mixture at WOT (wide open throttle) and slightly advances the ignition timing. The result is increased horsepower/torque if previous airflow-enhancing mods (intake, exhaust) have caused the engine to run lean. The benefit is greater in hot weather conditions.
Relocating the IAT sensor is easy. I kept the stock sensor in its original location. I bought another sensor from a junkyard Jeep 4.0 HO engine, drilled a hole in the airbox lid just big enough for the sensor to fit tightly, and screwed it in.
This is how it looks from inside the airbox (arrow).
I then extended the wiring to reach the relocated sensor. This gives me the ability to switch between the two sensors if I want. Voila. As easy as that.
Did this modification improve performance?
Definitely. Even after correcting my times for elevation, vehicle weight, barometric pressure, ambient temp. and humidity, acceleration at WOT from 30-50mph in 4th gear (26.6mph/1000rpm) improved from 7.7 to 7.5secs , 40-60mph from 8.0secs to 7.7secs, 50-70mph from 8.3secs to 8.0secs, 60-80mph from 8.8secs to 8.4secs, and 70-90 from 9.7secs to 9.2secs.
This translates into a gain in rear wheel torque of 4lbft at 1500rpm, 6lbft at 2000rpm, 7lbft at 2500rpm and 7lbft at 3000rpm.
Those are solid gains for such a cheap mod.
Was there any change in fuel consumption ?
No. Long term testing didnít show any tangible change in gas mileage. This indicates that part-throttle fuelling is not affected by this modification.
Probably the best bang-per-buck performance mod for this engine, and thereís no downside. Highly recommended.