Written by Per Schroeder
From the Oct. 2004 issue
Posted in Shop Work
Unless you’re into experimental industrial music, you probably wouldn’t want to listen to a violin concerto next to a busy freeway. It just wouldn’t sound very good. You need the proper location to enjoy the sweet music that a violin can make—a quiet concert hall, for example.
Most things in life work best in the appropriate environment, where strengths are played to and weaknesses minimized. Cars are no exception.
BMW lauds their automotive offerings as the Ultimate Driving Machines. Certainly a stock car from the company is a pretty well-rounded street machine that will work at just about any autocross. But once the speeds increase and the limits of high-speed handling are discovered on a real race track, any production car’s weaknesses can be found. As a result, the car can feel out of its element. Most cars are a little soft, a little heavy and a little down on power, no matter if they’re a BMW, a Chevy or a Porsche.
Despite being an ultra-sporty version of their normal 3 Series, BMW’s M3 model is no different. It’s got too much body roll and is way too heavy for proper club racing use. But with a little tweaking and re-engineering, the already-potent M3 can become a real terror on the track.
Since 1986, there have been three generations of the M3; to learn more about each type, we visited Sebring for the Porsche BMW Owners Club Winterfest race. There we would drive, watch and compare the three as they did their dance at speed. It was a good excuse to get out of the office for a few hours, and Sebring in late January is beautiful.
We also polled some of the top names in the BMW performance tuning world to get their expert opinions. Will Turner of Turner Motorsport, James Clay of Bimmerworld, Bob Tunnell of Bimmer Haus Performance and Jay Mauney of RTR Motorsportz came up with a host of recommendations and opinions on each of the three cars.
BMW’s M, or Motorsport, is a unique operation. As a wholly owned subsidiary of BMW, Motorsport supports private BMW racing teams, conducts factory racing programs and creates high-performance components for BMWs. But Motorsport’s most visible products these days are its line of special high-performance M-designated BMWs.
The first car released with an M badge was the M1 in 1979, but the M story starts nearly 10 years earlier. BMW Motorsport GmbH, formed in 1972 and headed by Jochen Neerspach, was set up to guide and aid BMW’s motorsports effort around the globe.
The first project was to turn the BMW CSL coupe into a winner in the European Touring Car Championship. Ford had been atop this series in the early ’70s with their Capris, but by 1973 the CSL, an M-modified, lighter version of the 3.0CS coupe, began dominating the ETCC. BMW won that championship from 1973 through 1979.
The CSL, or “Batmobile” as it came to be known because of its then-radical wings, also came to the U.S. In IMSA competition, the CSL won the Sebring 12-hour race in 1975 and the 24 Hours of Daytona in 1976.
After this feat, BMW Motorsport switched gears and started developing tuned versions of BMW’s production sedans. Starting with the BMW 5 Series, the M Company was formed to build pseudo-factory hotrods out of many of BMW’s most popular cars. The legendary M535i, M5 and M635CSi were built throughout the ’80s, while the non-production-based M1 supercar was also produced until the early ’80s.
In 1986, these first four models were joined by the four-cylinder, E30-chassis BMW M3. (This car didn’t come to the U.S. until 1988.) The original plan was to build 5000 of these two-door sports sedans, enough to satisfy the homologation requirements for European touring car racing, but total sales finally amounted to almost 18,000 units. It was the success of this original M3 that made BMW Motorsport GmbH a serious player in the performance-car market.
E30 M3: The M Car for Boy Racers
While the first three BMW M cars were designed as ultimate high-performance luxury cruisers, the M3 had only one purpose: to get around a race track quickly. Naturally, this made the E30-chassis M3 very popular with true enthusiasts.
Introduced to this country in 1988 and based on the then-current two-door 3 Series coupe, the M3 wore an almost entirely new skin. It featured unique front and rear fenders, doors, rocker panels, rear roof section, trunk lid, deep front spoiler and a wing over its higher trunk lid. Body-colored deformable plastic bumpers, almost no chrome, lowered suspension and wide sports tires further differentiated it from the more pedestrian 3 Series models.
