Ubiquitous, and for good reason. Whether it’s HPDE, a regional race, or the NASA Championships, an E46 is always present. The reasons for this are numerous.
Its robustness, ease of operation, and vast aftermarket probably draw the greatest number of racers eager to try. The sizable footprint and stellar steering help establish an emotional connection, and the fact that it was clearly built for spirited driving only helps. A large engine bay facilitates engine swaps and tinkering, and stellar Bosch ABS gives the amateur something to learn with, and the experienced driver something to rely on. It’s so effective actually, that it gives the tuner an ABS unit to try to integrate into non-E46 cars.
Some fans of the E46 find the term “easy button” less than endearing, but referring to it as “well-developed” not only sounds sweeter, but it’s undeniably true. If a driver likes maximal seat time for minimal effort, the E46 is, without a shadow of a doubt, one of the better paths to follow.
Bad News First
In the interest of objectivity, let’s address its shortcomings before we pay it any more praise.
Any car has a limited shelf life in racing and, as with any car nearing its 25th birthday, many OEM parts aren’t readily available nowadays. “The cost of the S54 and the five-speed ZF have doubled over the last few years,” says Tony Colicchio of TC Design, a Bay Area-based shop specializing in BMW. Driveshafts and axles aren’t as easy to find as they once were.
There are a few other shortcomings. Those interested in running an S54 are well aware of the flawed OEM VANOS valve timing mechanism and rod bearings — two of the “Big Three” issues with the M3. Also, the cooling system is less than stellar, “but with a larger oil cooler added, it’s more than enough for an ST4 and ST3 power. Only at ST2 and above do we recommend aftermarket cooling parts,” Colicchio adds.
Those looking to build a car need to be careful about which donor they pick. Metal fatigue in the rear should be a concern, particularly that around the subframe and the rear spring pocket area — the latter usually caused by the use of cheap, soft, street-oriented springs — should be causes for concern. Pick a tidy donor and avoid costly body repairs.
Some of the thin sheet metal’s issues cannot be avoided entirely. The thin sheet metal around the area where the subframe mounts to the body is bound to crack with track use, and the best way to address this is by tying the rear of the roll cage into a box TC uses to fortify this particular area.
The front of the car is more robust, but it isn’t without issues. Replacing the front control arm bushing, the component designed to take the brunt of the abuse, with a solid or even a poly bushing can crack the inner and outer ball joints. “The front control arm needs to have a stiffer rear mount added to it. At the same time, the control arm ball joints should be inspected and replaced if they have play,” Colicchio advises.
Also, camber plates, which do not distribute the load evenly across the shock tower, can encourage fatigue and tear at the bolt holes. The partial solution is OEM: BMW provides a plate that can be trimmed to fit the top of the shocks. Those looking for a little more resilience can opt for TC Design’s three-eighths-inch steel plate that they weld into their cage tie-ins.
Thankfully, the aftermarket is saturated, and the proven parts packages that, crucially, have been proven to work. Though there are some lousy street-oriented pieces that someone planning a race build should avoid, the knowledgeable members of the E46 scene have done much of the necessary trial and error to establish which parts are truly race-worthy, which parts work well with each other, and where to get them. For this reason, costly experimentation with multiple iterations of a car, as fun as it might be, is not necessary.
An Argument Against Originality
Some might like to blaze a new trail and get the credit for developing an unloved chassis, but the time and money required to diagnose new problems aren’t all that appealing. For instance, the Nissan 350Z might be cheaper to get into, but the available parts are limited and not all have been race tested as thoroughly as a racer would like them to be.
In contrast, the E46 has a wider aftermarket, and the parts are proven. The reasonable running costs can be attributed to the extensive development of the car and the fact that virtually every one of the car’s problems have been addressed. If you want to get in the seat and progress as a driver with minimal wrench throwing, this is a cost-effective way to go.
“We already know which springs, and even which click points on the shocks should be used in a variety of applications. In fact, we’ll be able to shakedown a new car with a proven parts package, and within 20 laps, we’ll be extremely close to the lap record,” says Colicchio.
That a customer won’t have to second-guess themselves and can depend on a reliable car helps them spend more time in the car and less time working on it. This is worth considering, as is the fact that, once past the painful purchase of the car and the major upgrades, the costs dwindle drastically.
“We’re not reinventing the wheel,” Colicchio notes. “The upfront costs are considerable, but that’s only one thing we should consider. Things get cheaper.”
The E46’s chassis is fairly light for its size, and it also has a larger footprint than its predecessor. A good differential design, good strut style suspension with plenty of room for big tires, and great brakes mean it extracts a lot of its performance from its natural agility and surefootedness, whereas some of its heavier rivals rely more on their power to achieve similar lap times. Plenty of power is fine, but at the end of the day, it contributes to greater running costs.
“For example, while an ST3-spec Corvette might cost $500-600 per hour, a comparable M3 might be cheaper by around $100 an hour,” says Colicchio. Over the course of a season, that difference cannot be ignored.
And that sort of cost-savings is considered in many of Colicchio’s builds. “We don’t have to spend eighty to a hundred-thousand right out of the door when someone wants to build an ST3 car. We can work systematically, modifying particular areas in a series of steps rather than doing everything at once. We know the right order of operations here so that the car will continue to work well as it continues to develop.
