibach combination for its high quality and reasonable price. “We feel that Eibach is still the leader in spring technology,” he says.
Body roll was reduced via a Suspension Techniques front anti-roll bar that measures 21mm in diameter—fully 5 mm larger than stock—mated with a stock rear bar. Urethane bushings are used throughout the chassis, which rolls on 195/60 R-15 Pirelli P700Z tires mounted on 7 x 15-inch ACT wheels.

Vintage 2002 meets M3

Enough on the specs. Let’s take this old-timer for a ride. From the driver’s seat, everything is vintage 2002—basic, solid and very manual. With its baritone exhaust and shaking shift lever, however, the non-stock provenance of this car is obvious, and the throttle response confirms it.

From a standstill, the machine explodes forward, then delivers an even greater dose of momentum when the motor hits its stride past 4,500 rpm. With approximately 260 flywheel hp at 7,000 rpm, this stock-looking 2002 can accelerate from zero to 60 mph in the high 5-second range and should run the quarter mile in around 13 seconds. The power is addictive, even as it requires a certain amount of practice to keep the axle from hopping under hard acceleration, a typical trait of big-power 2002s.

Firm brakes quickly rein in the power when it’s time for drama-free deceleration, and threshold moderation is easy thanks to the excellent pedal feel. The ride, as one would expect from the Bilstein/Eibach suspension package, is solid and well-controlled. It’s somewhat harsh on the streets of Philadelphia, but you should see those streets! Overall, the setup should provide a perfectly livable balance between the demands of street use and track schools.

With a total lack of electronic nannies, including ABS, one has to exercise a certain amount of restraint—not to mention car control—when trying to determine the car’s full potential. There’s no power steering, either, so a bit of effort is required when parking. The payoff is feel at speed, although the ratio remains somewhat slow. We’d prefer the rare close-ratio steering box, but then we don’t have to worry about parallel parking this ‘02.

Salloum estimates that it took about 300 hours of labor and somewhere between $40,000 and $50,000 to complete the project. That’s a lot for even a restored 2002, but the car’s owner is happy. “He wanted a vehicle that would look original while being a real sleeper from a performance standpoint, basically the devil in disguise,” Salloum says. “He was so ecstatic with the 2002 that he has us working on another project, this time a 1972 3.0CS that’s getting the works.”

Salloum is also happy with the result, though he doesn’t consider it a good job from the financial side. “I guess when you’re passionate about what you do, you’ll make the same mistake over and over again!”

© 2007 Nick Vyse.