my load level goes off the map with just below 21 psi ( with my mods, I flow more air).
I think load is calculated based on your MAF reading plus other info from sensors. Well, manly MAF(I tried with SAFC to reduce the MAF reading and it lowered the load on those areas I set to low).
I am now trying to get the same effect using the ECU Flash. SAFC was RPM based. But looking at the ECU Flash, it looks like it is not based on RPM or is it?
I wonder anyone knows the values assinged for maf scaling? is that Hz (192 ~16384)?

 

How do you know you've gone off the map? There is no way of tracing at which point we are running.

 

Well according to the initial post, the map reads to 23psi which is at 260%, So 240 is some where around 20psi, I hope. Man dam this is getting confusing need to change the load values to mbar or psi. I thought the ecuflash could not map over 23 psi just yet.

 

I can't belive you can't even trace the map. It is so easy! I will let you figure out your own.

Mchuang:
ECU doesn't know abut the PSI after 1 bar. it relies mostly on the MAF reading after that.

 

That cant be true so the ecu can only see vacuum? So how do you trace where you are boosting like how do I know where 20psi is. Also if that is true then how did the guy who wrote the how to know where 14.7psi is and also 23psi? Man I am dam confused now. We may need a whole new thread on load only lol

 

Since when is 1bar vacuum?

 

it depends if you are talking about absolute or relative pressure

 

Well, what does the ECU go by?

 

because the load is a calculated parameter i can't say for certain.

but in ECU tuning world
0-1 bar = vacuum - 0 vacuum (1 atmosphere)
1-2 bars = 0 vacuum - 14.7~ psi (1 atmosphere + 1 atmosphere of boost)
2-3 bars = 14.7~ psi - 31~ psi (1 atmosphere + 2 atmospheres of boost)

I think a good way of correlating what the load indicates in terms of boost is by going off the stock boost cut parameter. I know my stock ecu rom starts having a fit when it sees 1.5-1.6 as indicated by crappy stock gauge in the higher gears.

the boost cut parameter stock is set to "245" in the 3500-4000 range where i hit boost cut

 

Then that points more to 1bar being 14.7psi not 0psi in the ECU's eye.

 

because in a 3bar mapsensor for example 1 bar must cover the vacuum to get it back to 0psi then you have 2bar(each 14.7psi) left for boost that is why you see a 3bar max out at around 28-29 psi.

 

I think my original picture is a good approximation of how the load breaks down. my real world testing on the dyno falls in line with that chart.

I think using bars as the scale would be confusing because you would need to specify whether you were talking about absolute or relative pressure.

Standalone Ecus based on the metric system are referenced in KPA to avoid this confusion.

 

My question then is does the load values ever change or 200% stays at 14.7psi and 260% stays at 23.5psi until the map is rescaled or a new definition is put in?

 

IMHO, if im understanding your question correctly, it does change ever so slightly.

This is because boost is an indirect measure of airflow. With the MAF you are directly measuring airflow.

Hence why you can hit 1.5-1.6 of boost in 2nd or 3rd gear and not hit boost cut, but you hit 1.5-16 in 4th, 5th or 6th and you do hit boost cut. Where you hit boost cut is also dependant on temp.

 

1 bar is the map the map sensor we have on intake manifold. it doesn't read any higher. And using ECU Flash, we have no control over MAP sensor so we should just ignore that MAP.

MAF reading is not the direct measure of PSI. My car flows much more air than stock at the same PSI. Therefore, it gives more load value and more power at the same psi. MAF value will max out where you make the most horse power( when it flows the most air)