2 potentiometer working as 1
Just to let you know that this has been solved. Thanks to all for your help. Here is what i have done.


soldered the two neutral pots wiper to each other
soldered wiper 1 to wiper 3 on the other pots and 3 to 1 obviously
solder the three wire coming from the transmitter himself to throttle pots ( any should do the trick ) following wire order....
set each pots to neutral when pedal is in stock position
adjust throttle trim accordingly


And here we go it works flawlessly! Simple enough.

Now i want to say that the pots used all of the three wipers on my transmitter,  but originaly in the steering wheel pedals they were using only two. My confusion started here. 

Thanks again everyone you are all awesome !