Bavarian Bruiser - Track-Ready Diesel-Swapped BMW E91 335d

Eighteenth-Century English Poet William Blake once wrote that the road of excess leads to the palace of wisdom. If this is truly the case, enthusiasts like Brian Marks must surely be wise beyond their years. He has a history of taking things to the extreme in his quest for the ultimate BMW, and this beautiful E91 Touring here before you is the latest of his creations. If you think there's nothing excessive about this seemingly innocent family station wagon, how do 400 horsepower, 600 lb-ft of torque, and 40 miles-per-gallon grab you? And that's just the start. 

Brian is a bit of a BMW fanatic, having owned many variations for the street, work, and track cars over the years. It all started with an Orient Blue 330Cic back in 2002, purchased brand-new for his wife after finding the BMW a more rewarding drive than the Mercedes that she had originally fallen in love with. Fast forward a few years, and Brian's pristine Avus Blue E36 M3 was totaled in a serious crash courtesy of a distracted driver. The injuries sustained in the crash caused Brian to swear off coupes in favor of sedans, with their safer and more robust B-pillar. 

The resulting settlement from the crash allowed Brian to purchase his dream car, an exceptionally clean and lightly-used E39 M5. From there, the possibility of starting a family led to the search for an E39 Touring, which was acquired and then underwent a variety of upgrades, swaps, and engine configurations. It was eventually converted to full M5 spec, only to be sold almost immediately after it was completed on Bring a Trailer. 

A spin behind the wheel of a friend's BMW 335d Touring, and having spent some time behind the wheel of his wife's X5 xDrive35d daily driver gave Brian an appreciation for the torquey diesel engine. It was all he needed to jump back into the wagon-world. 

"After driving a converted 335d Touring, I was stunned at how amazing the performance was of the same engine in the X5, but in a vehicle weighing 1500lb less." Brian begins. "If he could build one, so could I, but my wife, who hasn't driven an automatic ever until we got her the X5d, said that we absolutely had to have at least one fun manual car in the household. And why do a sedan when you can do a unicorn wagon?"

I'm certainly not going to argue with that logic. So with that in mind, Brian located a two-owner BMW E91 wagon on the West Coast, with only 82,000 miles and finished in rare Montego Blue. He then began the painstakingly complex process of converting the automatic, gasoline-powered, all-wheel-drive car into the manual, turbo-diesel, rear-wheel-drive beast you see here. The process was essentially a ground-up transformation, leaving no part of the original car untouched. As you might expect, the car's electronics proved to be one of the most challenging parts of the process. 

"All the wiring had to be redone, and also several features of the body harness of the donor car had to be extricated and integrated into the wagon," Brian explains. "The auxiliary cabin heater, fuel filter heater, electric engine fan, ABS/DSC, and more are vastly different. Then all the coding of different modules and so on; it was a challenge for my coder at BPMSport."

You'd be forgiven for thinking that the 335d's 3.0 L turbo diesel making 282 horsepower and 428 lb-ft of torque would be enough, and it might be for some people. Brian is thankfully not one of those people, and so in honoring the idea that 'more' is better than 'some,' Brian started to turn things up. 

He installed the engine fitted with a pair of Tune My Euro v2 hybrid turbochargers, along with a larger BMW R90 fuel pump, ATM SpeedShop intake and exhaust systems, and a front-mounted intercooler. A stock manual transmission from a European 330d was sourced and installed, with a Clutchmasters custom single mass clutch and flywheel system, along with a BMW 2.35 rear end. At the same time, a Wavetrac differential does it's best to meter the power out to the two rear wheels. A JR Stage 4.1 DDE tune has the twin-turbo straight-six making somewhere in the range of 400 horsepower and 600 lb-ft of torque. 

With that much torque on tap, it would have been insanity to leave the brakes as delivered from BMW. Massive Stoptech brakes are at all four corners, with ST60 6-piston calipers and 355mm brake discs up front, and ST40 4-piston calipers with 345mm brake discs in the rear. Brian selected Gloss gunmetal Bimmerworld TA5R wheels, measuring 18x9.5 front and 18x10 rear, and had them wrapped with Michelin Pilot Sport 4S tires, measuring 265/35 R18 and 275/35 18 respectively. 

