Innocence Lost – Turning a garage-queen BMW E92 M3 into a proper Time Trial car

By
Brett Becker
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It’s funny what racing does to the human mind. One minute we’re capable of making rational decisions and the next we’re tearing apart a pristine BMW M3 and turning it into a track car.

In The Doghouse Garage in Oxnard, Calif., is prepping a 2008 E92 M3 into a Time Trial car for competition in the SoCal Region. The owner wanted to use the car for Time Trial competition, with the understanding that he eventually would use it for racing. After some discussion, the owner and the folks at In The Doghouse Garage decided it would be best to do the full cage now rather than installing a roll bar, then having to tear that out to add a full cage whenever the customer decided to go racing.

“He was thinking about selling this car and going and buying an E36 or a Spec Miata, or a Spec E30, but he just got to the point where he already had this car, he had it lying around and asked us to build it into a racecar,” said Ben Wilkinson from In the Doghouse Garage. “He kind of went from, ‘Hey, let’s ease into this to all right, we’re just going to go full idiot on it.’”

The car is pristine, with just more than 20,000 miles on it. Initial plans call for mild modifications. ITDG installed D2 springs and triple-adjustable shocks with external reservoirs. Each adjustment has 36 different settings to fine tune suspension behavior. They sent the car out to Jim Pierce Motorsports in Torrance, Calif., for the cage work and to C&J Auto Body in Oxnard, Calif., to have the cage painted.

For now, it’s just a cage, D2 shocks and springs, Sparco seats, Schroth harnesses and nets and Sampson radios. Later on, ITDG will add sway bars and further chassis enhancements. The big challenges in building a modern BMW into a track car lie in the electronics.

“For right now we just want to get it out there and see what it’s going to do with its suspension till we kind of know more about what we need to buy,” Wilkinson said.

For example, ITDG left the stock steering wheel in place because of the shifter paddles for the SMG transmission. It also left in place the center console because of all the wiring and control modules it houses and because the iDrive rotary control knob is integral to so many systems on the car. Later on, when the car goes into full race mode, that will have to change.

“Normally what we do on a car is go through and reduce the wiring harness to the bare minimum,” Wilkinson said. “We haven’t done that yet due to the fact that we’re just trying to get the car on track at this point. That’s going to take probably 20 to 30 man hours of labor because we’re going to have to trace every wire straight back to the source, one at a time, because if you cut the wrong one on this car, you’re done.”

Here are the steps on the initial phases of the build.

Before the cage could be installed, In The Doghouse Garage gutted the interior, including as much of the wiring and as many of the control modules as possible.
Before the cage could be installed, In The Doghouse Garage gutted the interior, including as much of the wiring and as many of the control modules as possible.
Ben Wilkinson removes the interior door panel in preparation for removing the window glass and cutting the inner door panel to accommodate the roll cage.
Ben Wilkinson removes the interior door panel in preparation for removing the window glass and cutting the inner door panel to accommodate the roll cage.
As the gutting continues, a pile of trim begins to accumulate.
As the gutting continues, a pile of trim begins to accumulate.
One of the bigger challenges in building the E92 is all the wiring and electronic modules in the car. Knowing what you can safely remove is key.
One of the bigger challenges in building the E92 is all the wiring and electronic modules in the car. Knowing what you can safely remove is key.
Because of the paddle shifters for the SMG transmission, the car will retain the stock steering wheel for now. Likewise, the console remains in place to accommodate the iDrive knob and system.
Because of the paddle shifters for the SMG transmission, the car will retain the stock steering wheel for now. Likewise, the console remains in place to accommodate the iDrive knob and system.
The windshield needs to come out to be able to install the front A pillar supports on the roll cage. They often break when removed, but this one survived.
The windshield needs to come out to be able to install the front A pillar supports on the roll cage. They often break when removed, but this one survived.
As teardown continues, the electronic modules continue to pile up.
As teardown continues, the electronic modules continue to pile up.
The E92 is equipped with side-curtain air bags, which also need to be removed before the cage can be installed.
The E92 is equipped with side-curtain air bags, which also need to be removed before the cage can be installed.
Jim Pierce Motorsports in Torrance, Calif., installed the cage in the E92, which is now ready for paint at C&J Auto Body in Oxnard, Calif.
Jim Pierce Motorsports in Torrance, Calif., installed the cage in the E92, which is now ready for paint at C&J Auto Body in Oxnard, Calif.
The E92 cage is fitted with NASCAR bars on the driver’s side. They protrude into the door to give the driver extra protection in the event of a perpendicular collision.
The E92 cage is fitted with NASCAR bars on the driver’s side. They protrude into the door to give the driver extra protection in the event of a perpendicular collision.
The passenger side of the roll cage is a simple X brace, tied into the front and main hoops and the rocker panel.
The passenger side of the roll cage is a simple X brace, tied into the front and main hoops and the rocker panel.
The right corner of the main hoop is tied in with the diagonal roof brace and the tube that leads to the A pillar and both back supporting braces.
The right corner of the main hoop is tied in with the diagonal roof brace and the tube that leads to the A pillar and both back supporting braces.
The left corner of the main hoop connects the lateral diagonal brace, the rear support and the tube that leads to the A pillar. It’s also where the rear of the window net mounts.
The left corner of the main hoop connects the lateral diagonal brace, the rear support and the tube that leads to the A pillar. It’s also where the rear of the window net mounts.
Here you can see how the NASCAR bars protrude into the driver’s door and how the support hoops tie into the rocker panels.
Here you can see how the NASCAR bars protrude into the driver’s door and how the support hoops tie into the rocker panels.
Here you can see how the A pillar hoop ties into the rocker panel in such a way that it presents minimal intrusion into the driver’s foot well.
Here you can see how the A pillar hoop ties into the rocker panel in such a way that it presents minimal intrusion into the driver’s foot well.
After paint, ITDG begins installing the roll bar padding.
After paint, ITDG begins installing the roll bar padding.
Here’s another look at the rear of the cage and its supports.
Here’s another look at the rear of the cage and its supports.
The rear supports for the main hoop land on main frame rails that run fore and aft.
The rear supports for the main hoop land on main frame rails that run fore and aft.
Here’s another look at the NASCAR bars after paint and roll bar padding.
Here’s another look at the NASCAR bars after paint and roll bar padding.
ITDG’s Patrick Orozco begins disassembling the rear suspension to install the D2 triple-adjustable shocks and springs.
ITDG’s Patrick Orozco begins disassembling the rear suspension to install the D2 triple-adjustable shocks and springs.
Note the M-specific arm on the rear suspension.
Note the M-specific arm on the rear suspension.
Orozco uses an air-operated jack to raise the new shocks and springs into place.
Orozco uses an air-operated jack to raise the new shocks and springs into place.
Orozco buttons up the outside while Joey Moore attaches the shock from the inside.
Orozco buttons up the outside while Joey Moore attaches the shock from the inside.
Image courtesy of Brett Becker

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