I see lots of guys talking about hp after dyno testing. After doing it myself I realised that the calculation of hp is not constant. When testing yesterday the guy had to put in some numbers in advance about how many horses you "loose" in the gearbox. He told me that you loose different amount of hp in different kind gearboxes, so it will not be accurate. My Express engine with 1,2mm flycut heads and dual 28 pci's with 95" main jets and 180" air jets, dynoed 27 hk on the wheels. As I was told, the actual amout of horses is between 33-36. Just perfect if you want to drive in steady 90 km/h, even uphill :-)