The M3 looked serious from the outside, but things got even more impressive underneath its muscular body. Its front suspension was all-new and built to race car standards. Beefy two-piece forged steering knuckles with five wheel bolts provided strength and lightness at this critical connection between suspension and wheels. For strong steering feel, there was three times the caster of the production 3 Series suspension; this effect was enhanced by a quicker steering ratio and power steering that was revalved for more feel.
The front anti-roll bar was linked to the struts instead of the lower suspension arms, making the bar more effective. In addition, the rear anti-roll bar was larger than the one used on the standard 3 Series cars, while front and rear tracks were wider. Twin-tube gas-pressure shock absorbers were fitted all around, and the whole suspension system was set almost an inch lower than the 325i’s.
The M3’s brakes were downright huge for a car of its 2800-pound weight: 11.0 inches at the front and 11.2 inches at the rear. As in other BMWs, ABS was standard. The wheels were BBS cross-spoke cast alloys, sized 15x7 inches, and carried 205/55VR15 tires.
Designated S14 by BMW Motorsport, the M3’s engine could be interpreted two ways: as a four-cylinder version of the S38 engine that powered the M6 and M5 (with which it shared bore and stroke), or as a road-going version of the BMW Formula 1 engine that won the Grand Prix World Championship in 1983.
Either way, this was a race engine tamed for the road. Its cylinder head had chain-driven, twin overhead camshafts, four valves per cylinder and precision-machined intake and exhaust ports. Individual throttles for each cylinder ensured not only maximum power, but also clean exhaust and reasonable fuel economy. The compression ratio was 10.5:1.
Tuned intake pipes and a new ML-3 Digital Motor Electronics engine-management system supplied the engine its air, fuel and ignition. The dual exhaust system was racing-style too, with a welded tubular header feeding into a twin-path, low-restriction catalytic converter. Cylinders were honed smooth to allow reliable operation at up to 7250 rpm, with the oil pan baffled to prevent foaming at such high revs.
Like the ports, the classic racing-type hemispherical combustion chambers were precisely machined. The crankshaft had eight counterweights, versus the four of the typical four-cylinder engine, for the balance that was critical at very high engine speeds.
All this racing technology led to some very tangible results, including an output of 192 horsepower reached at 6750 rpm—truly impressive for a 2.3-liter engine of its day.
The M3 was only available with a five-speed manual transmission and a 4.10:1 limited-slip differential; so equipped, it could accelerate to 60 mph in 7.6 seconds and reach a top speed of 143 mph.
The car’s race-bred engine gives it something of a Jekyll/Hyde personality. At low rpm ranges, it seems a little pokey. On crowded city streets, the car is somewhat harsh and buzzy. However, let the M3 loose on back roads, an autocross course or a race track, and you will see the true Mr. Hyde emerge. Up toward the limit, the power almost feels like there is a Formula 1 engine under the hood.
The chassis is so well balanced in even stock form that it can turn most any driver into a veritable Hans Stuck behind the wheel. If one does make a mistake, the big 5 Series brakes will solve the problem without complaint.
In other countries, the E30 M3 was not the top doggy of the E30 range. Rather, the M3 Sport Evolution appeared with more aggressive spoilers, tricker interiors and even more horsepower. The E30 M3 Sport Evolution III had a production run of some 600 and sported a 2.5-liter engine that produced 238 horsepower.
E36 M3: More Is Definitely More
We were along for the ride when BMW introduced the E36-chassis M3 to the press in the spring of 1995, and instantly became fans. Other members of the press felt the same way, and the awards and accolades quickly started to pour in. Checkered flags soon followed.
With the earlier E30 M3, BMW had basically built a race car for the streets. They softened their approach a bit for the E36 M3, instead offering a more highly tuned version of the already-impressive 325is. BMW released this second-generation M3 as a 1995 model.
Unlike the E30 version, the E36 M3 used the same block and head as the standard six-cylinder 325is. Increasing the bore by 10.8mm and the stroke by 2mm gave the new M3 three liters of displacement, a boost over the 2.5 liters found in the appropriately named 325is. BMW Motorsport also enhanced the flow characteristics of the 325’s cross-flow, four-valve head. The M3 featured different camshafts, with more lift to meet the needs of the massaged cylinder head.
