On paper, BMW's N54 turbo inline six was a tuner's dream. Direct injection, front-mounted intercooler and twin turbos, all attached to BMW's legendary drive dynamics. Most figured a simple software upgrade would make big power for very little cost. But it quickly became clear it was going to take considerable time and resources to penetrate the Siemens DME's defenses in order to manipulate the MSD80/81 code. This left some to develop external piggyback devices, but these simply acted as blinders, tricking the computer into thinking it's doing one thing when it's really doing something else. Now, GIAC has released its Stage 1 flash, and we just had to test it.

Vehicle Data

Engine: 3.0-liter I6, turbocharged and intercooled
Transmission: Six-speed automatic
Mileage: 44,908
Current modifications: Miro CSL Replica wheels, 8.5x19 (f), 9.5x19 (r)
Dyno Data Mustang MD-AWD-500 in 2wd Mode
Ambient temp: 80°F -86°F
Test gear: Fourth
Test octane: 91


Peak power:
265 hp @ 5550 rpm
Peak torque:
284 lb-ft @ 3175 rpm
Temperature: 80° F
Humidity: 24%

Test Notes
The baseline and all subsequent testing were performed on the same day, utilizing the same tank of 91 octane fuel. All quoted horsepower and torque numbers are measured at the wheels. It's also important to keep in mind that the properly calibrated "Mustang" dyno produces more accurate real world horsepower and torque numbers. While these numbers might seem low when compared to figures gathered from a Dynojet, what's important is the differences between each dyno run. Those differences are what we use to validate the manufacturer's horsepower and torque claims.

Test 1

Peak power: 313 hp @ 5,500 rpm
Peak torque: 331 lb-ft @ 3,175 rpm
Max power gain: 60 hp @ 6175 rpm
Max torque gain: 63 lb-ft @ 4250 rpm

Installation time: 45 minutes
MSRP: $800

• OBD port flashing allows the ECU and harness completely unmolested
• Increased throttle response and smoother power transitions
• Increase rev limiter to 7200 rpm
• Speed limiter is removed in the DME
software (not by altering vehicle speed sensor data) leaving ABS and DSC functions unaffected
• DME receives accurate data from the engine sensors, giving the ability to be more proactive instead of reactive, allowing DME to deliver the proper amount of fuel, cam and engine timing based on real world conditions
• 100% reversible

• GIAC flashloader technology not available yet

Test Notes
Even though this '07 had been to the dealership on more than a dozen occasions it had never had any software updates done, even when they replaced the fuel pump. So instead of the spending the standard amount of time to flash the vehicle, it took an additional two hours to update the necessary systems to accept the later software version. We upgraded to the later software because BMW had made several beneficial improvements to overall drivability, making a better software base for Stage 1 recalibration.

The boost data was generated using a boost line attached directly to intake manifold then attached to an externally mounted 3bar GM style MAP sensor with a 0-5 volt analog output range that sends a signal that was then converted by the dyno Powerdyne software.

Test 2

Peak power: 311 hp @ 5950 rpm
Peak torque: 330 lb-ft @ 3125 rpm

Parts: X-pipe, right and left axle pipe, muffler assembly with 3.5-inch round tips, 2.38-inch and 2.50-inch muffler clamps, vacuum plug
Tools: T50 torx bit, 15, 18 mm and 5/16-inch socket, extension, ratchet, WD-40, tape measure, reciprocating saw or pipe cutter
Installation time: 1-1.5 hours

• 2.5-inch fully mandrel bent stainless steel tubing
• 21-pound weight savings over the stock system
• Merge X-Pipe is designed to create a vacuum between the right and left exhaust pipes, increasing exhaust gas velocity
• Merge X-pipe designed to deepen sound while reducing droning
• Borla Million-Mile Warranty offers replacement parts if the product has any defects in materials and workmanship for 1,000,000 miles

• Cutting of the stock system (not a Borla design problem) since factory system is one piece from the downpipes back and includes two catalytic converters; the only way to legally swap out the cat-back portion is to cut it
• Slip-joint construction makes installation a bit tricky
• Lack of sealing compound for slip-joints made eliminating small exhaust leaks difficult, requiring several adjustments

Test Notes
We let the exhaust cool for a while before we swapped it out, and by the time we returned to the dyno room and recalibrated the dyno, the outside temperature had increased to more than 100° Fahrenheit, and the dyno room had had increased to 86°.

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