JUS’ BUGGIN’: Grégoire Blachon’s Diesel Pike’s Peak Racer

There’s much more than meets the eye with this 2007 Fun Cup Racer. It’s been styled after a typical early-model VW Bug with a rear-mounted 2.0L Common Rail diesel engine propelling it to Pike’s Peak glory. Grégoire Blachon is a mechanical engineer and the owner of Boxeer Diesel Motorsports in Nashville, TN—He’s also an avid gearhead and automotive enthusiast that enjoys racing, camping and of course diesel performance.

One of his desires has been to build a diesel-powered rig to compete in the “Race to the Clouds” the world-renowned Pike’s Peak International Hill Climb held annually in Colorado with a modest budget that other hobbyists could relate to. With that in mind, he began the hunt for a VW Beetle-based Fun Cup race car. The Fun Cup cars are part of a spec racing series in Europe that at one time had plans to expand to the US. Importing a Fun Cup car from Europe was cost-prohibitive but he didn’t give up on the idea and kept searching for something similar here in the States.

Looking at the low-slung Boxeer Fun Cup racer with big openings and heat exchangers up front might lead you to think it’s a front engine Bug. But, on closer examination you will see the fuel filler in the top of the hood showing that something else resides under the one-piece front clip.

During one of his many searches for a Fun Cup racer, he came across the ad for a Fun Cup car that was the actual car that was sent over to the US in 2007 in hopes of selling the cars and establishing the race series here in this country. The 2007 effort was not deemed a success and the car went into storage and eventually into the hands of an owner in Colorado that decided to let it go in 2016.

Upon finding the car and contacting the owner Grégoire hopped in his truck armed with an empty trailer and drove straight through to Colorado from Nashville, TN that very night to purchase the car. He also found out from the owner that a set of body molds were also imported with the car in 2007. He hunted them down and purchased them as well and now has the capability to manufacture body panels in fiberglass or carbon fiber for Fun Cup cars here in the US.

With an easily removable one-piece front end and tilting one-piece rear bodywork the Fun Cup bug is easy to work on and service with everything easily accessible. With the front hood removed you can see the Fuel Safe fuel cell, as well as the fabricated chassis complete with Eibach coil-over strut mounts for each corner. Looking closer you can see the Mishimoto radiator and Frozen Boost heat exchanger for the air-to-water intercooler as well as the brake cooling ducts and small HID headlights.

Located behind the Fuel Safe fuel cell are the fluid reservoirs for the clutch and brake systems as well as the VW external fuel pump. You can also see the steering shafts for the center-driven car.

After getting the white and green Fun Cup car back to Nashville Grégoire went to work crafting his diesel-powered road racer. The common rail VW TDI diesel engine he installed in the car is one that he offers through Boxeer as a stand-alone diesel engine package. It’s been used in a wide variety of applications including a boat, plane, generator, lightweight drilling rig, and even some military applications.

Boxeer also has an engine lab with dyno and combustion analysis capabilities to fine-tune customer engines to their precise needs. The particular engine in the Bug was previously used in a drilling rig before it was repurposed for racing action.

The lightweight Boxeer Diesel Motorsports Fun Cup car looks pretty much like a run of the mill VW Bug but this slick little racer has challenged the Pike’s Peak International Hill Climb, one of the most demanding races in the world! Looking at the car in profile reveals its racing intentions with massive rear wing, dual inlet NACA-duct in the rear windows, staggered tire fitment and roof scoop. Easy access: with the front hood removed and the rear hood tilted back out of the way you can see how easy it is to service the car between races.

The Fun Cup car had a VW 4-cylinder gasser engine and transaxle installed in the rear when he bought the car. It was immediately yanked from the chassis to make room for the turbo-diesel power plant and matching manual transmission. The first VW diesel Grégoire put into the bug was based on the CJAA VW engine that made around 250-horsepower with the Boxeer modifications.

He later swapped that one out for a CUAA TDI engine that made 350 horsepower and 550 lb-ft of torque after he tuned and modified it. The fuel injection system is running at 2000 BAR of fuel pressure with Bosch injectors capable of delivering 450 horsepower worth of fuel to the small 4-cylinder diesel.

He used his Boxeer stand-alone ECU and built custom harnessing to tune, operate, and control the TDI engine. Internally the engine is also enhanced with a Colt Cams camshaft to wring some additional power out of the 2.0L engine while offering precise control of valve actuation.

Rather than stick with the small factory VW turbo and its integrated exhaust manifold Grégoire upgraded to a larger Garrett GTB2260VK turbo with a Darkside Developments tubular manifold to maximize the exhaust flow into the turbo. The roof scoop forces air into both the K&N air filter to feed the engine and the silicone ductwork to flow cooling air through the engine oil cooler. You can also see the air-to-water intercooler next to the oil cooler at the rear of the engine.

Spent exhaust gasses are channeled through the tubes of a Darkside Developments tubular header with a Garrett GTB2260VK turbo. A short length of exhaust tubing runs from the turbine outlet to the outside of the car on the passenger side of the rear bodywork. Clean air is force-fed into the turbo from a duct connected to the roof scoop that flows down through a K&N air filter then directly into the compressor inlet of the Garrett turbo.

The compressed intake charge is then fed through the factory VW air-to-water intercooler then into the engine through the integrated intake manifold. The water is pumped up to the front of the car where a Frozen Boost heat exchanger is joined by a Mishimoto radiator to keep the intake charge and engine cool.

Looking below the rear of the car you can see the Fun Cup square tube chassis along with the lower control arms and CV axle shafts. The Fun Cup “Bug” is race ready; notice the “D” symbol on the rear fender indicating to course workers that this is indeed a diesel powered race car.

