I have always wondered about this and its true impact on dyno plots.

with all the storys of putting it in cups of hot tea etc its always made me curious how much difference does it really make to din or sae corrections.

well I now have a bit of data.

my r33 was dynoed on a dynapack, temp sensor just hung in the dyno cell and recorded 563.3 hub power, then din correction took it to 561.9 so basically took a tiny bit of power away due to the temperature approx. 23d.

my same car in the same tune was dynoed previous to me owning but by the same dyno and operator (who are very good btw) the only difference was the temp sensor was under the bonnet (which I guess some may say is more representative as after all its all about engine intake air temp) but anyways it measured 536.6 hub power then din correction took it to 583.5 !

those 2 senarios went from taking away 1.4 hp to adding on 46.9 hp ! the only data I don't have is the temp reading of the probe for the old run but im guessing in the 40 - 50d area

and that's with no fugeing anything just 2 genuine dyno runs just with the temp sensor at ambient temp in the room or under the bonnet wether bonnet was open or shut again I don't know.

this is all without even considering any tcf to guesstimate flywheel power.


by no means a precise scientific comparisons but it is apples for apples and shows the difference a little temp change has on dyno readouts.