http://www.bmwmregistry.com/model_faq.php?id=12 History
What makes the E34 M5 unique?
The E34 M5 is the BMW Motorsport-developed version of the E34 5 Series. It is powered by the S38 twin-cam 24-valve inline-six, an evolution of the engine used in the E28 M5 and E24 M6. It also has a BMW Motorsport-tuned chassis and a few special cosmetic pieces.
When was the E34 M5 first introduced?
The original E34 M5 was introduced in September, 1988. The later 3.8-liter version first appeared at the 1991 Frankfurt motor show, as did the E34 M5 Touring.
Where was the E34 M5 produced?
Unlike the normal 5 Series, M5s were hand-assembled at the BMW Motorsport facility in Garching, a suburb of Munich. Bodies were pressed at the normal Dingolfing factory, then sent to Garching where they were mated with the engine and interior trim. The only exception was the South African-spec model, assembled at BMW's Rosslyn, South Africa factory from German-supplied Complete Knock Down (CKD) kits.
Production Data
How many versions of the E34 M5 were produced?
The E34 M5 was produced in two distinct versions, each with several variations. Early cars have a 3,535-cc 24-valve inline-6 known as the S38 B36. These M5s were built in both left-hand and right-hand drive configurations, as well as a North American-specification edition. There were also a small amount of 3.6-liter M5s assembled in South Africa, exclusively for that market.
Starting in late 1991, the majority of European-spec M5 production (with the exception of some late 3.6-liter cars built for Japan and the Middle East) switched to a 3.8-liter (3,795cc) version of the S38 (designated S38 B38) and gained Adaptive M Suspension, plus a few cosmetic changes. The 3.8-liter M5s were available in both LHD and RHD variations, but there were no North American or South African editions. However, there was a small production run (891 built) of the E34 M5 Touring, or station wagon, all built to 3.8-liter European specification in left-hand drive.
How many of each version were built?
ECE 3.6 (LHD): 5,877 built from 9/88 thru 4/92
ECE 3.6 (RHD): 524 built from 11/89 thru 11/91
NA 3.6 (LHD): 1,678 built from 12/89 thru 4/93
SA 3.6 (RHD): 265 built from CKD kits 9/90 thru 3/93*
ECE 3.8 (LHD): 2,676 built from 12/91 thru 7/95
ECE 3.8 Touring (LHD): 891 built from 3/92 thru 8/95
ECE 3.8 (RHD): 343 built from 12/91 thru 6/95
*Figures indicate final completion date of vehicles assmebled in Rosslyn, South Africa.
What major revisions were made to the European-spec E34 M5 during its production?
Except for minor trim and equipment variations, there were few revisions to the original European-spec E34 M5 during its production. The first major round of changes occurred with the introduction of the more powerful 3.8-liter M5 in late 1991. Along with the larger engine, the 3.8-liter M5 brought Adaptive M Suspension, a reduced-effort clutch and a myriad of cosmetic alterations. Also, the M5 Touring was added at this time.
The final evolution of the E34 M5 entered production in May of 1994 and included the following upgrades:
-Getrag Type D six-speed manual gearbox
-Enlarged brake rotors with two-piece "floating" front calipers
-Thicker rear anti-roll bars (19mm on sedans, 20mm on Tourings) from the discontinued Nürburgring Package
-EDC mode switch from the discontinued Nürburgring Package
-Staggered 18-inch M Parallel Spoke wheels with 245/45ZR18 tires
-Widened front "kidney" grilles with revised hood to match
Of the 3,910 3.8-liter E34 M5s produced, how many were the later six-speed manual version?
BMW M GmbH produced 752 examples of the later E34 M5 3.8 six-speed, divided among the following configurations:
ECE 3.8 sedan six-speed (LHD): 404 produced
ECE 3.8 Touring six-speed (LHD): 209 produced
ECE 3.8 sedan six-speed (RHD): 139 produced
Drivetrain
How is the S38 engine in the E34 M5 different from the version used in the E28 M5?