Thanks to these modifications, the 1995 M3 produced 240 horsepower at 6000 rpm and 225 lb.-ft. of torque at 4250 rpm. By comparison, the standard 325is offered 189 horsepower at 5900 rpm and 181 lb.-ft. of torque at 4200 rpm. The E36 M3 could scat from zero to 60 in about 6.1 seconds and was electronically governed to 137 mph.
An even hotter engine, featuring individual throttle bodies for each cylinder, was available in European and Canadian markets, but unfortunately not here in the U.S.
Distinguishing the new M3 from the rest of the lineup were a subtle air dam and modified rear apron. Underneath, the transmission mounting points, drive shaft central bearing mounting area and differential carrier mounting areas were reinforced. Firmer springs, thicker anti-roll bars and firmer gas-charged struts helped the handling, and the front geometry was modified to improve steering characteristics. To keep the car under control, the larger brake rotors and calipers from the M5 were fitted: 12.4-inch rotors up front and 12.3 inches in back. All were vented. Seventeen-inch wheels were needed to clear the large rotors.
Unlike the previous generation, the E36 M3 saw some changes during its U.S. model run. In 1996, displacement was increased to 3.2 liters; the following year, a four-door M3 was offered. A convertible joined the lineup for the 1998 model year.
When all was said and done, the 1994-’99 BMW M3 finished with a total production of 71,279 coupes, sedans and convertibles.
E46 M3: Is More Better?
When we published our first full road test of the new generation M3 in our December 2000 issue, we concluded that with a 333-horsepower, inline six-cylinder engine and zero-to-60 times in the 4.8-second range, this car has a lot to offer.
The styling for this M3 is based on the latest E46-chassis 3 Series coupe, introduced to U.S. buyers as a 2000 model. As we mentioned in the February 2000 issue of GRM, the latest 3 Series coupe is a good bit ahead of its predecessor in the comfort, refinement and styling departments. So, by default, the current generation M3 should be better in these areas than earlier examples.
The look of the E46 M3 slots right between BMW’s two previous incarnations of the car. Some people complained that the E36-chassis M3 didn’t look much different from a run-of-the-mill 3 Series, while the boy-racer look of the original car had its critics, too.
By far the best thing about the E46 M3 is the engine. It’s still an inline six-cylinder, like its predecessor, with a displacement of 3.2 liters. (Technically, it now measures 3246cc.)
Other than its “thrust plate,” the front suspension is nearly identical in design to the E36-chassis car. However, like the rest of the E46-chassis lineup, the springs, shock absorbers, anti-roll bars and other parts are not compatible with the older chassis. Many components that were made of steel on the previous M3 are now cast in aluminum.
The 3mm-thick, aluminum thrust plate is bolted to the bearing points of the two front control arms. Supposedly, by better dispersing cornering loads, this thrust plate helps the car handle better, especially in high-speed, steady-state maneuvers.
At the rear, the design is also similar to the old M3, but more aluminum is used than in the past. Modifications were made to the rear axle subframe, as well as to the final drive bearings.
The E46 M3’s brakes are bigger than on the E36 M3, with vented front discs at 12.8 inches in diameter and rears at 12.9 inches. On non-U.S. models, the rotors are slotted.
These specs add up to an automobile that does practically everything well. Acceleration is electrifying, braking stellar and the whole fit, feel and karma of the car exquisite. The one real complaint is that the ride quality could be judged somewhere between a little stiff and downright tiring.
On the race track, the suspension feels perfect. There is almost no body lean, and the car is completely composed under acceleration, braking and both transient and steady-state cornering. This composure remains intact even at the indecent speeds one might encounter in actual competition.
Despite its awesome potential on the race track, the new M3 does draw some fire for its increased heft. It weighs 3415 pounds, compared to 2800 pounds for the first M3 and 3175 pounds for the second-generation car.
The Experts Weigh In
We asked each of our BMW performance experts to rate the three M cars on the basis of road performance, track performance, ease of modification and reliability.
The results might surprise you, as sometimes newer isn’t always better. In general, the majority opinion was that the E36 was the best of both worlds, as well as being more affordable in relative terms.
