ATTENTION: This site has been created as a public webpage where I can post information about my Audi S4. You will find links to various topics about this automobile. All opinions and statements are purely my own and should not be taken to be anything authoritative or definitive. Follow this link to read my philosophy on modifications.
Copyright 2003-2005.


































page 2

A couple interesting things came out of this comparison. I had originally estimated my stock car might make an additional 20 whp with the AWE DP's and Supersprint exhaust. But as it worked out, if my APR Stage III kit were to produce APR's advertised numbers, then the dyno correction factor (drive train loss) would result in my stock car creating 310 crank hp. This seemed very unlikely, but I decided to go fourth accepting this assumption. If my car and APR's car produced the same peak chp numbers, by integrating the hp curve from 2000-6500 rpm I would be able to determine if the overall power produced by the two cars was equivalent. I did a simple numerical integration (trapezoidal rule) breaking the curve up every 500 rpm. The result showed my car to be down 5% in crank hp, as compared to what this kit should make, and that was assuming my peak hp was equal to APR's advertised 412 hp. A more realistic drive train loss correction factor, netting my stock car 280 chp and Stage III setup 385 chp, would result in my car being down 11% in total power from what APR advertises for the kit. (GRAPH)

[From here forth I have changed some of the names of those involved to protect their identity.]

On May 16th I called Streetwerke and spoke to Tonto, he asked if I had ECUx and that they really needed to see some data since they didn't have the car available to them. A bit exasperated since I had sent them my VAG-COM data three weeks prior, I informed him that I used a VAG during the dyno session and that I had previously sent The Lone Ranger a link to my results. He asked for me to send the link to him and he'd look at it and talk to APR about it later in the week, since they were going to be coming out there.

While I was waiting for an answer from Streetwerke/APR I began to scour through the Audiworld forum for posts about the APR Stg3 kit on H-box cars. What I learned was not encouraging. It became clear that the H-box had been a poor performer with the APR code every since the beginning. A 2003 dyno test between an AMS chip and APR chip on the same H-box S4, using the supposedly better APR M code, showed a significant difference between the two, with the APR chip being outperformed by the AMS code on 91 octane pump gas. The results of another S4 owner from the drag strip and FATS tests further supported the conclusion that the H code did not perform well. My own results served to solidify my belief that the APR H-box code was behind the mediocre performance my car was demonstrating. I also came across the following quote from Jason (President of Streetwerke) in March of 2003 regarding the dyno comparison between AMS and APR with APR's M code on an H code car: "I think it was the right choice though, as the M code does feel better than the H code. 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." It would seem that over two years later APR still has not got around to addressing the issues with this code.

The APR Stg3 owners that I contacted made a couple of recommendations of hardware checks, such as verifying the orientation of the RS4 injectors, and checking the RS4 fuel pump for a modification to the hose. While checking the injectors I noticed that the RS4 MAF did not appear to be well sealed with the Airbox. Closer inspection revealed some missing fasteners. Streetwerke informed me that the kit did not come with these screws. Hard to imagine this, so I ended up going and buying the screws on my own to complete the kit. These missing fasteners led me to discover a problem with the other side of the MAF housing. The accordion hose and MAF did not make a smooth transition due to part of the accordion hose being folded over inside the tube.

I inquired with Streetwerke about the fuel pump, and they informed me that the RS4 fuel pump I had received had been properly modified.

My attention was now focused on getting the proper code into my car. Whether this was APR correcting the problem with their code, or finding another tuner to supply the chip for my vehicle.

May 24th I called Streetwerke to find out the results of the meeting with APR. I was informed that only APR Sales representatives had come out so they did not know anything more than before. They anticipated later in the week to know something more.

On May 26th I called Streetwerke again to see what they knew. I was told that my information had been forwarded to Hoss at APR.

May 31st. Tired of getting absolutely no answers about the data I had provided them and seemingly no effort on their part to get answers, after five weeks of dealing with Streetwerke, I contacted APR directly. I got a hold of Hoss and asked him what they had thought of my results. Hoss knew nothing of my situation or any information coming to them from Streetwerke. So I sent Hoss my information. This ended my efforts to work with the company that had sold me the kit, Streetwerke. It seemed that having sold me the kit and receiving payment, they no longer had any incentive or desire to assist me.

June 1st, I called APR and asked Hoss what he thought of the data. He hadn't had the chance to look at it, but said he would call me later in the day to discuss. I never got a call back. During my drive home I hooked up a VAG-COM to check my Knock Sensor activity. I checked for any fault codes and found that one had popped up, 18048 Internal Control Module (EEPROM) Error. I sent an email to Hoss notifying him of this and asking if he had any idea what it meant.

June 2nd, I called APR and spoke briefly with Hoss. He asked if it would be all right if he called me later and I agreed. Hoss called back in the evening and I described for him what it was about my results that I found unusual. He agreed that the results did seem odd, and he suggested that we try putting the M code on my spare ECU to see if that would help to correct the situation.

June 3rd, Friday, I sent my APR coded Stage 2 ECU to APR for modification.

June 6th, Monday. I received confirmation that the ECU was delivered to APR.

June 8th, I wrote to Hoss at APR inquiring about my ECU that had been delivered to them on June 6 for a Stg3 upgrade and M code install. He wrote back stating the ECU would be shipped back the same day and he would have a tracking number sent to me by the end of the day. I did not receive a tracking number.

June 9th, the upgraded H/M ECU was delivered along with ECUx, so that I would better be able to collect data on my next dyno session. I wrote to Hoss and informed him that there was no cable for the ECUx, and I did not believe my ISO-COM VAG cable would work with ECUx.

June 10th, Hoss wrote back stating he would be out of town the remainder of the day and the following Monday. He also thought the VAG-COM cable would work. I contacted someone that I had been corresponding with about my situation and mentioned that I still did not know what was installed on my M-box ECU. He offered to provide me with the T-box APE file. Since the M and T are interchangeable I accepted and loaded that into my ECU so it would have time to adapt.

June 13th, I wrote to Hoss at APR and informed him that after testing I had established that the ISO-COM cable did not work with ECUx. I also let him know that Friday of that week I had scheduled a dyno session, contingent on me getting ECUx to work. I also asked what information they would like me to log on the dyno. I also asked for the APE files for the M and H coded ECUs in addition to the appropriate adapter to connect my home programmer to the new ECU. As well, my M coded ECU had not come back with a listing of what programs had been installed and I needed to know what was on it.

June 14, I called APR at 11 a.m. and left a voice message for Hoss. Two hours later I had not heard back so I called again, did not get him, and left another voice mail. Two more hours later I had not heard from APR so I called again. This time I was able to speak with Hoss. He said he was busy as the moment but would get the ECUx cable in the mail and would call me later. He did not call back, but I received a UPS tracking number via email.

June 16th, I received a USB cable for ECUx but was still encountering problems getting the software to communicate with my car. I wrote to Hoss telling him of the situation and cancelled my dyno session. I also called APR and left a voice mail for Hoss. Later in the day I called and spoke to Little Joe at APR and he gave me some suggestions for getting ECUx to work. I tried them and succeeded in getting the software to run. I then rescheduled my dyno session for the next day. That afternoon I received an email from Hoss with some current drivers for ECUx.

[continue page 3]

PREVIOUS PHASE: Implementation