The early E34 M5 uses an evolution of the 24-valve inline-six found in the E28 M5 and E24 M635CSi/M6. Despite its official designation of S38 B36, this BMW Motorsport powerplant technically remains a 3.5-liter, with a bore of 93.4mm (same as the previous engine) and a stroke of 86mm (up 2mm on the early S38) for a total capacity of 3535cc (up from 3453cc). The added stroke is due to a new forged steel crankshaft, though the camshafts were also changed. Compression is up slightly (10:1 versus 9.8:1). Further enhancements include:
-An electronically-controlled butterfly valve in the inlet manifold to provide better low-rpm and mid-range power
-Bosch Motronic fuel injection for precise metering of the air/fuel mixture
-Improved flywheel
-Equal length stainless steel headers
-Three way ceramic catalysts (similar to those used on the M70 V12 engine)
The S38 B36 is rated at 315 hp (DIN) or 310 hp (SAE) at 6,900 rpm and 266 lb/ft of torque at 4,750 rpm. Like the earlier S38 B35, it carries the "BMW M Power" inscription on its cam cover but the design of almost every component is different. Also, unlike the engine used in the E28 M5, the S38 B36 engine in the E34 M5 was created to meet all worldwide emission standards from the start. It therefore was equipped with a catalyst as standard equipment in almost all markets, though a special non-catalyst version was produced for South Africa, the Middle East and a few other regions where unleaded fuel was not yet mandatory.
How is the 3.8-liter M5 engine (S38 B38) different from the 3.6-liter version (S38 B36)?
The final evolution of the S38 powerplant, the S38 B38, was introduced in later versions of the European-spec E34 M5. In this application, the bore was increased (to 94.6mm) and the stroke lengthened (to 90mm), raising the displacement to 3,795cc. Though the added capacity makes the S38 B38 the largest six-cylinder production BMW engine of the modern era, it represents only a portion of the major revisions developed by BMW Motorsport at this time. Others include:
-Larger intake and exhaust valves
-Lighter pistons
-Shorter connecting rods
-Increased compression to 10.5:1
-Bosch Motronic 3.3 engine management system
-Distributorless ignition with six coils
-Redesigned intake and exhaust manifolds
-Revised throttle butterfly linked to Motronic engine control
-Dual-mass flywheel with harmonic balancer
-Metal catalysts for reduced backpressure and better heat conduction
The S38 B38 is normally rated at 340 hp (DIN) at 6,900 rpm and 295 lb/ft of torque at 4,750 rpm. However, a cleaner version was developed for Austria and Switzerland, rated at 334 hp (ECE) and later 327 hp (ECE). The S38 B38 can be identified by its grey (instead of black) cam cover surround.
What kind of gearbox does the E34 M5 have?
All M5s built before May of 1994 utilize a Getrag 280/5 five-speed manual gearbox with the following ratios: 3.51 (1), 2.08 (2), 1.35 (3), 1.00 (4), 0.81 (5). This was mated to a 3.91:1 final drive on all five-speed M5s with the exception of North American-spec examples built after July of 1991, which have a taller 3.73:1 final drive for better fuel economy.
In May of 1994, the five-speed transmission was replaced by a Getrag Type D six-speed manual gearbox with the following ratios: 4.23 (1), 2.52 (2), 1.66 (3), 1.22 (4), 1.00 (5), 0.83 (6). It came paired to a taller 3.23:1 final drive.
All E34 M5s have a standard limited slip differential with a maximum locking of 25 percent.
Chassis
How is the suspension of the E34 M5 different from the standard E34 5 Series?
The chassis of the E34 M5 is based on the MacPherson strut/semi-trailing arm design of the normal E34 5 Series but incorporates the following changes:
-20mm reduction in ride height
-25 percent firmer spring rates
-Firmer shock valving all around and self-leveling springs in the rear
-Thicker antiroll bars* (25mm vs. 23mm in the front, 18mm vs. 15mm in the rear)
-Adjustable rear toe-in
*NOTE: M5 Tourings produced before May of 1994 were equipped with a thicker 19mm rear anti-roll bar, also fitted to 3.8-liter M5 sedans equipped with the Nürburgring Package. M5 Tourings equipped with the Nürburgring Package were upgraded to a 20mm rear anti-roll bar. The 19mm rear bar became standard on all M5 sedans produced after May of 1994, at which point the 20mm rear bar became standard on all M5 Tourings.
All 3.8-liter M5s are further fitted with the Adaptive M Suspension, an M-tuned version of the Electronic Damping Control system that was introduced in the E32 7 Series. This system electronically chooses the optimum shock rates based on sensors that gather road speed, steering input, acceleration/deceleration loads and lateral body movements. In addition, five-speed 3.8-liter M5s equipped with the Nürburgring Package and all six-speed E34 M5s have a control switch on the dashboard that allows the Adaptive M Suspension to be locked into its firmest setting during aggressive driving.