3 bar maf upgrade

[ssmokeyy]

Can I order a 3 bar and install it in the place of the 2 bar with out any other problem's or will i need to do something for the ecu to understand it?

[rip]

You mean a MAP (Manifold Absolute Pressure) sensor, not a MAF (Mass Air Flow) sensor?

Yes, balance this change by fitting bigger injectors.

The output of one of these is 2/3 the output of a 2 bar sensor. so it gives the same output at capacity.
Therefore at any given pressure, it will trick the ECU into showing 2/3 the real value & therefore the ECU will provide 2/3 the fuel.

So why trick your ECU?

The ECU controls your injectors by varying their pulse width. If you change your injectors for ones with 1.5x the capacity of the originals, they will provide 1.5x the fuel but the ECU will be unaware of this.

The ECU will then provide 1.5x as much as it believes, but it believes it only has to provide 2/3 of the true value.
The fuel cut-off will still activate at what the ECU measures the overboost value to be, but because the ECU is being fooled, this will really be 1.5x what it is reading.

[ssmokeyy]

So i have a set of dsm 450 injectors. Are these to big? Will they work on this car?

[ccb056]

stock injectors are 320cc

[tigerdog]

Hi Smokeyy, please use the search function and find the (many) other threads dealing with this subject. Most who have made this change have gone to RC Engineering 550cc injectors; these are a tad bit oversided and result in nominally 14% rich running under full load. Since most who do this are also increasing boost beyond 1 BAR, it provides a measure of safety. The ECU only compensates at idle and under closed-loop, light load running.

450cc injectors would be undersize (320 * 3 / 2 = 480) and the car would tend to run lean. I would not personally feel comfortable with this setup unless something else is done (custom chip, custom ECU) to compensate.