E39 M5

European Car Magazine

When the honeymoon is over and the time calls for lasting love, personality is everything. That’s what I’m told, as I’ve not yet reached that point in life, but it’s true that my best friends do not stay that way because of their looks or bank accounts.

A similar situation can be true with cars. Several years ago, a mid-engine sports car was redesigned. The normally aspirated version of the new car races in the same SCCA classes as the old car and is more competitive, but many street drivers prefer the older car because it is smaller, 300-lb lighter and pulls exuberantly to a 7500-rpm redline while the new car is reluctant to reach its 6300-rpm limit.

Among the joys of driving are many besides pure speed. I spent hours trying to make sense of the Race Marque Systems-built 528i you see here. Fortified with a 319-bhp 34-bter M3-based stroker motor, its relative deficit in low-end torque prevents it from being faster than a 540i Sport. Obviously I thought, just buying a 540 would have saved a lot of trouble, but then I realized that speed, while this car has plenty of it, is really not the point. “Pleasure” is its answer to the question of “why?”

The car’s owner, a beltway-based lobbyist, brought the car to Osh Minelian of Race Marque Systems with another tuner’s supercharger on the 2.8-liter engine and a request to make it better, a charge that was completed thoroughly, inside and out.

Though RMS has its own line of supercharger systems, the owner felt that increased displacement would lead to better results. Osh started with a 3.2-liter M3 engine and added a custom crankshaft, connecting rods and pistons, resulting in a bore of 87mm and a 95mm stroke. Cylinder-head flow was increased commensurately with 1mm larger intake valves and 0.5mm larger exhaust valves. Some port work was done, and RMS cams were installed. An RMS header was bolted on and an RMS M3 exhaust system was modified to fit the E39 chassis. Custom software was done in-house to ensure that the benefits of the hardware changes were maximized. The final results were 319 bhp at 6500 rpm and 292 lb-ft at 5000 rpm. The
engine was just the beginning of the drivetrain changes, though. A lightweight (11-lh) steel flywheel was used, with a sport clutch providing 1,200 lb of clamping force The six-speed transmission from a European M3 provided ratios very close to the stock five-speed, with the addition of a 0.82:1 overdrive on top. An RMS short shifter was optional, but the custom transmission cross member and driveshaft were required to make the longer tranny fit. The final drive benefited from a Quaile automatic torque biasing differential and a change of ratio from 3.15:1 to 3.46:1, improving acceleration while still allowing sixth gear to reduce cruise rpm by 11 percent. 

With such radical acceleration hardware, the brakes couldn’t be left stock. RMS assembled AP Racing parts to come up with a “too-much-is-just-enough” combination: 13-tn. rotors squeezed by six-piston calipers in front and 12.4-in, rotors gripped by two pistons each in the rear. Osh reported no problems getting the larger calipers to work with the stock ABS hardware. 

Large wheels were required. to clear those pizza-sized rotors. Fikse FMI5 forged three-piece wheels were used by the IMSA Supercar series champion in more than one year, so RMS deemed them good enough for this ear. Plus, in S.5x17-in, sizes, wrapped with 245/45ZR17 Michelin XGT P4 tires all around, they look pretty cool. 

The suspension that RMS’ client eventually chose is unusual for a ear with a drive-train like this. As a first go-round, H&R Sport springs were paired with Koni adjustable dampers, but the owners desire for comfort combined with poor road faces in his part of the country made combination unacceptable. He event found the factory BMW Sport suspention offered just the right combination of comfort and performance to suit his taste. 

The car’s exterior was enhanced in a understated way with color-matched Schnitzer lips all around. They’re not factory parts, but they look like they could be in spite of all the preceding technology this most outstanding—and certainly most unusual—feature may be its into designed in-house by RMS. First galning approval as a computer rendering, the to or is based on the factory luxury seats: maximum comfort. The bolsters were built up to support the occupants during enthusiastic driving, and the headrests reshaped to match. New covers had sewn, so the opportunity was taken to perforated chestnut leather in the center inserts, as well as for the shift knob and emergency brake handle and arm rests, a final touch on a very special, individual

Of all the changes made to this car, buying a 540i Sport to begin with would have covered only the engine, transmission, drive and suspension. The sharp-tool wheels, enormous brakes and plush lot or would still be lacking. 

And then there’s the personality—in this case, the heart of a diva. A great class musician once placed Jaguars at Le Mans among his favorite sounds, and we has agree. Their song is shared by most Is sporting straight sixes. High compression gives it sharpness, and large cylinders fill the bass. Vintage Trans Am cars bellow with the wrath of God, but angels sing in sixes. With a lightweight flywheel and a short throw shifter, conducting their chorus should be all the more rewarding. The owner of this car is to be envied, for that is his task every morning and evening. He a unique and special car. It is by no means an M5 killer, but certainly there are reasons to argue for it against a 540i. Cars like~ don’t come along very often.