Meet the Bergsteiger, BimmerWorld's 1000-plus horsepower E36-chassis BMW M3 Pikes Peak racer

David S.
By David S. Wallens
Apr 19, 2022 | BMW, e36, M3, Bergsteiger | Posted in Features | From the Oct. 2020 issue | Never miss an article

Photography Credit: Kevin Adolf

The project started with a seemingly simple question: What’s awesome?

The “what” referred to the motorsports events that make up our scene. The question was posed by OPTIMA, the battery company popular in the enthusiast market. James Clay, owner of BMW tuning house BimmerWorld, was the one being asked. The question basically represented a blank slate for his next giant motorsports project.

Pikes wasn’t anything I really thought I’d do,” he now recalls. But he couldn’t deny it: Racing up Pikes Peak sounded awesome.

Photography Credit: Kevin Adolf

Killing It: The Need to Do More Than Just Participate

That original conversation took place early in 2017, and that summer James made his Pikes Peak International Hill Climb debut in a relatively mild E92-chassis BMW M3. The project more or less represented the standard track build: a little more power for the naturally aspirated V8, a bit less weight courtesy of some carbon-fiber parts, and then some proven aero add-ons. The car could have been built right out of the catalog, since just about everything was a bolt-on part.

“It was a solid rookie car,” James recalls. It was reliable and fast enough to put him in the top third of the field.

James Clay, shown with a feathered friend made during dyno testing, had a vision: an E36 shell stretched to the max. Photography Credit: Kevin Adolf

“But I find it hard to do events like that and do it once,” he continues, explaining how people can dedicate years to winning or even dominating an event. “It’s like the 24 hours at the ’Ring. That was fun. Now I want to kill it.”

The dream of killing Pikes Peak meant that James needed a faster horse. “Number one, we need a turbo,” he explains while looking back. The Pikes Peak course starts at 9390 feet above sea level, with the checkered flag coming at 14,110 feet. “The only way you’re going to do well at that mountain is with a turbo.” And then it would need some serious aero.

Escalation: Engage

The shopping list for the specialized Pikes Peak build was fairly brief: turbo power, lots of aero, and a BMW Roundel on the nose. And, of course, it had to be awesome.

BMW has built a lot of choice cars over the years, but James quickly gravitated toward an old favorite. “The E36 is just an iconic car for me,” he’s quick to explain, as his company has been working with them for decades. “I think it resonates with so many people.”

An E36-chassis 3 Series would be practical, too: “And it’s super lightweight.”

The car has long been raced on both the professional and amateur circuits. In the ’90s, the factory-backed IMSA team was highly successful with this model—and James knew that its bodywork was key, as it made actual downforce. His creation would be called Bergsteiger, German for Mountain Climber.

The original plan, he recalls, was somewhat simple. Take an E36 coupe, add the IMSA bodywork, and give it about 900 horsepower. The team originally planned for a “monster” build involving BMW’s N54 engine, the turbocharged inline-six found in many 2006-’16 models, including the 135i, 335i and 535i.

Then, one day, BimmerWorld ran a then-new BMW M6 across the dyno. With just an Epic Motorsports flash tune, its twin-turbo V8 easily made 800 horsepower, all while remaining docile on the street.

“I’ve seen and avoided escalation,” James admits, “but I also thought it would be super cool, and I kinda let that win out. Suddenly, our inline-six grew to a V8.”

Go Big: a Big Plan for a Big Mountain

The escalation, James admits, came quickly. The V8 doesn’t easily fit in the space once occupied by an inline-six, and that’s before adding the associated coolers and radiators. It’s simply a wider engine designed for a bigger car. As a result, the original front frame rails had to go.

But why bother with the pedestrian V8 when they could run the Motorsport version found in the M6 GT3 pro race cars, an engine that could be built to produce more than a thousand horsepower? Bonus: The team could then run a rear-mounted transaxle, allowing the engine to sit low and back in the chassis.

They cranked the knobs further: The original plan called for a pair of tunnels to serve as the foundation of the car’s downforce, but what if those tunnels were even bigger? “And then it went into creep mode,” explains Rich Grupp of Fabworks Machine and Design, the shop that built the car in conjunction with Wayne Yawn, BimmerWorld’s race engineer. “You do one thing, but it affects five other things.”

The amount of work this required meant that this machine wasn’t going to make the event in 2018–and maybe not even 2019. “So we said,” James recalls, “‘we’re going to miss it anyway, so why not do this?’”

After cutting off the stock frame horns, a tube chassis was constructed to support the engine and front suspension. This structure is tied to the roll cage and features a much lower ride height than stock.

The stock rear end was shed, too, replaced with E46-chassis BMW trailing arms attached to a custom, CAD-designed cradle for the transaxle, fuel cell and all-important OPTIMA battery. The rear fenders, along with the IMSA kit, had to be cut, sectioned and massaged to fit.

The original plan called for twin tunnels running along either side of the driveshaft to add downforce, with the molds coming from an ’80s-era Argo GTP Lights car–a machine built when loose downforce rules allowed much creativity. “Tunnels are core to the build,” James notes.