The TDI engine is backed by a VW 5-speed manual transaxle with gear ratios matched for the diesel powerband. A Sachs Stage 2 clutch, pressure plate, and flexplate are used to link the diesel engine to the transaxle and handle the high power and torque output without failing. To put the power to the ground consistently while allowing the car to handle the tight twists and turns of Pike’s Peak Grégoire replaced the VW open differential with a Quaife limited-slip differential.

He also installed custom CV axle shafts from the Driveshaft Shop in North Carolina to get the power from the transaxle to the wheels. A future upgrade that he hopes to integrate into the car is the installation of a 7-speed DSG transaxle with a Wavetrac limited-slip differential for quicker shifts and to keep the diesel in its powerband even better.

VW disc brakes clamp on all four corners with aggressive pads to slow and stop the car with authority without breaking the bank. Since the car weighed about 2,000 pounds in its first Pike’s Peak attempt, Grégoire has put it on a strict diet since then getting the weight down to 1,635 pounds. He is able to get away with production style braking rather than the exotic and expensive components that super-funded teams rely on.

Up front the Bug rides on a set of 8-spoke 15x7-inch wheels wrapped around BFGoodrich g-Force Rival 205/50ZR15 tires to carve the corners without adding a bunch of unsprung weight. VW Golf disc brakes with aggressive race pads slow the car for the tight turns of the Pike’s Peak Rally. The rear of the Fun Cup rides on a set of Braid 10-spoke Fullrace A 16X11 wheels wrapped in Toyo Proxes R888 255/50ZR16 tires for maximum grip as the common rail VW TDI engine puts the power to the ground. Also notice the NACA-duct integrated into the rear fender for brake cooling as well as the roof scoop that is used to draw cool fresh air into the turbo and provide airflow over the engine oil cooler.

Moving inside the Fun Cup car you can see that it was designed specifically to race with a center-mounted single-seat driving position to go along with the full roll cage. Driver containment is handled by a Toora Racing seat and a set of OMP race harnesses while a Sparco suede-wrapped steering wheel is used to shuttle the Bug through the turns and Tilton pedal assemblies are used for the clutch and brakes. Grégoire fabricated the throttle system himself to work with the VW system in the car.

Fun Cup cars are built for racing as a single seat car with a center drive position and serious roll cage to keep the driver safe should something go wrong at speed. The Toora CE race seat and OMP race harness work together to make sure the driver stays comfortably and securely seated throughout the entire ride! Tilton clutch and brake pedals with individual master cylinders for the clutch, front and rear brakes are fully adjustable to provide the driver with excellent pedal feel while Grégoire fabricated a large throttle pedal to work with the VW TDI throttle assembly mounted under the front hood. Steering is handled through the 3-spoke Sparco suede covered steering wheel while the molded carbon fiber dash panel houses all of the necessary switches for operating the car. Grégoire was on a tight budget so rather than using an expensive race display he opted to use a Samsung tablet with Autosport Labs RaceCapture data acquisition system to monitor and log all of the car’s vital functions.

The lightweight composite body panels are easily removed and tilted to make working on the car simple and accessible. Under the 1-piece front hood, you will find the steering linkage, Optima Yellow-Top battery, brake and clutch fluid reservoirs, Fuel Safe fuel cell, Mishimoto radiator, and Frozen Boost heat exchanger.

The 1-piece rear body shell tilts back away from the car to reveal the modified VW TDI engine and transaxle. Fun Cup builds the racers with a square-tube fabricated chassis with Eibach coil-over struts on all four corners. As he has continued to develop and race the car Grégoire has upgraded and modified the chassis as needed to work with his particular setup and configuration.

Normally when we’d see a wing this size on a car this small we would make fun of the owner for their “Fast and Furious” stylization that is surely more style than substance, but in this case the wing is indeed installed on the car by the Fun Cup design team to improve handling and create additional downforce to keep it planted on the road. When cornering at high speeds on the “Race to the Clouds” with sheer drop-offs on either side of the narrow road it is important to have as much downforce and stability as possible. Grégoire is planning to replace the current wing with a new design before the next Pike’s Peak race looking to install one that is more effective aerodynamically with less teen-racer looks.

We caught up with Blachon as he blasted down the strip at the Crossville Dragway. Since that night, he has continually refined the car and has run a best pass of 7.4461-seconds at 96.51-MPH in the 1/8-mile. He expects to be in the 6s after he gets the car back on the track when the COVID-19 Pandemic clears.

After about a year building the car, Grégoire teamed with WRC driver Manfred Stohl putting him behind the wheel at the 2018 Pike’s Peak International Hill Climb. Manfred qualified the Boxeer Fun Cup racer with the fastest diesel time ever recorded on the mountain and looked forward to race day, but a massive hail storm hit and officials closed the top half of the course leaving the team with a half course run.

They vowed to return with a vengeance in 2019 and qualified yet again. Unfortunately, snow and hail canceled the race for them once again. Grégoire and the Boxeer team looked forward to challenging the mountain in June of 2020, but the COVID-19 pandemic has caused the organizers to reschedule the race to August 30, 2020. Hopefully, we’ll be able to see them take on the mountain and set a new diesel record this year, if not we’ll be cheering them on for 2021!

With WRC driver Manfred Stohl behind the wheel of the Boxeer Fun Cup racer it is ready to attack the mountain in the “Race to the Clouds”!

About the author

Chris Tobin

Chris Tobin has been interested in motorsports since before he could legally drive. He has built, driven and raced just about everything from scale RCs to motorcycles, cars, and trucks on the drag strip and off-road.
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