J-spec MAP sensor

[adi]

Does anyone know what the max readable pressure is for the j-spec MAP sensor? Am i right in thinking around 1.3 bar? does it still work in the normal 5v way?

 

Basically i need to change my 1 bar MAP at some point, but a 2 bar will give me too much voltage loss to the ECU, so im trying to find an inbetween.

[Paul Whiffin]

18psi off the top of my head.

[Ian C]

Agreed. About 1.25bar.

 

-Ian

[adi]

Cheers guys, do you know if the voltage at 1.25 bar is 5v? And whether or not it is a linear relationship between pressure and voltage?

 

Ps if i sound like i know what im on about.. its a mistake.. i dont.

[THOR Racing]

Yes the MAP sensor is a linear device around it's normal working pressure range. I think it starts to go non-linear very close to it's max pressure.

 

The MAP sensor is driven by a 5V regulated power source, the max possible output is therefore 5V but you'll find that you'll probably only get about 4.96V (ish) max.

 

This equates to about 18.5psi

 

To replace it with a 2 bar MAP sensor you'll have to scale the new MAP signal such that the idle point, max pressure and atmospheric pressure measurements are the same.

 

So you'll need to measure it properly on the old MAP sensor and then properly measure your new one (or obtain a graph from the manufacturers)

 

Pete

[adi]

Cheers Pete.

 

Im actually trying to replace my 1bar map with something able to measure my increased boost of around 18-19 psi, hence the 2JZ map may be perfect. This coupled with an SAFC and bigger injectors should workout nicely.

 

 

Cheers

adi