MAP adjustments

Hello All,

I don't quite understand how the MAP calibration tables work. I understand that it effects the MAP sensor and how it reads the Air destiny. What I don't quite get yet is how to calibrate this table.

The table I have is rpm/psia with the load % as the adjustment point. Lets say your at 5,000 Rpm's at 250 load % and the table says 170, does this mean the ECU will take fuel out, try and lower boost? What does this table do?

Tuner software I am using is ECUflash EVO X

Thanks,

Justin Takeuchi

The MAP calibration is by definition a 2D table, it doesn't have a 3rd axis and it's definitely not related to the rpm.

It just tell to the ECU the pressure (in kPa or Psi) VS the voltage (or binary value of the said voltage)

The load, if expressed as a %, is a ratio of the intake pressure VS the atmospheric pressure.

250% would be ~36.25Psia (~250kPa) or ~21.5psi (~1.5bar) of boost.

So, you should add a screenshot, it would be way easier to help you that way.

The table you're talking about sounds more like a Fuel table in VE (volumetric efficiency) who is also a %.

Here is a screen shot. Thank you for your help on this.

That's a fuel table.

There is 2 tables on your screenshot but they are the same, just with a different unit for the map.

(One in kPa for most of the world and one in Psi gage for the USA I guess, but it's way too confusing for me)

X axis (horizontal) is the map value (load), Y axis (vertical) is the RPM and the Z axis the volumetric efficiency in (%).

In a perfect world, to get 1 lambda (14.7:1 AFR for pump gas) you should have 100% VE at 100kPa 200% VE at 200kPa and so on.

But, most engine have a VE around 80/85%.

For your car now.

For example at 102.83kPa and 5000rpm in theory you should have 102.83% but you have 92.2%.

if your engine was perfect that would be 102.83/92.2=1.114 or 16.34 AFR (lean)

Now if your engine have a real volumetric efficiency of said 80% in that zone, that give you a lambda of 0.87 or 12.75 AFR (rich)

Thanks for the reply. It would be nice to know.

1. Why I would need to adjust this table?

2. What this table will effect?

3. If the 92.2 at 5000rpms was to be changed to 100 what would happen

WOW.

Justnii, invest in yourself: https://www.hpacademy.com/hpa-starter-package/

Hi Dynodom,

Thanks for the advice. I have invested in the whole course package!

Attached is the High Octane Fuel map I adjust to get the cars running the correct AFR's. What I don't know is what the map I posted before this does. Does it work with the high octane fuel map? That's what I am trying to understand.

Add to question - dose this table apply all the time or just in closed or open loop?

Thanks,

JT

That looks like AFR target map.