I know that, but like someone on this forum stated before dyno is just a tuning tool. Just because you make a certain power on 2 wheels and then throw the power to 4 wheels doesnt mean your timing and fuel map gonna change. You hp will. Mustang dynos are closest to simulating load, but the air you get on a dyno from a fan will never compare to you driving on the street. Try putting your hand out your window at 60mph and then put your hand in front of a fan used on the dyno, no comparison. The ecu does look at load, but not like the ecu is gonna say, uh its 4wheels now lets pull some timing and fuel. That is why buschur was able to still use a 2 wheel dyno for a bit, I didnt see any cars blow up because he was using a 2 wheel dyno and the put the power to 4 wheels, but of course it was very inconvienent to disconnect the drive shaft.

 

not recommended to use 2WD dyno on 4WD cars... better to travel a little bit and use the 4WD dynojet...