Hondata

For a 5 Bar MAP sensor use a scalar of 1250 and offset of -625

This works for the AEM and Motec 5 bar MAP sensors (0.5V = zero absolute pressure, 4.5V = 5 bar absolute pressure).

Would it be possible for you to provide the same info for the Motorola 2.5 bar, based on this graph from their data sheet (bottom of page 3 on here: http://rocky.digikey.com/WebLib/Motorol ... SERIES.pdf )? I used 521.6 for a scalar, but have no idea what to use for an offset (if I even need one).

Thanks!! we just made 707whp 534tq but the map scalar was off quite a bit.. this should fix that quickly!! I think I used 1025 and -450, atmosphere was correct but boost was off quite a bit. We'll be going back for more power!!!

Motorola 2.5 bar:
Scalar 500
Offset 100

Is the MOTEC 3 BAR MAP's Part number M 16-0749 (page 38 of the MOTEC catalog)?

http://www.motec.com/catalog.htm

Hondata wrote:Motorola 2.5 bar:
Scalar 500
Offset 100

Thank you very much.

90ludetsi wrote:Is the MOTEC 3 BAR MAP's Part number M 16-0749 (page 38 of the MOTEC catalog)?

Yes.

Can you post the scaler and offset for the AEM 3.5 Bar map sensor also. Thanks, Paul

Here is how to calculate the scalar and offset.

1. Find the minimum and maximum voltage and absolute pressures.
2. Convert the pressures to mbar.
3. Subtract the minimum and maximum voltages to find the range, then do the same for the pressures.
4. Divide the pressure range by the voltage range to calculate the scalar.
5. Multiply the minimum voltage by the scalar to calculate the offset. Note that a positive voltage gives a negative offset.

So:

1. For the AEM 3.5 bar data sheet:
0.5V @ 0 kPa (absolute)
4.5V @ 345 kPa (absolute)

2. 345 kPa = 3450 mbar.

3. Voltage range = 4.0V, pressure range = 3450 mbar.

4. 3450 / 4.0 = 862.5 = scalar

5. 862.5 x 0.5 x -1 = -431.25 = offset

Plug in the minimum and maximum voltages to check your work:
0.5V x 862.5 - 431.25 = 0 mbar @ 0.5v
4.5V x 862.5 - 431.25 = 3450 mbar @ 0.5v

If you have trouble then draw a graph and exterpolate the lines until they cross the pressure axis.

Thank You very much! Paul

Thanks for the lesson. I appreciate it.

Thanks for the lesson. I appreciate it.

now i have to buy my map for my s300 and i think i seen it on the hondata website that the 3bar map goes up to 29 psi but accel have a 3 bar map that goes up to 44psi and i want to know what is the true psi of the 3bar map. also i wanted to know if i could use the aem map. would it make sence just to buy a five bar even if i don't boost crazy hi. just to have it for when i do AEM rates there's a 75 psi for there 5bar map

You must remember that 1 bar is used for reading vaccum. The stock sensor is a 2 Bar sensor.