Altitude compensation

[gunnerthesnowman]

Preview: Re: Altitude compensation

If you have your fuel table spanned off MGP then you get barometric correction all the time, OK THAT ANSWERS THAT

not just off boost. There is no distinction between on and off boost, it is just a different MAP pressure.

As the ECU is very configurable, there are many options for how the fuel calculation and mapping is configured. It is very hard to explain in general as it depends on how you configure the ECU as to how barometric correction is applied.

Here are some points to note:

- When the fuel equation is on Load = MAP, there is NO barometric correction applied by the fuel equation.

- Having your fuel table spanned off MGP is what gives you barometric correction as MGP is a function of barometric pressure.

- If MGP is used to span the fuel table and your engine is tuned properly then you get barometric correction everywhere.

Please ask specific questions about your exact application or give me examples to explain and I will try answer them.

So in short for almost all applications use:

Fuel equation Load=MAP

Fuel table Y axis = MGP--- AND IF RUNNING THE OPEN LOOP TABLE IF HAS TO BE SPANNED OFF MPG AS WELL

Ignition table Y axis = MAP OR YOU COULD SPANNED IT OF MPG FOR NO BAROMETRIC CORRECTION

You say to ask specific question which i did / have , that when Ray said he found out that he did not know that spanning the open loop table Y axis = MAP with the fuel equation load=MAP , fuel table Y axis= MGP --- that i would not have barometric correction

He said he found out that the Open loop Y axis has to be MGP------ OK that done

But he also said with this set up i would only have barometric correction on off boost ----- this did not make any cents to me ----that why i asked more specific question .

Which i hope you have finally answered ---Thank you

Ray also said to have the timeing Y axis table spanned MAP for no baro correction and MGP for Baro correction

Now you say

Map for baro correction and MGP for no baro correction

No wonder why i am getting confused

[gunnerthesnowman]

So to start over again to try and make this clear for me , to get barometric correction on my V-88 on my turbo charged sled i would set it up this way .

Fuel equation Load = MAP

Fuel table Y axis = MGP

Open loop Y axis =MGP

Ignition table Y axis = map ( for barometric correction ) OR MGP ( for no barometric correction )

Thank you .

[ashesman]

You should set it up as:

Fuel equation Load = MAP

Fuel table Y axis = MGP

Open loop Y axis =MGP

Ignition table Y axis = map

There is no application for barometric correction for ignition as spark advance is relative to cylinder pressure which is relative to charge pressure (MAP). This is the most common setup used by most tuners.

[gunnerthesnowman]

You should set it up as:

Fuel equation Load = MAP

Fuel table Y axis = MGP

Open loop Y axis =MGP

Ignition table Y axis = map

There is no application for barometric correction for ignition as spark advance is relative to cylinder pressure which is relative to charge pressure (MAP). This is the most common setup used by most tuners.

Thank you .