Air-Meter

[Alpineandy]

Hi,
Where on an EFi engine is the Air-Meter?
Is it the same on the R25, Espace etc?
Cheers

Air meter as in Map sensor, or air temp sensor.?

If its the air temp, its in the side of the throttle body, if its the map sensor, then just follow all the vacuum feeds from the inlet manifold till you see a little flat black box with a 3 pin plug in it and the end of the pipe..

[Alpineandy]

Air meter as in Map sensor, or air temp sensor.?
map sensor, then just follow all the vacuum feeds from the inlet manifold till you see a little flat black box with a 3 pin plug in it and the end of the pipe..

Yes for the Map. So it's a flap type. Thanks.
If you change the throttle for a different (larger) one, I guess the standard one can't be used (or can it?), so what should it be upgraded with?

If you change the throttle body so that the engine sucks more air (if it demands it) then its not the map sensor that needs changing, its the map in the ecu, as the mapsensor will still be seeing the same pressure, but you have increased flow through the engine , hence more air, and thus more fuel needed.

You could get round this by running more fuel pressure, but this will affect all overall fueling too.

[Alpineandy]

So the air 'sensor' will physically fit a larger throttle.
Thanks

So the air 'sensor' will physically fit a larger throttle.
Thanks

Yes, the feed to the sensor comes off the inlet manifold, not the body.

The PRV doesn't use an air flow meter, you can fit as large a throttle as you like. japanese engines tend to have air flow meters and there comes a point where a larger throttle makes no difference because the air flow meter is the biggest restriction in the intake. A common "upgrade" when replacing the ECU on a skyline, for example, is to bin the air flow sensor and convert it to speed density type, like the PRV, which uses a MAP sensor and air temp sensor to meter the air.

The PRV doesn't use an air flow meter, you can fit as large a throttle as you like. japanese engines tend to have air flow meters and there comes a point where a larger throttle makes no difference because the air flow meter is the biggest restriction in the intake. A common "upgrade" when replacing the ECU on a skyline, for example, is to bin the air flow sensor and convert it to speed density type, like the PRV, which uses a MAP sensor and air temp sensor to meter the air.

You can't use as large a throttle as you like as it will run lean.

The PRV doesn't use an air flow meter, you can fit as large a throttle as you like. japanese engines tend to have air flow meters and there comes a point where a larger throttle makes no difference because the air flow meter is the biggest restriction in the intake. A common "upgrade" when replacing the ECU on a skyline, for example, is to bin the air flow sensor and convert it to speed density type, like the PRV, which uses a MAP sensor and air temp sensor to meter the air.

You can't use as large a throttle as you like as it will run lean.

Mmmmmmmmm what happens when you have a large tube mmmm air speed drops = lack of torque at bottom end, you cant just go as big as you like without effecting throttle response thru the range so bigger is not always better! thats provided you get air fuel right!!

Si21