Motorsports Monday: 2004 BMW M3 GTR Replica

In 2001, BMW wanted to race the new E46 M3 in the Le Mans GT series. But in order to really be competitive, it needed more power – after all, it would be racing the likes of the Corvette C5R, the Porsche 911 GT3, and even Ferraris. As stout as the S54 was, BMW opted to stick a V8 into the E46. Not only did the V8 produce more power, but a look under the hood revealed that it moved the weight back – far back – from where the inline-6 would normally hang. Run by Schnitzer in Europe and PTG in the U.S., they were quite successful if often protested, and in 2001 the PTG developed car won the Petit LeMans in the U.S. and continued to win until 2005 in Europe. They also won the imaginations of BMW fans across the globe, with the the necessary road-going 380 horsepower GTR model a mythical beast of near biblical proportions. Some went a step farther, though, and made track ready weapons. To lower the M3 and be able to run massive wheels – like the 18×11 and 12″ variety of this particular replica – it required some work. Well, a lot of work:

CLICK FOR DETAILS: 2004 BMW M3 GTR Replica on eBay

Year: 2004
Model: M3 GTR
Engine: 3.2 liter inline-6
Transmission: 6-speed manual
Mileage: Not Listed
Price: $79,900 Buy It Now

Description

This car was built at Precision Chassis Works in Gilbert Arizona, and was #3 of 4, ALMS, GTR M3 chassis that were built to mimic the original BMW Motorsports/PTG cars. These cars were built based on one of the actual, original, GTR’s that was campaigned in ALMS. (coincidentally this car was also chassis #3 from PTG).The car features more detail than I can write, but I will do my best to cover the important things.

BODY WORK/CHASSIS
The car started out as a 2004 M3 with low miles and no collision history. The body panels are all carbon fiber, and are exact replicas of the original body work on the PTG car. The molds for these parts were literally taken right off of an original GTR. For those who don’t already know, this wide body package not only makes the car wide, but it also raises the wheel wells up in the chassis to allow for a lower ride height, and also allows for the use of a taller rear tire (rear tire size is 325/710/18). To make all of this possible and functional, drastic modifications had to be made to the chassis and suspension system. The front wheel wells were cut out and raised almost 2”. The rear wheel wells were also cut out and raised 3”. Changes to the chassis were also made to facilitate the custom suspension system in the rear. The cage in the car was made to duplicate the BMW Motorsports cage as much as possible, while still being legal for club racing without an FIA certification. The rear subframe mounts (now the differential mounts) were tied into the cage, as well as the front shock towers. The rear window and quarter windows are polycarbonate, but the windshield is glass for easy maintaince. AeroCatch hood pins keep the hood and deck lid closed. The car weighs in at just a hair over 2700lbs with no driver and a half tank of fuel, with a PERFECT 50/50 weight distribution.

SUSPENSION/BRAKES/WHEELS
Because of the low ride height, the suspension system was heavily modified to correct all of the geometry and make everything work correctly. This meant that the rear subframe was completely removed and we once again, copied what PTG had done on the original GTR’s. Because we had an original car to copy, all of the rear suspension geometry and design is exactly how PTG did it. We were even able to build a fixture, based on a set of original, cast aluminum PTG trailing arms, and manufacture our own tubular steel arms that operate exactly like the originals. To make all of this work, the chassis had to be modified to raise the trailing arms and the differential upward, just like PTG did, and new mounting provisions had to be fabricated. This also required that the driveshaft tunnel and rear seat pan had to be clearance for the driveshaft. A custom, bladed rear sway bar was also fabricated to match the bars that were on the original PTG cars. The front suspension received the custom, wide body, Bimmerworld lower control arms, which also incorporate roll center correction. The tie-rods are Ground Control and feature bumpsteer correction. The coil-overs are JRZ RS Pro with remove reservoirs. The brakes are a Brembo kit (4 piston front and rear) with 355mm front rotors. The brake booster has been eliminated and in its place, a custom, dual master cylinder bias box was added, and the factory brake pedal was modified to operate with the correct pedal ratio with a pair of Tilton master cylinders, and a Tilton cockpit adjustable brake bias knob. The brakes are cooled through carbon fiber brake ducts in the front bumper opening. The wheels are CCW monoblocks that are 18×11 front and 18×12 rear.