James Clay, like most of us here at GRM, thinks that the E30 M3 is the most collectible one of the bunch. “This was my first BMW and still my favorite for a true fun M car,” he says. “There weren’t nearly as many made as the later models, and they were different enough for the normal non-enthusiast to set them apart from the regular 3 Series.
“The S14 four-cylinder engine is full of high-revving fun at the track and very responsive,” he notes, “but the torque isn’t there compared to newer cars and I miss it. Unfortunately, the S14 engine is not very cheap, readily available, or easy to modify. To get 300 horsepower, you have to spend about $10,000, and the engine is starting to push the limits at that point.”
The car’s purer nature also appeals to Clay, as the lack of modern gadgets or overabundant insulation keeps the driver in tune with the road. In his opinion, the cars are also fairly easy to modify, with things just simple enough. The E30 M3 is also the lightest of the bunch.
“I think a well-maintained car is reliable, but too many people forget that older cars require light rebuilds and increased maintenance schedules,” he notes. “This would be the car I would drive as a second car, on weekends and just because I want to drive. The perfect M car.”
The E30 M3 is no stranger to the track, although there is a tradeoff, says Clay. “The E30s are still one of the most fun cars to have on the track, but the technology is just not there to put them at the front of the field and the cost to keep them running is up there,” he explains. “Plus, I hate to take a nice E30 M3 and make a race car out of it—there aren’t as many well-aged ones around anymore and something has to be left to drive one of these amazing cars on the street.”
Will Turner also has nice things to say about the E30-chassis M3, calling it the easiest one to drive on the track, thanks to the car’s light weight and balanced chassis. Turner feels that the E30 is today the least reliable of the three, however. “The E30 M3 is old now, 17 years for many of them,” he notes. “The chassis is good, but the motors are quirky and expensive to fix.”
Bob Tunnell also notes the light weight of the first M3 as a major plus, calling it the best balanced of the three. “It was the best-handling stock-class car I’ve ever autocrossed or driven on the track,” he says. “For the money, a properly maintained E30 M3 is the best performance car bargain in the used-car market.”
The car came from the factory pretty well tuned, says Tunnell, meaning there wasn’t much room for improvement. “The E30 was a race car homologated for the street, so it hit dealer showrooms with little room for improvement available to the average enthusiast,” he points out. “With its one-piece front strut/hub assembly, installing aftermarket shocks was a chore and selection was limited. Sizable horsepower increases were hard to come by unless you went the Evo route, which was costly, to say the least.
“The E30 is probably the toughest M3,” adds Tunnell, “but since they’ve been around the longest, finding one in excellent shape these days can be difficult.”
Jay Mauney pinpoints the E30’s rear suspension as one of its problem areas from a maintenance standpoint. “The suspension geometry in the rear makes dialing in the perfect setup time-consuming and difficult,” he says, “whereas the E36 and E46 are straightforward and adjustments are easy and fast.”
Being oldest doesn’t make the E30 the least expensive car either, as Mauney notes. Those looking for a buildable car should take note that the E30s can cost twice as much as the E36, he explains. Also, spare body and other parts for E30 have now moved into the collector realm, while E36 parts are abundant.
The E30 M3’s bulging flares and tough stance definitely separate it from the crowd, yet the styling still appeals to many of us, including Mauney. “The E30’s raw styling looks still make it my favorite car to look at,” he says. “But a lack of low-end torque requires smooth driving to keep the revs up into the high rpm power range. The E30 even with a full race cage tends to have more chassis flex than the E36 or E46.”
Still, out of the three generations of the M3, Mauney gives the E30 the best marks for steering feel, even though the car can require the most energy from the driver. Maximizing the ability to get the power down in the E30 takes a little more roll-center manipulation than the E36 or E46.
The E36: Perfect Daily Driver
The second version of the M3 was universally praised as having the best combination of good power, weight and handling. It was also felt to be the best street car by some, with James Clay unequivocal: “The E36 M3 is the perfect daily driver. This car marked BMW’s attempt to appeal to the mainstream with their M line, and for better or worse, it is a good car.”
