I saw a test in a Truckin' mag on a unit made by Python Injection. Works similar to a chip but ONLY works at part throttle. Why would a company do this? Out of curiosity I checked out their web site. They say the unit will work in conjuction with chips.

They actually did get some good performance improvements. They used a Clayton dyno and the part throttle "load" tests. Passing test on a Suburban showed great improvements, I guess they limited the amount of gas pedal because they advertise the unit does NOTHING at WOT.

I can't seem to find the logic. Wouldn't this require CARB approval to tune at part throttle? If so, why not improve WOT?