When asked if the temptation or ability to turn that expensive Michelin rubber into smoke was something he could resist, Brian said that the wagon hooks up without too much trouble despite the massive torque. 

"The Michelin tires grip really well, and with the really small rear gear and the fact that the turbos don't spool up immediately, I can launch it pretty hard and not smoke the tires much," he enthused. "It's a really interesting dynamic that you'd have to drive to understand."

With years of on-track experience behind the wheel of various Corvettes, M5s, and M3s, the suspension is an area where Brian wasn't about to do things by halves. The upgrades center around a set of double-adjustable custom MCS 2-way coilovers, featuring 550lb front and 850lb rear spring rates and remote reservoirs.

The control arms are upgraded for better performance and geometry all around, with a complete set from Bimmerworld on the rear and M3 control arms and ball joints up front. Bushings are all solid except for the 95A durometer polyurethane subframe and differential bushings. He also installed an Octa Motorsports rear differential brace to help with launching and high-torque stability.

Of course, with so much attention paid to the mechanical systems, it would have been insane not to improve the aesthetics as well. Brian turned his attention to the body, aggressively massaging and rolling the fenders at all four corners to better fit those big Michelins and aggressive ride height. 

Several additional changes took place, including a full M-sport conversion with functional front and rear BMW Park Distance Control and headlight washers. Various bits, including the badges and roof rails, were deleted before the entire shell was resprayed in a fresh coat of Montego Blue paint. Gloss Shadowline trim and paint protection film complete the look on the outside. 

Brian's day job is actually in the leather and vinyl repair world, as the owner of Fibrenew North Raleigh Wake Forest. If that name seems familiar, it could be because his handiwork was featured on the AMMO NYC YouTube channel. Thanks to prodigious experience with repairing and restoring all manner of vinyl, leather, and other various materials, tackling the interior of his E91 Wagon was nothing short of thorough and exacting. 

Custom two-tone black and orange leather seats with matching door panels take center stage and an M3 steering wheel, M-sport upper pillars, headliner, European armrest, and carbon fiber trim complete the primary interior treatment. The instrument cluster features a custom 335d logo, while illuminated 335d door sills, 335is manual pedals, and a ZHP 6-speed shift knob round out the final touches. The end result is one that Brian is understandably happy with.

"The final package is incredible. The handling is like a track car, but it's also comfortable and quiet. It is mean sounding under heavy throttle, it pulls like a freight train, and it's a beautiful color inside and out," Brian enthuses. "The feeling of sitting behind the wheel, rowing through the gears is sublime. It's definitely a head-turner but also backs up its appearance with ridiculous performance. "

"The final piece in all this is actually FCP Euro," he adds. "With the Lifetime Replacement Guarantee, I can actually afford to keep my cars maintained and serviced with all OE BMW parts if I so choose without breaking the bank. And of course, my employee and friend, Nick, happens to have previously been a BMW master technician, so he helps a ton as well." 

Brian credits Nick with much of this build's success, having handled all of the complicated wiring changes, additions, and rewiring the DDE, body harness, and ABS/DSC systems by hand. An impressive feat, given the daunting task of going through these systems harness by harness and wire by wire and ending up with flawless functionality.

When asked if he plans on selling this one on, the same as he did his original M5 Touring, the answer is a (mostly) firm "no."

"My current plan is to keep it and drive it as often as I can. I chose to do it perfectly and "over the top" from the first moment rather than to perfect it just before sale so that I could enjoy it myself this time," he explains. "People have asked if I'm selling and what my price is, and I simply told them that there have to be at least six digits in the offer for me to even consider selling it so soon after completion."

Still, from what we hear, there's another BMW Touring model that Brian's been working on for some time, and thanks to the unexpectedly high price his old M5 sold for, that project may end up being completed as well. Needless to say, I think we'll need to stay in touch and see what develops. We could all use a little more wisdom in our lives. 

