As requested here is the graph of the temp differences between the GV Bonnet (Round 1 Time Attack) and OEM (Round 5 Time Attack).
I have 2 x air temp sensors (same type, ground and power source). 1 in the mouth of the MX5 (in front of the radiator) and 1 on top of the foam filter of the ITB's. Their position has remained unchanged. The reason for the big difference in the n number is that in later roads I split the data collecting to each session whereas for round 1 I kept all the data in one file. However, the data was collected at the track and hence there is very little data points between 5 and 60, there are numerous for 0 kmh as the car was parked in the pits with the engine running.
However I just realised that for round 5 I had a NACA duct in the OEM bonnet to give cool air to the ITB and this could explain why the OEM is showing cooler than the GV. I will have to find when I put the Duct in and look at the data just before that.
What it does show is that below 45 the GV works better than the OEM with NACA duct, however once speed increases above 70 the OEM/NACA duct runs cooler.
I will repost with the 3 lots of data, silly me did not save the working files...
Temp Diff by
Eipeip, on Flickr