Milder, Cheaper, Easier, Stronger
Though the years of development have effectively established a spec for ST3 and ST4, they still allow for some freedom of development and exorbitant spending. Those looking to avoid an arms race with minimal wrenching can take the proven Spec E46 route.
Many of the parts needed to run the non-M E46s allowed in this series are available at places like O’Reilly or NAPA. For Peter Jones of Legacy Motorworks, this is a boon for his rental-race service. “I can usually support six cars with one set of spares,” he says.
The motor powering the Spec E46 is not the zingy thing that propels the M3, but it doesn’t cost nearly as much to run. The M54 in the 330i is a torquey 3.0-liter inline six that makes enough power to run quickly. Fun, full-bodied, and responsive, if lacking a little bit of the S54’s motorsport magic, the M54 in Spec E46 trim makes around 220 at the wheels. Power is capped at 225 wheel horsepower, which for a fairly lightweight car, is more than adequate.
The M54 is a workhorse, but it doesn’t like to be overrevved or overheated much. The Spec E46 requires a CSF radiator, but the rest of the factory cooling system is fine for racing. A premature downshift can bend valves and break retainer plates. Avoid those, and it takes the abuse happily. There aren’t any big-ticket items, and although the rod beadings ought to be replaced after 160,000 miles, they don’t cost nearly as much as the S54’s do. “We’ve seen donor cars with 200,000 miles run for several seasons without issue,” Jones adds.
Predictably, the costs are kept as low as possible through the spec as well as the gentleman’s agreement of one set of stickers every weekend. Since the cars weigh only 2,850 pounds with driver, a shoestring operation can make a set last three weekends with a gentle driver who’s content running mid-pack.
A single set of PFC pads and Zimmerman rotors will last an entire season. Front control arms as well as the wheel studs should be renewed at the end of each season. Other than that, it’s a matter of keeping it out of the weeds. Reliable, robust, and happy to take a beating, the Spec E46’s wide appeal isn’t hard to understand.
Meeting Them Halfway
Justin Ross of Magic Developed in Sacramento, Calif., builds many 330is, but not all of them race in Spec E46. He’s found that, although their subframes, control arms, and differentials are somewhat different, the 330i and the M3 share the same tub, and are fundamentally similar enough to explore the potential of the mid-tier E46 and save some cash. Most importantly for the cost-conscious racer, it doesn’t have the pricey S54.
Back in 2017, one client requested they take his Spec E46 and get it ready for the 25 Hours of Thunderhill, where they could still fit into E2 while adding some go-fast bits. After adding a splitter, a wing, and an intake, they won E2 in 2018.
During COVID, things snowballed. The rules for the 25 had changed to suit ST cars, so they tore the car down and rebuilt it for ST5, focusing on trimming weight. Currently, it weighs 2,780 pounds with driver, and with 245 peak horsepower, it laps four seconds faster than a Spec E46 on the same Toyo RR tires.
It runs larger brakes in front — a homebuilt kit using DBA 325 x 32mm rotors and AP Racing monoblock calipers, but the upgrade has paid for itself many times over in consumable costs. “With the white car, we’ve done the 25 Hours, two NASA weekends, and a six-hour enduro on the same Hawk ER-1 pads,” Ross elaborates.
This middle-path has proved fruitful. Magic Developed cars took second overall in the 25 Hour last year. Best of all, it’s significantly cheaper than the M3. It does deserve the moniker “baby M3.”
Pleasures of Conformity
Where the rules sets suit these cars, the ambitious driver looking to move up a class won’t have to change cars. In fact, sometimes the E46 can make a move into a more fulfilling or wallet-friendly class quite easily.
The German Touring Series features five different classes of Porsches and BMWs. The E46 is a major player in GTS2, GTS3, and GTS4. The competitors in these three span quite a large performance spectrum, but the E46 maintains a presence in all. From lightweight E36s and modest 986s to full-bore 911 Cup cars, the E46’s competitors are matched by versions of the versatile BMW in three of the category’s five classes.
“It’s hard to generalize because the cars have to fit into different groups, but the E46’s versatility probably comes down to the following: it’s easy to drive fast, much cheaper to operate than similar Porsches, and more modifiable electronically than any Porsche it competes with. Compared to the E36, it has a better footprint, slightly better suspension, as well as a superior differential,” says Michael Gershanok, German Touring Series National Director.
The officials in GTS have benefited from the car’s electronics with the recent addition of an AiM-supplied data system. This gave them an exhaustive compliance checklist and live comprehensive data to replace a series of somewhat clumsy regulations regarding displacement and so on. “We’ve been successful in policing because we focus on the major parameters and the figures that fall outside of a narrow range. Now with the boxes in place, everybody is kept honest.”
This means that the officials won’t have to work as hard, and neither will drivers looking to jump into a class that is more competitive, cost-effective, or appropriate. As long as they can conform to the power-to-weight ratio and the few point adders in the GTS rulebook, they needn’t make major modifications to put themselves where they’re happiest.
Ease within the GTS rulebook might be a fitting way to describe the entire range of E46 racers: regardless of their budget, there’s something for everyone. Strong, straightforward, sleek, and swift, this versatile little BMW is hard to dislike, and although it’s starting to show signs of age, it’ll likely continue to be a crowd favorite for all the reasons mentioned above.