Bill: We're under no illusion that its perfect. However we worked on the assumption that as long as we run it on 98octane fuel, the management (which is designed to run perfectly well on 95) would handle any over advanced timing, with the fuel taking up the slack. Looking at the vagcom logs from the car, the highest knock retard logged is 8degrees. This is no different to a completely stock S4 running on 95 octane fuel. I can show you logs of a standard S4 running on 95 and 98 if you'd like to see this. The MAF and Fuelling may be "frigged" but the maf is underreading by 38%, and the injectors are 40% larger than stock, which for the most part will balance out. This can be seen by the fact that the Lambda multiplicative correction % is sat around 3, as opposed to some wildly high number. The N75 is completely under the ECU's control. AEB has no boost sensing, so the ECU is pushing the N75 duty cycle by itself to get to what it thinks is the correct maf values. Ideally the car needs some timing pulled out, and when it gets mapped, thats exactly what will happen. But given the values the ECU is pulling seem the same as a stock S4 running on 95, i cant see how they're dangerous?