2007 Audi A4 Quattro - Proven

The Carbonio intake system has a factory-like appearance when the carbon fiber cover goes on. The install took BHR technicians about an hour.

The Carbonio intake system has a factory-like appearance when the carbon fiber cover goes

Some may wonder how this is possible. Remember, a heavy car with an automatic transmission is reliant on low-end torque to get out of the hole, as opposed to a manually shifted car that can launch at 4000 rpm. Off the line is where the stock A4 really suffers, but these tremendous low-end gains fixed that.

APR's 100-octane setting takes it to the next level if you can stomach the $6 per gallon ticket for this joyride (a 104-octane program is also available). With several more gallons of race fuel in the tank, the car was given another 15-minute adaptation period. On race fuel tuning, the car manages 203 AWHP and 230 lb-ft of torque, plus a whole second off the quarter-mile thanks to the 60-hp gain from 3500 to 5300 rpm.

Back on the road, the power difference is night and day between stock, 91, and 93 programs. Again, the most noticeable gain is when pressing the throttle from a standstill. When we tried the 100-octane program, it was just gravy, but we don't know if we can justify the doubled fuel prices for those extra few ponies over the 93 program. With a bigger turbo, however, the power difference between 93 and 100 would potentially be greater.

As one of APR's Midwest distributors, BHR was also responsible for loading up our different software programs.

As one of APR's Midwest distributors, BHR was also responsible for loading up our differen

Speaking of turbo sizing, the Audi 2.0T's is tiny, giving instant torque most everyday drivers would want, especially in an automatic. But, at one bar of boost, it's pretty much taxed, obvious by the diminishing returns in the top end. And after starting each dyno pull with an 88- to 91-degree (F) intake temperature, we were left with 130-degree-plus intake temperatures at the end, even in stock trim. Suffice to say a good water injection program would help. Even better would be a larger turbo. Guess what? APR has one. We'd expect to see the K04 turbo upgrade deliver well over 220 AWHP on 93-octane, hopefully with lower intake temps to boot.

Note: Gains for the 93-octane program over APR's 91 peaked at 18 hp and 19 lb-ft at 5000 rpm, while the 100-octane program peaked an additional eight hp and nine lb-ft of torque at 4880 rpm over the 93 program. For those living in areas with no 93-octane available, you'll need to find 100-octane unleaded racing fuel to run the 93 program. Since the A4's fuel tank capacity is 18.5 gallons, mix in four gallons to a full tank of 91, or 2.5 gallons to a full tank of 92 to get the effective 93-octane rating.

Audi 2.0T Quattro Automatic

Acceleration runs were done using the standard 'throttle and go' street method. With a little power braking on the line, though, we lowered our zero-to-60 mph time to 6.5 seconds, and mustered up a 14.8-second pass at 90 mph on the 100-octane setting on the first try.