The E36 generation may be heavier than the first version of the M3, but it has tons of torque thanks to the 3.0- and 3.2-liter engines. “They have some isolation for the driveline and enough luxury features to make them extremely comfortable for extended daily use,” says Clay. “I don’t feel bad about putting over 20,000 miles per year on mine, because due to production numbers, it will never be extremely valuable. They are very easy and cheap to modify, and the higher performance European M3 parts drop right in. For a track car, the rear suspension geometry makes them easy to set up correctly and get very dialed in.”
Once the decision is made to go club racing, whether with the BMW CCA or another group, the E36 is hailed as the best car for the job. Once again, Clay doesn’t mince words: “The perfect club racer in my opinion is the E36,” he explains. “They are fast, have the torque of a six cylinder and you can achieve over 300 horsepower with easy bolt-ons.”
The E36-chassis car is also the least expensive one to build, says Clay. “Initial purchase price for a race candidate is low,” he explains. “I paid $800 for my 2003 World Challenge shell and sold the $600 differential for a net expense of $200. Since they share many replacement parts with a standard E36 3 Series, they are cheap to drive and maintain. This is by far the bang for the buck winner.”
Bob Tunnell is also a fan of the E36, the chassis that he has driven to many autocross national titles. “It’s the most fun-to-drive car I’ve ever autocrossed or road raced,” he says. “This car was a joy right out of the box, and to make it track-worthy, it just needed some help slowing down the front suspension with higher spring rates and stiffer shock valving.
“With the modest modifications allowed by SCCA Touring or BMW CCA Stock category rules, this car does everything well,” continues Tunnell. “It will out-corner and out-brake anything else in its class and has enough power to stay with the V8 pony cars on all but the longest straights.”
While the car offered great performance as delivered from the factory, the U.S.-spec E36 M3 came from Germany loaded with potential for tuners to unlock. A wide variety of suspension packages for all budgets is available for even the most modest do-it-yourselfers to install themselves. The S50/B30 and B32 engines are very responsive to software changes, especially the 3.2-liter OBD II engine-management system found in the 1996-and-up models. European-spec and cold-air intake kits are plentiful.
“Several tuners even offer big horsepower gains through supercharging, although reliability and drivability varies greatly depending on brand and quality of installation,” says Tunnell.
Reliability-wise, the E36, with its silky smooth synchros and spongy tranny mounts, is famous for its vulnerability to the “money shift,” so a thorough pre-buy inspection that includes compression and leak-down tests is highly advisable.
For Will Turner, the clear winner is the E36 M3: “It’s the best all-around M3 as far as drivability and reliability goes—easy, comfortable and quick, and the four-door version is kind of stealthy.” It’s also easy to work on and modify: “It’s simply a 3.0- or 3.2-liter version of the 325 engine,” he explains. “BMW built a zillion of them; there are a lot of aftermarket parts available.”
Jay Mauney likes the plethora of aftermarket options for the club racer and the number of expert engine builders that specialize in the six-cylinder engine. “The E36 is the clear choice for a cost-effective racing program,” he explains. “The E46 still has some development ground to cover. Development is expensive and takes time, money and lots of patience, all of which can be outside the realm of justification for club racers.”
The special parts offered by the factory can also benefit today’s club racers, Mauney notes. The optional factory-sourced undertray helps improve aerodynamics and remains legal for BMW CCA Club Racing. “The E36 M3 Lightweight came equipped with an adjustable front splitter and rear wing,” says Mauney, “and although it does increase straight-line drag and slow the car, it vastly improves braking stability and increases overall downforce, which improves handling and grip.”
E46: Mixed Opinions
The latest isn’t always the greatest, with mixed opinions on the E46 M3 from our expert panel. In another step toward appealing to the growing luxury sports sedan market, this M3 was the natural evolution of the 3 Series line. As such, it gained a couple hundred pounds. But in fairness, it also revived some of the once-lost M-specific styling, and the U.S. finally received an engine comparable to the European version.
