Since 1997, modifying the ECU code of a turbocharged A4 has been the quickest and easiest way of coaxing 30 to 40 percent more horsepower and torque. This was instrumental in increasing the A4's enthusiast popularity because its factory-rated 150 hp was pretty pathetic for a midsize sedan in 1997. Still, over the years Audi has employed several different methods to prevent alterations to the ECU. In the past these were easily bypassed, but recent efforts, such as advanced flashing algorithms, checksums, and RSA encryption have made upgrading software difficult.
For more than 17 years, GIAC has been developing tools and equipment that can penetrate the most complex ECU defense systems. With the release of the 2010 A4 2.0 TFSI with Audi's most advance ECU encryption, GIAC's answer was its Stage 1 upgrade with full switching capability.
Graph 1: Baseline
Vehicle Data
Engine:
2.0-liter I4, dohc, 16-valve, direct injection
Transmission: Six-speed manual, all-wheel drive
Mileage: 4,646
Current modifications: None
Dyno data: Mustang MD-AWD-500 in 4WD Mode
Test octane: 91
Test gear: Fourth
Baseline
Peak power: 172 hp @ 4425 rpm
Peak torque: 213 lb-ft @ 3925 rpm
*All horsepower and torque figures quoted are at the wheels
Temperature: 76° F
Humidity: 18%
Test Notes
The baseline and GIAC Stage 1 91-octane software tests were performed on the same day utilizing the same tank of 91-octane fuel. All horsepower and torque numbers are quoted at the wheels. It's also important to keep in mind that the Mustang dyno, when properly calibrated, produces very accurate power and torque numbers. While the numbers matter, it is the differences between the runs that help prove or disprove the validity of the manufacturer's claims.
Graph 2: Baseline vs. 91-octane Software
GIAC Stage 1 Software
91 Octane
Test 1
Performance
Peak power: 201 hp @ 5075 rpm
Peak torque: 254 lb-ft @ 3425 rpm
Peak power gain: 36 hp @ 5350 rpm
Peak torque gain: 49 lb-ft @ 3425 rpm
Temperature: 78° F
Humidity: 18%
Parts: OBD Port Flash
Installation time: 45 minutes
MSRP: $550
The boost data was generated using a boost line attached directly to the intake manifold t
Pros
• OBD port flashing leaves the ECU and harness completely unmolested
• Increased throttle response and smoother power transitions
• All factory safety protocols remain intact
• Boost, fuel and engine timing calibrations are based on real world conditions and testing
• 100 percent reversible
• Available in both 91 or 93 octane versions at no additional cost
• Speed limiter increase in sixth gear only
Cons
• 7000-rpm rev limiter only available as a free option on vehicles equipped with a manual transmission
Test Notes
None
Graph 3: 91-octane Software vs 100-octane software
GIAC Stage 1 Software
100 Octane
Test 2
Performance
Peak power: 215 hp @ 5295 rpm
Peak torque: 254 lb-ft @ 3045 rpm
Peak power gain: 14 hp @ 5310 rpm
Peak torque gain: 15 lb-ft @ 4905 rpm
Temperature: 77° F
Humidity:16%
Installation time: With 100 octane in the tank, 30 seconds with GIAC Flashloader
MSRP: $7.99 per gallon (est.)
Pros
• Prevents excess timing retard that can reduce horsepower
• Helps maintain power in extreme temperatures
• CARB Approved Street legal 100 octane designed for street and track use
• Contains no metal compounds that can destroy catalytic converters or oxygen sensors
Cons
• A pricey addiction
Test Notes
The tank was still a third of the way full of 91 octane when we went to start the second test, even after extended test drives, so the 100 octane test was not performed on the same day. To ensure complete accuracy of the 100-octane results, this test was performed the very next day using three gallons of VP100.
GIAC Flashloader hand-held (Options)
Installation time:
If purchased separately, the upgrade takes approximately one hour
MSRP: Flashloader Handheld $150
Programs: Race $100*, Valet $50*, Stock $50*, Privacy Firewall $100*
*Purchase of GIAC Stage 1 Software