I did a similar mod today with stock air box and filter (plan to change to K&N drop in filter).
I didn't do any testing beforehand like I should have, but after, here were my results using TORQUE for android via an ODB bluetooth module.
With outside temp at 95 (per MFT display):
At park / idle: ambient air at 102 and intake air at 112~117
Cruising at 30: ambient air at 102 and intake air at 107
Cruising at 50: ambient air at 102 and intake air at 102
That's all the testing I've done so far...