However, in stock form the E46 is actually a slower car on the race track, which, according to James Clay, is a good indicator of overall handling, acceleration and braking performance. “This car was a further move in the direction of luxury, I think. But, as with the E36 M3, the basic chassis and suspension design are fantastic. Get rid of the weight, and the car comes to life.”
So, if someone wants a luxury BMW that is also fast and fairly nimble, might the E46 M3 be the choice? Well, maybe not. As Clay puts it: “A speed junkie can dust the E46 with half the money in an E36 M3.”
The primary advantage of the E46-chassis M3 over its predecessor is mainly one of aerodynamics. “The E46 engine is close to the E36 Euro engine in output and is already almost maxed out,” states Clay. “To go much further with this car, you have to spend some serious money.
“Its street handling and weight can be easily solved,” he continues, “but the suspension is very similar to the E36, and so many parts still have to be custom-fabricated at this point. The parts offerings will get better as more of the parts are released from the professional race teams, but for now, this one isn’t cheap to drive.” Will Turner says that an E46 M3 with the proper setup has the most track potential, but the lack of feedback to the driver makes it the hardest to race at the limit.
Bob Tunnell gushed about the power of the E46, his enthusiasm obviously apparent. “It’s the most powerful BMW I’ve ever autocrossed or road raced,” he says. “Unfortunately for autocrossers and road racers, BMW chose to strengthen the E46 M3’s road and highway manners over its on-track competency, while its primary rivals on the track—the Corvette Z06, Dodge Viper and Porsche 996—went the opposite direction, seeking out lower lap times as their highest priority.”
Does this mean the newest M3 is a hopeless cause? Tunnell says no. “With a little help, primarily in the form of suspension upgrades, better gearing and reduced overall weight, the E46 M3 won’t surrender without a fight.”
As for modifying the latest M3, Tunnell explains that the aftermarket is currently gearing up to offer the needed hardware. “The E46 M3 is still early in its aftermarket development phase, although several solid suspension packages—like the Bimmer Haus package approved by the SCCA for T1—have been developed that will help the car immensely on the track. Significant engine tuning is just now becoming available through tuners like Eurosport/Conforti and Dinan.”
The most recent M3 developed a bad reputation for early engine problems, although things now seem under control. “Early E46s had numerous problems with the S54 motor, with spun rods often leading to catastrophic engine failures,” Tunnell explains. “But BMW re-engineered the motors in early 2002 and now offers a 100,000-mile warranty. Other ECU-related problems appear to be restricted to cars that see heavy racing use.”
Jay Mauney also commented on the increased weight of this latest generation M3. “The E46 is very heavy, although it does not feel heavy in steering,” he says. “Only under braking does the added weight become real obvious…it requires driver adjustment and more nerve.”
In contrast to some of our other experts, Mauney is itching for the day when the E46 is more affordable and attainable. “Products for the E46 are just starting to hit the market,” he says. “The E46 engine is a dream to work on and build. Just when you thought a car could not be easier to race than the E36, along comes the E46. Aside from the steering feel, the E46 can be raced fast by even a marginal driver.”
As the M3 has evolved during the last 18 years, it seems safe to say that BMW has developed succeeding generations with less focus on the track and more on the road.
Thus, of the three models, the first-generation E30 was judged to be the purest form of the M3, with the most balanced chassis. It was, however, also deemed the least pleasant street car by most of our experts. It was judged too expensive and finicky for contemporary club racing use as well. While the E46 is the most potent street performer, it offers the least civilized track manners.
The E36 was seen as the best compromise between the two, and maybe that’s why it remains the personal favorite of most enthusiasts today. It is competent on the street and, without much modification, at the race track as well.
We would like to thank the experts who evaluated each of the cars: James Clay, Bob Tunnell, Will Turner and Jay Mauney all took time out of their busy schedules to talk with us at the track and in the office.
We also want to thank the folks at the Porsche BMW Owners Club, specifically Bob Turnage, who helped us get these cars on track for our photography sessions during a busy Winterfest weekend. He also helped us hunt down the M cars for our test.
Naturally, we need to thank the owners of these M cars for their cooperation, as well as Yokohama for supplying the tires used for our testing.
You'll need to log in to post.
2 days ago in News
Now is a great time to renew or start subscribing to our magazine.