What follows is a summary of the results I observed from the software revision. These dyno runs were made on APR’s Dynapack dyno. A drivetrain loss of 12% seems to be reasonable for this dyno.
This dyno plot shows the difference between my old v1.2 software and the new, 2.0 software on 93 octane gasoline. In addition to a peak wheel HP increase of 40 wHP, now 386whp/439chp, the new software is much better throughout the rpm range.
|This chart shows the difference on 91 octane gasoline. New values are: 363whp/413chp.|
|This chart shows the difference on 100 octane gasoline. New values are: 447whp/508chp.|
|This chart shows the difference on 104 octane gasoline. New values are: 468whp/532chp.|
|After getting my car back I performed two 60-90 mph FATS runs. The time for each run was 3.75 sec., and 3.8 sec. This is a substantial improvement over my previous best time of 4.3 sec., recorded using M code software.Finally, during my trip home from APR I found the gas mileage to be better than on the previous software, having gained an average of 3 mpg for the entire trip, and one tank producing an average of 31 mpg.A couple of weeks later I attended a dyno day at AWE Tuning and got the following results on 93 octane gas. AWE applies a correction of 1.28 to their wheel HP numbers to obtain crank HP.
Having completed this journey how do I view my decision to go with the APR Stage III kit?
Despite the incredible frustration I experienced dealing with APR, and total absence of any recognition of my efforts on their part, I am happy with the product that we ultimately delivered to the APR customers. A year wiser about the Stage 3 tuning process, I’m very happy I didn’t try to go the homebrew route. The homebrew tuning process does get power results, but I’m very skeptical about long-term reliability. Broad brush elevation of timing tables, boost values, and leaning fuel can make power, but the manner in which it is being performed is a crude process that opens the door to problems which may manifest over time.
I also need to recognize a couple of members of the Audiworld forum who helped me throughout the ordeal. Hal_S4Shizzle was a tremendous wealth of information and always an email away for me to bounce thoughts off of. He also generously picked up the tab for my lunch during my trip home, when we finally had the opportunity to meet in person at his home. Gator(Al) provided additional motivation to keep pushing along, knowing he was another Stg3 H box owner and sufferer of that abysmal software helped keep my sights on the greater good of the effort. His appreciation of my efforts, during the process, helped to keep my spirits up when it seemed like I’d never see my car again.
Finally, to answer the big question, “Do I think obtaining the Stg3 kit was worth the cost and effort?” Definitely. APR has done a fine job, and the car now accelerates at a rate that is just plain stupid fast.