ENGINE/TRANSMISSIONS/DIFFERENTIAL
The engine is a stock S54 with perfect leakdown numbers. DINAN throttle bodies were added prior to the build. A TMS under drive pulley kit was installed. The transmission is a stock 6 speed, with a light weight flywheel and clutch package. The differential was sent to DiffsOnline and they installed their LSD along with a 4.10 final drive and REM treatment on internal components. The transmission is shifted by an AKG shifter. A custom engine oil cooler system and power steering system were added using Setrab oil coolers. A differential cooler system was also installed and also uses a Setrab cooler along with a Tilton pump. The engine is cooled using a Bimmerworld (C&R) aluminum radiator and custom expansion tank. Custom radiator ducting directs air through the radiator.

ENGINE MANAGEMENT/WIRING
The stock M3 engine management system was isolated from the rest of the chassis harness and modified to place the ECU inside the cockpit. An AEM Infinity ECU is used to control the engine, and was tuned for both 91 octane (310whp) and 100 octane (336whp) by DynoComp in Scottsdale AZ. A custom chassis harness was made from scratch, and a RacePak dash monitors the engine and provides datalogging.

EXHAUST/INTAKE
The exhaust consists of Euro headers that feed into a custom stainless steel, side exit exhaust system. The intake uses a stock air box with an AFE elbow and a custom intake tube with a dry element cone filter behind the carbon fiber headlight delete panel. The air box and intake tube are covered in gold reflective foil to reflect heat from the engine block and radiator.

SAFETY/INTERIOR
Besides the cage system, the car also features a new Racetech “halo” seat, Schroth 6 point harness, Safecraft 10lb Halon based fire suppression system, and a dual activation battery disconnect system. The dash is a custom carbon fiber piece that is amazingly light weight. A 24qt Cool Shift system is installed as well as an AllView mirror, and disconnect Momo suede steering wheel.

FUEL DELIVERY
The stock fuel system was removed, and an ATL, 32 gallon fuel cell was added in the trunk (which is sealed from the cockpit) using a custom fabricated fuel cell mounting system and enclosure, which feeds the Bosch 044 pump and 750cc injectors. An OEM fuel filter and fuel pressure regulator were used for easy service, and all fuel lines are -6 AN.

EXTERIOR
The exterior features a vinyl wrap, done in the Jeff Koons Art Car theme. Under the wrap, the exterior of the car is in primer, so if the next owner would like to paint it, it would be very easy to do.

This would make a GREAT GTS4

The development of these cars cost in the hundreds of thousands of dollars originally, but this car turns the race development down a few notches. There is no V8 under the hood, for example, but instead the original S54 and 6-speed manual remain from the remnants of what was a 2004 Silver Gray Metallic M3. Gutted, caged and tubbed, massive flares and aerodynamic aides have been attached which are more than the match for the S54. It’s not clear how much actual track time this car has seen, but it should be seriously potent on course, and the massive rubber will no doubt lead to low lap times. Couple that with the 32 (!) gallon fuel cell and you can embarrass your E9x friends all day long in what should be a much more affordable car to run than the original V8 GTR. To top it all off, the Koonz-inspired wrap from the E92 GT2 M3 is the perfect match for the race look. Opportunities to get into a car so developed are very few and far between, and building one yourself would be cost prohibitive. $80,000 is a lot of scratch for an E46 M3, but this is a pretty impressive one and a real PTG GTR would probably ask multiple times that amount. While not a factory build, this makes a compelling alternative to the expensive to run Porsche 911 GT3 996 models for around the same price.

-Carter