 

Thanks to:

I want to thank Nick Trapp, my buddy, and an amazing technician for making it happen, along with Paul Martin, Jeff Cash, and Stephen Gilbert, for helping with all the mechanical disassembly of both cars. Then there's James and Phil at Bimmerworld for extremely good service and support and killer goodies, Dennis at Schmiedmann in Denmark for helping source all of the Euro goodies for the E91 and a bunch more for the E46, Mike at BPM Sport for his expert coding and technical skills making everything work so nicely together, and Neal at Precision Collision for the amazing better-than-factory paintwork. Without this team, no matter how much money or time you would have thrown at such a project, it wouldn't have happened this way and in such short order.

Photos

•  Dan Pajerski

Specs

Engine

• 3.0 L BMW M57D30TÜ2 diesel engine
• Tune My Euro v2 Hybrid Turbochargers
• BMW R90 fuel pump
• ATM SpeedShop Front-mounted intercooler
• ATM SpeedShop Cold Air Intake
• ATM SpeedShop non-muffled exhaust
• JR Stage 4.1 ECU Tune
• 400hp / 600lb-ft, 40 mpg (estimated)
• Functional fuel filter heater wired in from diesel donor car

 

Transmission

• Donor 330d 6-speed transmission from Denmark
• Custom Clutchmasters single mass flywheel and high torque clutch
• BMW 2.35 rear ring / pinion
• Wavetrac Differential by Diffsonline
• Brand new BMW driveshaft and guibos from Schmiedmann in Denmark

 

Brakes

• Front - 355mm StopTech w/ ST60 6-piston calipers
• Rear - 345mm StopTech w/ ST40 4-piston calipers 

 

Suspension

• MCS 2-way Coilover suspension w/ remote reservoirs 
• 550lb springs front
• 850lb springs rear
• Hotchkis swaybars, 
• Solid bushings or bearings throughout 
• 95A polyurethane subframe bushing 
• 95A polyurethane differential bushings
• Bimmerworld adjustable rear control arm kit
• Octa Motorsports Diff Brace
• M3 front control arms 
• M3 front ball joints

 

Wheels and tires

• Gloss gunmetal Bimmerworld TA5R 18x9.5 front
• Gloss gunmetal Bimmerworld TA5R 18x10 rear
• Michelin Pilot Sport 4S 265/35/R18 front tires
• Michelin Pilot Sport 4S 275/35/R18 rear tires

 

Interior

• Completely customized by Fibrenew Raleigh
• Two-tone custom black/orange leather seats
• Matched custom black/orange door panels
• Custom coding by BPM Sport to make everything functional including BMW apps, navigation, Logic 7 audio, and all original wagon features
• Custom 335d logo cluster with white illumination LEDs by Bill Gee
• Carbon fiber trim by Stitched Wheels
• European center armrest
• M3 steering wheel
• ZHP 6-speed shift knob
• 335is manual pedals
• Illuminated 335d door sills by OEM Customz, connected to door lighting with fade on/off
• M-sport upper pillars and headliner conversion
• NC-Legal window tint 
• Fully functional auxiliary dash heater wired in from diesel donor car

 

Exterior

• Factory Montego Blue, fully repainted
• Rolled fender arches at all four corners
• M-sport front and rear bumper conversion
• Functional BMW PDC and headlight washers
• Debadged 
• 4" custom exhaust tips
• Roof rails deleted
• Pre-LCI side mirrors with functional electric folding
• European tail lights with functional rear fog lights and interior switch
• Full paint protection film on front end, A-pillars, rockers, and rear bumper by All Pro Window Films in Raleigh NC
• Gloss Shadowline trim
• Factory correct underhood decals for diesel emissions, refrigerant, belt routing, etc

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Written by :

Nathan Brown

FCP Euro's Event Director by day, writer and contributor by night, and wanna-be race car driver on the weekends. Nathan has been working in the VW and Audi performance aftermarket for nearly two decades, and dabbled with Porsche and BMW. He also used to write under the pen-name of Alex Rogan for magazines like Eurotuner, Performance VW, Total 911, and European Car. He has a Cornflower Blue Rabbit Edition GTI daily driver which is surprisingly still mostly stock, and a Mk5 GTI track car which is mostly not. ••• Instagram: @njbrown55