TP & MAP load control

[number 7]

My 2 Group system installed on a N/A modified RV8 in a TVR 20 years ago is throttle controlled load, but with a MAP sensor fitted. I never got a proper explanation from the in installer why a MAP sensor was fitted. I have just replaced the original sensor (1 bar GM type), and this got me thinking: the 2 group manual says that in such a set-up, the sensor "optionally measures barometric pressure if TP controlled". Does this imply that in this case the sensor should not be connected to the manifold (i.e. only connected to atmosphere)? The little understand about this suggests that the MAP sensor can only read barometric pressure prior to engine start if connected to the manifold. Any thoughts please?

[SprinterTRD]

A little rusty on 2G ECU's!

When MAP based load is used, the ECU samples for atmospheric pressure when the ECU powers up and engine is not rotating.

When using TP as load, you don't need the map sensor connected to the manifold ( unless you have a supercharger ) however I probably wouldn't change this as it will most likely change your tune.