Das Überwagon: James Clay's Turbo E36-Chassis Wagon


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As the founder and owner of the BMW performance shop and racing dynamo that is BimmerWorld, James Clay knows a thing or two about making BMWs go fast around a track. He got his racing start 10 years ago with the BMW CCA, and has since risen through the ranks to compete in the Speed World Challenge, where he has several top-five finishes to his name.

In addition to his passion for BMWs, it turns out that James is a bit bonkers for station wagons. “I have always loved wagons,” he confesses. “My first car out of school was a 1956 Chevy Sedan Delivery.”

Unfortunately for James, BMW has been pretty stingy when it comes to selling their wagon models in America. Many years ago James laid eyes on an E36-chassis wagon, and he pined for one ever since. He ultimately found one, but not without some international legwork. “I bought this European-only body style BMW Touring from a friend in Sweden who located it for me after two years of digging,” he says of his 1995 wagon.

James was only interested in an extremely clean car with no rust, a tall order when shopping for BMWs that are typically used by families banging around the Alps. When the friend finally located the right car, he disassembled it and placed all of the parts in a shipping container. He sent it off to James at his BimmerWorld shop in the U.S.

Once the car was in the shop, the wagon fanatic in James started conspiring with the performance nut residing elsewhere in his brain. This humble 2-liter BMW Touring wasn’t going to be humble for long.

A Few Minor Power Upgrades

“The car was initially going to be my lightly hotrodded daily driver,” recalls James, “but it doesn’t take much for me to get fired up about a project and go overboard.”

Rather than preserve the BMW as a low-key daily driver, he and the BimmerWorld team decided to make it a unique showcase for their company. It would still be street legal, but it would primarily serve as a fun track toy. “This is a very technical car,” explains James. “We worked with all of our World Challenge sponsors to take the same technology we race and put it in a streetable track car.”

Any chance this 320i Touring had of living a tame life ended when James started tinkering under the hood. Out came the 1991cc inline-six, and in went a low-compression 3.2-liter six from an E36-chassis BMW M3 that had been built by Sunbelt Performance Engines. As if that weren’t enough, the team fabricated a true 6-into-1 top-mount tubular manifold that plugged into a Garrett GT40R turbocharger.

“[We put in] quite a bit of effort to make the pulses hit properly for faster spooling at the track,” James says of the turbo setup. “Lag is reduced with a 0.85 turbo A/R ratio. We can get about 470 wheel horsepower from the car with the base boost level of 10 psi, and up to 650 wheel on pump gas [with the boost] turned up—that’s about 800 at the crank on pump gas.”

Fast Ain’t Easy

Going with such a potent engine wasn’t without its headaches. The biggest issue James encountered was, not surprisingly, heat under the hood. The initial temperature control plans called for a 57mm-thick PWR Performance Products radiator and a big, two-pass, Fluidyne tank-style oil cooler, but that turned out to be just a starting point.

“In the first track test we melted lots of stuff,” recalls James, “plus the engine was running at 220 [degrees Fahrenheit] and climbing.” They swapped to a single-pass, Setrab plate-style oil cooler that was larger than the Fluidyne unit, and then went to work physically corralling the heat.

“We were fanatical about coatings and wraps,” James explains. “The downpipe and intercooler pipes use a Jet-Hot Extreme Sterling coating, while the manifold and turbo exhaust housing use a higher-temp Jet-Hot 2000 coating.” The latter is designed to protect substrates at temperatures up to 2450 degrees Fahrenheit.

“We then wrapped the full exhaust, installed a turbo blanket sourced from Australia that has a ton of insulation, and used a lot of reflective films and insulating hose wraps,” James continues. “Now the temps are solid at 195 and you can touch everything under the hood right after coming off track.”

Another less dire snag was finding room for the air filter. With so much space being gobbled up by the top-mount turbo and the Euro-spec self-leveling headlights, there wasn’t much room for a filter. James almost gave up on his hopes for a stock exterior and considered putting a bubble in the hood, but a few hours of tinkering led to an air intake design that fit.

