Content > Masa's Audi A3

If there’s one thing we Finns usually agree on, it’s that the weather is never perfect. Either it’s too cold and rainy, or too warm and humid. Or too windy. Or maybe too bright or dark. This seems to be in our genes, and we just can’t help it. Recently it’s become clear that the same applies to cars too, especially the turbocharged ones.

For track use, my A3 is equipped with APR’s stage 2 ECU upgrade. As we are all law abiding citizens, and running with an upgraded engine software would be illegal on the public roads, obviously I have chosen the option of selecting between stock and tune software easily from the cruise control switch. A handy feature.

Anyhow. Some of us went and bought PerformanceBoxes earlier this year. As you might know, the box includes an engine power estimation feature, which is based on the cars weight and acceleration results. Although this is obviously an estimate only, we’ve found the results to be surprisingly accurate. And if nothing else, the differences between results on the same car should at the least be comparable.

We’ve had three trackdays at Ahvenisto this year that I’ve been able to attend to. The first one was on a clearly cooler day, and my lap times were around 1:37 (best 1:36.8). The two later ones were on much hotter days – air temperature close to 30c, track temperature probably somewhere around or even above 50c. Lap times on these days were on average clearly over a second slower, with 1:37.9 as the best one. Some of the difference can be explained by the fact that regular road tires don’t like the heat either, but it just doesn’t explain the whole difference – especially as ‘freaks with NA engines did not seem to suffer from the heat as much.

During the cooler weathers at the beginning of the summer, I measured an estimate of roughly 170kW from the wheels running with the APR software. With a 15% drive-train loss, this would equal around 270hp, which is in line with what the Stage 2 upgrade should provide. On the latest trackday yesterday, I repeated the measurement after a few fast laps. This time the box read 155kW. With 15kW less on the wheels, it’s no surprise that my laptimes have been declining.

An IC upgrade might be able to help with this to some extent, but somehow that seems like an overkill for the climate in Finland – the long term average temperature in Helsinki in July is still clearly below 20c, we’ve just had a bit of “bad luck” on our trackdays hitting the hottest possible days. And this is not really anything new – it’s a well known fact that turbocharged cars prefer cool air. I am just somewhat surprised with the difference being as large as it seems to be.