PW calculation - Baro impact / ITB

EMU PRO
1

Hello,

Is there a rough overview about the PW calculation of the EMU Pro?

I wonder if it does include a Baro correction by default ?

I’d expect the PW equation is like
PW = DeadTime + Inj_Constant x VE (RPM/Eff-Load) x MAP x AirDensity x Corrections

Corrections: Afterstart, Warmup, Ethanol, Custom, Short/Long-Trim, Transient, …
And AirDensity only sensor impact by IAT / MAP, but no Baro.
Right now I got no PRO here for testing.

Background: Motorcycle w/ ITB.
At low TPS I got a good MAP signal.
Above 10% TPS it gets already close to Baro
However at high rpm full load MAP gets unstable.

That’s why I’m using multiply-MAP only at low TPS and then blend over to multiply-Baro at high TPS. (with my current ECU).
However this strategy seems not available with EMU pro? As MAP is always included.
Eff load axis is TPS.

I mean I could use a the Baro at the MAP input, would work good at full load, but disadvantage at low load. Similar behaviour if I add a dampener to the MAP-Line.

2

Hi,
There is currently no option to blend MAP and BARO.

But EMU PRO can sample MAP at a specific crank angle, which should solve all the issues you mentioned.

3

thanks for you reply.

Okay I’ll see if I can set the Sampling window, in a way, that the resulting MAP signal will be more stable at full load load 10.000-14.000rpm. So far away from the open intake valve.

It looks like I can set the starting angle of the MAP sampling window in the PRO software.
But how long is the sampling window duration °CA ?

And do you have actual plans to implement MAP/Baro blend for a future software release?

4

It’s not a window. It’s a single sampling point.

Blending different fuel models is on our to-do list, but no timeline for now.

5

The OEM’s solve this issue with two different VE tables:

  1. MAP vs RPM (used when TPS < 4%)
  2. TPS vs RPM (used when TPS>4%)

In the EMU black you can mimic this behavior, probably works in PRO as well.

  1. VE table1 = TPS vs RPM but all bins are filled in as 100%. Add a Custom correction table1 RPM vs MAP that scales the 100% VE. Make a rule that enables the custom correction table if TPS < 4%
  2. VE table2 =TPS vs RPM, just an alpha-N table. Add custom correction table 2, BARO vs BARO that scales the VE2 table. Make rule that enables VE2 table + custom table 2 if TPS>=4%

Work quite all right on my bike (Triumph). And gives me Speed density at low load, Alpha N at partial load and Alpha N with Plenum pressure multiplication (Not MAP) during boost.

6

Hi ArvidW,
thanks for letting me know. Sounds like a good workaround for the Black.

But from my understanding, It would’t be possible with the PRO. Please correct me if I’m wrong.

  1. With the Black you can select between “Alpha-N” and “Alpha-N with multiply MAP”.
    For your workaround Alpha-N would be the right option (in order to get TPS as axis). With the PRO I don’t have this option. When selecting TPS as Eff-Load, MAP (-multiplication) will be still used for the PW calculation. Therefore I’d still have MAP impact for the 2nd VE table.
  2. In order to mimic your two custom currection tables with the PRO, I have have to create a 4D custom correction. (With the PRO there is only one custom correction table, but 4D is possible)
    But I can’t set seperate axis for the two z-values of my custom correction 4D map.
    So it doesn’t work to set BAROvsBaro for one correction map (z=0) and RPMvsMAP for the other (z=1)
7

@Chef_Koch to add to this, the MAP sampling does what you’re wanting. For example at power on the ECU can sample the baro based on the MAP value. This also allows it to sample during WOT where your MAP would equal Baro approximately. There are also other capabilities where the ECU can detect a compression stroke during cranking. The OEMs use this method to determine baro, adding a sensor for it will not add any additional performance.