Stage III APR STG3 History


A brief history of the APR Stage III Kit

June 23, 2002 – APR website lists their Stage III kit for sale. Dyno plots showing representative horsepower and torque are posted with a date of April 19, 2002.

February 5, 2003 – Discussion on Audiworld centers on rumors of updated software for the Stage 3 S4. The following is posted by Brett/APR on Audiworld.

“Clarification on this…
From a tuning standpoint, there has been NO revision of the APR Stage 3 software since version 1.2 was released in September 2002.

However, we have recently discovered a problem with particular compiles of the M, H, and T S4 Stage 3 V1.2 software. The affected APEs are the first build of the version 1.2 Stage 3 software that uses the new EMCS routines (released with Anti-Theft). These APE files would have a build date from early November 2002. The problem was caused by a code-overlap memory conflict between the newer larger EMCS functions and certain Stage 3 specific routines. The symptoms of this problem include under boost, lower overall performance, and automatic swapping to the low boost profile.

To remedy the problem, simply use the build of V1.2 dated pre-November 2002 or use the latest build of V1.2 dated late January 2003. THIS PROBLEM ONLY AFFECTS STAGE 3 S4 H, M, T, ECUs RUNNING THE SPECIFIC VERSION OF THE CODE DESCRIBED ABOVE”.


February 2003 – A flurry of discussion continues on AW between owners of the different ECU’s about the performance difference between the various boxes running APR’s Stg3 code.

March 2, 2003 – Jason Leone, working for an APR distributor, comments on MarinS4’s comparison of the numbers his Stage 3 kit made running APR’s software, M code on an H box, versus AMS, on 91 octane pump gas. Dyno results show AMS software outperforming APR software. Jason comments that “APR does have some work to do, and I have voiced my opinion to no less than four APR employees in person. The S4 should be back on the dyno in about 4-6 weeks for further tuning. We’ll see.”

March 5, 2003 – Post exchange on Audiworld about APR’s code:

“Have you bugged APR into updating the H-box stuff like the M-box stuff anymore?
It bothers me that only M-box people have the stuff that runs good and you don’t. Even though I don’t own a Stage III kit, that just isn’t right. That’s too much money to not be happy and have to go else where for support. Hopefully they’ll have it soon so you can at least have it…. whether or not you want to use it, ya know. You’ve already paid for it so you deserve the good stuff.”


“After 7 months of trying I have run out of breath. It was much easier to just buy something else. I have put 11,000 miles on my stage 3 with the bad APR software. Not sure how many miles I will keep the car so why wait. I think after 11,000 miles and 7 months of waiting I had enough.

I wonder if I can lemon law my APR software. I can’t think of anyone that would tolerate this from Audi if it were OEM related.”

March 29, 2003 – In response to a post asking if all the Stage III code had been updated, Jason@ND responds with “Well, the Stg3 programs have not all been retuned yet. Soon though. Stg1/2 on the dyno now.”

May 14, 2003 – In response to a question about APR updating their Stage I code Jason@ND replies “Not at all, we’ve been beta tuning for over a month now on all S4 code.”

July 3, 2003 – Posted by MarinS4, “APR Stage 3 software update for A & H boxes…
Spoke to APR yesterday. No ETA on corrected software. Jeremy stated that they are working on more important stuff. The poor performance issues on A & H boxes are well documented. Both Andy and I experienced a 40-whp increase when using AMS over APR. When I spoke to Brett in February he acknowledged the problem as well. Yes I have been very happy with AMS but I paid top dollar for APR software and expect it to work as it does for the M & T boxes. I think I have been very patience waiting for an entire year. I want a refund for the software if they are unwilling or unable to fix it! I have also forwarded this on to our company attorney to see what our options are. This is plain false advertisement since I purchased a “kit” that is not even close to what they claim.

January 24, 2004 – MarkP posts dyno charts after testing APR beta v1.6aa Stage III 93 octane software.

September 25, 2004 – MarkP posts dyno charts from APR beta AF Stg3 93 octane software.

October 22, 2004 – MarkP posts dyno charts from APR beta AC Stg3 104 octane software.

November/December 2004 – APR’s B5 S4 is sold to GMP Performance of Charlotte, NC.

May 31, 2005 – I contact APR to express my disappointment with the performance of their H box Stg3 kit.

June 2, 2005 – APR representative suggests trying to recode my H code ECU with M software to see what changes result.

June 17, 2005 – H box S4 is dyno’d with T code, producing substantially different horsepower and torque curves.

August 3, 2005 – APR agrees to retune their H box code using my S4.

September 22, 2005 – Stephen Hooks of APR posts to the B5 S4 forum on the Audiworld website in response to a request for updated code from an APR Stage III owner, that “It just so happens that we have a B5 S4 Stg 3 in next week for more code development. We do our best to keep development going on all chassis!! We should have some updated code when the code work is finished.”

September 25, 2005 – My S4 is delivered to APR to serve as a test bed for code rework

October 18, 2005 – Stephen at APR posts again to the AW forum updating the status of their code work. “Update on New APR Software for APR B5 S4 Stg 3. We are currently deep in retuning the S4. Stay tuned for updates… : )”

Which prompts the following question: “What brought this about? I got the feeling that APR’s software was pretty much in its final form now”. To which Stephen replies “We are never satisfied with things. But there is only so much time to work on each project and we also have to stay ahead of the game on all new cars. We have received much customer feedback and we want to address each and everyones concerns. I am sure the new software when released will be very very good.” Stephen/APR

November 4, 2005 – APR completes tuning rework with my car. Works to verify like performance on all ECU’s.

November 16, 2005 – APR releases version 2.0 of their Stage 3 software.

Audi B5 S4 Information and Testing