What it does and how far it reads
The internal MAP sensor turns manifold pressure into a signal the ECU uses for load. On older Elite firmware (v2.xx, tuned in ESP) it's a 3 bar sensor, good for up to 200 kPa of boost, which is about 29 psi. From v3.xx firmware, tuned in NSP, the supported range was raised to 4 bar.
If you plan to run more boost than that, or want the sensor mounted closer to the manifold, use an external sensor such as the 5 bar TI MAP sensor. See our external MAP sensor article for wiring.
Plumbing the hose
- Keep the vacuum hose as short as you practically can. Long hoses slow the signal.
- Secure both ends with hose clamps or zip ties so it can't pop off under boost.
- Take the signal from a point above the injectors. If the hose tees in lower down, fuel can collect in it, run down to the ECU and ruin the reading or the sensor.
Our tip
Route the hose so it runs downhill from the ECU to the manifold. Any moisture or fuel then drains back to the engine instead of toward the ECU.