The team first figured that they could create enough clearance by raising the stock floor. But after they realized lengthening the tunnels by 2 feet would yield even more downforce, the stock floor was eventually tossed. “It was easier to cut it out and tin over it,” James admits. The tunnels, visible from the back of the car, now start beneath the driver’s legs.

The splitter design came from the Lola B2K/40 prototype machine, another successful race car of the past, while the wing is an AJ Hartman piece. “If you can steal it, it’s way better than inventing it,” Rich adds.

Other aero enhancements include vortex generators on the end of the splitter that keep the passing air from being sucked into the tunnels, along with a vented hood for more downforce via air extraction. At speed, the entire aero package yields 3500 pounds of downforce, all on a car that, with driver, weighs 2800 pounds.

The biggest trick, Rich says, was making everything fit. Even with the huge fender flares, the Bergsteiger is about 4 inches narrower than BMW’s current GT Le Mans car.

The radiators and coolers were a big struggle, Rich explains: “We have a lot of horsepower, and you have to get a lot of surface area in there.” The team also had to factor in the altitude and install the required structural supports. “That was keeping me up at night.”

Photography Credits: Courtesy BimmerWorld

Chip Challenge: Brains for the Bergsteiger

Now to bring it to life. Eric Scheib of Electron Speed wired the entire car around a Bosch Motorsport MS 6.4 control unit. This ECU family can be found across the top end of the motorsports spectrum, from MX-5 Cup to the factory-supported GTLM efforts.

The biggest challenge for any modern ECU, explains longtime race engine tuner Ed Senf, is working with direct injection. “Injector characterization and high-pressure pump control are very difficult,” he says. “My role primarily revolved around integration of switched inputs and driver controls: gear paddles, map and boost switches, etc. I also helped sort out communications from the ECU to the dash display logger and ABS system.

“Lots of CAN bus messages to write and sort,” he continues. “Dyno tuning as usual plus paddle shift calibration was also part of my task list.”

The powerplant is tuned to make about 1150 horses at the wheels at sea level. That should translate to roughly 800 horsepower at the Pikes Peak starting line.

“Air keeps getting thinner and thinner as you climb,” Ed notes. “I don’t have personal experience at Pikes Peak, but working with other turbo cars at various altitudes in racing has taught me that boost control calibration takes more forethought than one might expect.

Building Anticipation

Despite all of the custom hardware, this machine still resembles the donor car. “The shell’s there, but a lot of modern fancy bits now live under it,” James says. “The E36 DNA is obvious, though.”

One of the project’s goals, he adds, was to keep strong ties to BMW. The hood, door and trunk hinges, for example, are still BMW parts. The angles and contours recall the original car. It’s not the traditional tube-frame, silhouette funny car, where Dzus fasteners secure panels that barely approximate the street car.

James says to think of it as a vintage take on the modern GT Le Mans cars. “We’ve incorporated a lot of BMW parts and technology,” he adds.

Another goal, he says, was to work with lots of good people: “And that’s the fun part of any project.” Early testing took place at the BMW Performance Center, a facility whose staff was eager to see the car.

Photography Credits: Kevin Adolf

The Bergsteiger made its SEMA Show debut last year and appeared in several YouTube videos this summer. Pikes Peak might have to wait until 2021, however, as the current pandemic bumped the hillclimb back from its traditional July date to late August-right on top of an SRO race weekend, meaning a conflict for the BimmerWorld team.

But look for the car out there in the meantime-likely in time trial competition. “Once we crank up the boost, top speed at VIR is over 200,” James says before adding one last item to the spec sheet: “It’s absolutely going to have a passenger seat.”

Photography Credit: Kevin Adolf

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Comments
pinchvalve (Forum Supporter)
pinchvalve (Forum Supporter) GRM+ Memberand MegaDork
8/20/20 3:07 p.m.

Looks like 1/2" plate steel. I'm sure it's not, but that would put some weight on the rear tires!

Kevin_at_BW
Kevin_at_BW GRM+ Memberand New Reader
8/20/20 3:40 p.m.

In reply to pinchvalve (Forum Supporter) :

Speaking of the tunnels?  All carbon fiber baby!

759NRNG (Forum Partidario)
759NRNG (Forum Partidario) UltraDork
8/20/20 6:18 p.m.

This is by far a beast for sure......and correct me if i'm wrong....but haven't all the fastest up the "hill" been AWD?

Kevin_at_BW
Kevin_at_BW GRM+ Memberand New Reader
8/21/20 12:38 p.m.

Not since it was completely paved, no. They don't take absolute top billing, but RWD definitely has plenty of grip and go fast ability to the top now.

wspohn
wspohn Dork
8/22/20 1:39 p.m.

I think you might need a steeper angle on that front air foil if you want the critters you hit to clear the roof on the way up......

jerel77494
jerel77494 New Reader
12/9/21 2:28 p.m.

Looks like rear shock travel is real short!

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