The Audi S4 has done a rare thing in the automotive world; it has gone from being a highly sought after, often unobtainable sports sedan to one that dealers can barely give away. I remember a time when the B5 S4 was all enthusiasts could talk about, and even after being out of production for over a decade the B5 is still the most desired. So why did the S4 fall from grace? Was it Audi’s bad engine choices? Elimination of an amazing color palette? Addition of expensive packaging options or non-distinctive styling? In my opinion, the B5 S4 2.7T was successful because it was tunable. Even though subsequent models had more power and advanced technology, they lost their tunablity and zest that defined the S4. The engineers at GIAC hope to rekindle the relationship that enthusiasts had with the S4 product line with their latest software solution for the B8 S4 3.0T (supercharged).

Vehicle Data

Engine: 3.0-liter V6, dohc, 24-valve, supercharged
Transmission: seven-speed dual clutch
Drivetrain: quattro all-wheel drive
Mileage: 21,633
Current modifications: AWE S-flow intake, AWE resonator exhaust with downpipes, H&R springs, Rotiform SNA 9.5x19 wheels, Michelin Pilot Super Sport 265/30 tires

Dyno Data
Dyno type: Mustang MD-AWD-500
Transmission test gear: Fourth

Performance
Stock (no modifications)*
Peak power: 297 hp @ 5468 rpm
Peak torque: 295 lb-ft @ 4834 rpm Baseline (w/ current modifications)
Peak power: 320 hp @ 5770 rpm
Peak torque: 310 lb-ft @ 5000 rpm

Test Notes
The S4 baseline, with AWE intake and exhaust, and GIAC 91 octane ECU flash dyno runs were performed on the same day, utilizing the same tank of 91 octane fuel and stock wheels. All horsepower and torque numbers are quoted at all four wheels. It is 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 or Dynapack, what is important is the differences between each dyno run. These differences are what we use to verify the validity of the manufacturers’ horsepower and torque claims.

* The stock dyno run was performed two months before the baseline test and is here for comparison purposes only.

GIAC ECU Flash

Test 1
GIAC Pump Mode 91 Octane

Performance

Peak power: 386 hp @ 6736 rpm
Peak torque: 337 lb-ft @ 4030 rpm
Max power gain: 76 hp @ 6754 rpm
Max torque gain: 32 lb-ft @ 3890 rpm

Install Process: Initial Bench Flash, subsequent updates via OBD port
Installation time: 45 minutes
MSRP: $1,200

Pros

  • Increased throttle response and smoother power transitions
  • Speed limiter is raised to factory redline in final drive gear
  • 100% reversible
  • Flashloader handheld switcher with Stock, Race and Valet modes
  • Optimized air/fuel ratio
  • Eliminates supercharger lag in lower rpm range

Cons

  • None

Test 2
GIAC Race Mode 100 Octane

Performance

Peak power: 412 hp @ 6740 rpm
Peak torque: 356 lb-ft @ 4836 rpm
Max power gain: 29 hp @ 6588 rpm
Max torque gain: 27 lb-ft @ 5098 rpm
Price: $7.59 per gallon for fuel, Race Mode 100 Octane included in original purchase price

Test Notes

The vehicle still had a quarter tank of 91 octane when we started the 100 octane test with VP fuel despite an extended test drive after the GIAC 91 octane dyno run. I was unable to deplete the tank to do the 100 octane test on the same day and to ensure complete accuracy of the 100 octane results.

Conclusion

The supercharged 3.0L V6 engine found in the B8 S4 feels more like a four-cylinder engine with an oversized turbo. I was always under the impression that the main benefit of supercharging is instant response. Yet when you drive a stock S4, there is a lag and you have to wait until 3000 rpm for the S4 to come alive. And depending on what gear you are in the engine feels like it is bogged down, like a horse that just finished its last Kentucky Derby and was on its way to the glue factory. From what the engineers at GIAC tell me, it’s the software and not the hardware to blame. For some odd reason, Audi has designed its software to bleed off most of the boost in the lower rpm range.

With the GIAC software, the B8 S4 S-tronic was completely transformed. The lower rpm boost lag was nonexistent in both Drive and Sport modes. No longer did it seem to hunt around for the right gear under acceleration, and when it downshifted from D6 to D3 at 1800 rpm, the motor pulled solid all the way to redline.

Part throttle response was dramatically enhanced. I no longer had to mash the throttle, downshift and yell giddyap to get the car moving. The most amazing part of the GIAC software was its ability to refurbish and restore my driving experience and overall perception of the B8 S4. As a side note, or a top note if you will, the AWE exhaust sounds amazing. The symphony of sounds that accompanied my ride in the B8 made it a day at the races and the S4 neighed like a true thoroughbred. Costs Summary GIAC Software $1,200

Costs Summary
GIAC Software $1,200

SOURCE
AWE Tuning
www.awe-tuning.com
GIAC
1350 Reynolds Ave, Suite 106
Irvine
CA  92614
949-724-0014
www.giacusa.com
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