Just wondering how much downforce does the rear wing and the front end create at say 100mph.

 

Can't answere that exactly. Litreature from Honda claims that aero-package reduces lift by 30% and drag by 1%. This is obviously at fairly high speeds.

 

Ah....downforce....
My ATR has a rear spoiler as well. It is also equipped with some sort of sensor (probably a variable resistor) hooked up to one of the rear-suspension rods so that it can compensate for the front lights (krypton) with different loads in the trunk. This feature is standard on ATR's for the purposes of not blinding traffic when there is more weight in the trunk.
Now, I assume that the ITR has the same feature (?) but if so you could do the following:
1) Raise car to get access underneath and locate this 'sensor'.
2) Hook up two wires and route into the car.( these wires will be going to a controller (ECU?) for sure but I dunno which one/location...)
3) Hook up a VDC meter (any cheap one will do) and measure VDC at , let's say, 50kmh, 100kmh 150kmh and 200kmh. Record all voltages.
4) Now,whith engine running idle and standing still put various weights in the trunk that give the same VDC readings...Voila, ....downforce measured.

I was planning to do so myself some time ago but kinda lost interest.
Good luck~!

 

I read on another message board that the rear wing produces 300lbs at 90mph and the front end produces 190lbs. That seems a little unbelievable though.