Following Suit

With a new heart generating as much as five times the stock engine’s output, the rest of the modifications could almost be viewed as simple safety necessities to keep the thing from being a one-way express to the tire wall. The brakes, suspension, safety gear and more would have to be dramatically improved. Good thing BimmerWorld is a pro race shop.

A quick glance at the spec box will confirm that James and the BimmerWorld team left no essential component unimproved, and they didn’t skimp on the important bits. For brakes, James chose the same Performance Friction zr28 zero-flex monobloc calipers that are used in Champ Car and on the BimmerWorld World Challenge racers. Traction was similarly upgraded thanks to 18x9-inch D-Force wheels wrapped in 245mm-wide, C50-compound Hankook Z214 DOT racing tires.

The list is long, with Moton dampers, Ground Control springs and Arrow connecting rods; true to its owner’s word, the BimmerWorld Überwagon is a rolling showcase for the team’s sponsors. There’s nothing frivolous, either, as every upgrade addressed a particular need. Some of these needs only became obvious as the project neared completion.

“The rear spoiler was a last-minute addition,” James recalls. “In initial testing [at VIR], the car was doing 140-plus at the small kink in the start/finish with only 10 psi and no front splitter. The rear end slipped sideways repeatedly.”

James didn’t want any aero work to detract from the car’s basic shape, but he also didn’t want to loop the car at more than 160 mph when running under full boost. The result was a low-profile removable aluminum spoiler fabricated the night before the UTCC.

Hauling More Than Groceries

The Überwagon made its competition debut at GRM’s 2007 Hankook Ultimate Track Car Challenge, but a top-10 overall finish was not to be. A finicky wastegate was causing overboost issues, and the head gasket simply couldn’t handle the extreme pressure. The gasket was going soft, and after the second timed session James decided to pack it in for the day rather than cause a more serious problem by pushing the issue.

Still, this monster BMW wagon managed an 11th-place finish with an impressive 1:39.734 lap on the VIR North Course. In the months since the UTC Challenge, James has swapped the head gasket, upgraded the boost reference lines to braided stainless and added even more insulation. He’s also switched to a carbon fiber hood.

“I was at VIR last weekend—the Full course—and decided to take it out on street tires and pads,” James recently told us. “I almost hit 170 on the back straight—and successfully slowed for Turn 14. It is a pretty wild ride.”


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Comments
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CyberEric
CyberEric Reader
3/9/18 11:31 a.m.

Man, I've had lust for that car for years! So cool!

vbM3
vbM3 New Reader
3/9/18 1:19 p.m.

Wagons are the best!!!

funfunfer
funfunfer New Reader
3/9/18 4:39 p.m.

Thanks to James and crew for reviving memories of the "Car & Driver" series of Boss Wagons from , and I'm guessing at this, the '60s-'70s.   

MazdaFace
MazdaFace HalfDork
3/9/18 6:58 p.m.

i love it

TreDeuce
TreDeuce New Reader
3/10/18 12:24 a.m.

As a long roof fan, I built a 2002 525I Touring and replaced the drive train with an m5 engine and gear, keeping only the steering rack of the 525i.  It is not a race car, but it is a quite satisfying touring car and I should have kept it.

Randy_Forbes
Randy_Forbes New Reader
3/10/18 7:40 a.m.

Wow James, nice car.  Has all the good stuff on it too!

By the end of the second paragraph, I'm thinking BMW Sedan Delivery...

Start with a 2-dr coupe body, and graft the back half of the wagon (roof & tailgate) onto it.  Solid panels aft of the doors (no side glass behind the longer coupe doors).  Maybe re-profile the  trailing edge of the door glass to match the angle at the tailgate.

Should probably work out the details on a 1:18 scale model first!

Maybe a 5 Series would have better proportions for a starting point...

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