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killerbee
October 25th, 2009, 01:58 AM
If anyone has a foothold on this table, defined as:

"These multipliers are used by many tables in the ECM."

Could you please demonstrate how you derive a "multiplier" and an example of how you use it in one of the "tables". I have a token bet with a friend that nobody can do this. :) Prove me wrong.

bballer182
October 25th, 2009, 03:01 AM
Oh yeah thats a cool one.

So lets say you are at 14.5 psi (sea level) that table (B0202)will set the ECM in to "LOW" altitude tables. Then you are climbing a hill and at some point your BARO sensor reads 13.5 psi the ECM will use a weighted average of the MED and LOW altitude tables. 20% MED and 80% LOW. So you continue up this hill so that the BARO sensor reads 12.0 psi the ECM will only use only the MED tables. And so on....

View the numbers as percentages; it makes thing a little easier to understand.


sorry to make you loose your bet.:doh2:

killerbee
October 25th, 2009, 03:39 AM
sorry to make you loose your bet.:doh2:

I want to lose, but I haven't yet.

(This table spins me in the wrong direction for one reason, labeling on the last column. How about labeling it "low", instead of "sea". (Ross) "Sea" does not appear on any of the ECM tables.)

So if I understand correctly, you will typically come up with as many as 2 "weight" factors from this table, that are then used to interpolate up to 2 target tables. So you did half my question, now an example of use.

Example: using LBZ stock at 12.2 psi baro, egr off, 20mm3, 2000rpm, ECT=68F, IAT=68F: What is Desired Boost (MAP) for this set of parameters?

GMPX
October 25th, 2009, 09:43 AM
(This table spins me in the wrong direction for one reason, labeling on the last column. How about labeling it "low", instead of "sea". (Ross) "Sea" does not appear on any of the ECM tables.)It's funny you say that, I wish I could find the Email from someone who's opinion I respect who suggested that we call the 'Low' Baro 'Sea' as it gives people a real reference, someone might not actually be able to picture in their mind Low or High and what that means. Maybe I'll just call them Los Angeles, Mid and Colorado :)
But you are correct, the same term should be used throughout.

killerbee
October 25th, 2009, 10:15 AM
Hopefully it wasn't me. OMG, that is hysterical.

killerbee
October 25th, 2009, 11:35 AM
Just a suggestion for a description then. This would at least take some of the mystery out of this. "multipliers" is not working for me, but that's just me.

"This table defines the weighted value(s) that you will use to establish various operating parameters found throughout.

For example, at 4200 ft elevation, the baro PSI is 12.4 psi. If the values found on this table are high (0.0), medium (0.80) and low (0.20), then the actual parameter will be an interpolation of the med and low target tables, adjusted with the respective weighting".

If someone can improve that to make it easier or more intuitive to understand, take a wack and revise it.

bballer182
October 25th, 2009, 03:58 PM
I want to lose, but I haven't yet.

(This table spins me in the wrong direction for one reason, labeling on the last column. How about labeling it "low", instead of "sea". (Ross) "Sea" does not appear on any of the ECM tables.)

So if I understand correctly, you will typically come up with as many as 2 "weight" factors from this table, that are then used to interpolate up to 2 target tables. So you did half my question, now an example of use.

Example: using LBZ stock at 12.2 psi baro, egr off, 20mm3, 2000rpm, ECT=68F, IAT=68F: What is Desired Boost (MAP) for this set of parameters?


Ok, I decided to edit your story problem a bit. instead of 12.2 psi BARO i used 12.4, which, is a row on the table B0202. I didn't feel like interpolating the 12.2 psi. so the answer to the story problem are stated is 19.45 PSI requested boost (MAP). OS 6128

bballer182
October 25th, 2009, 03:59 PM
It's funny you say that, I wish I could find the Email from someone who's opinion I respect who suggested that we call the 'Low' Baro 'Sea' as it gives people a real reference, someone might not actually be able to picture in their mind Low or High and what that means. Maybe I'll just call them Los Angeles, Mid and Colorado :)
But you are correct, the same term should be used throughout.

I agree i never noticed it was labled (sea) i just always assumed it was labeled LOW.

killerbee
October 26th, 2009, 02:16 AM
19.45 PSI requested boost (MAP). OS 6128

with IAT and ECT corrections?

OK, it was a good exercise, thanks.

bballer182
October 26th, 2009, 11:32 AM
with IAT and ECT corrections?

OK, it was a good exercise, thanks.

Yes with all of the corrections. However, at 68*F IAT left the boost request unmodified, so it wasn't a factor.