I nave seen the future ....Its AEM

[TLicense]

Jake,

 

I think what Ali is talking about here is a method of mapping called "boost compensation", nothing hidden or difficult to do, in fact I think AEM actively promote it as the prefered way to map your car (the supra basemaps are done this way)

 

What you would do basically for this is map for one load (say 10 psi). You would then copy the same values for 10 psi all over the main fuel map, so you end up with a main fuel map that only has the values for 10psi on. There is then a modifier table that you can use to multiply those fuel values against load. The basics is that say for 6000 rpm, at 20psi you would need twice as much fuel as 10psi. So on the modifier graph you simply set it to 200% for 20psi. This means that you can build up a map v.quickly compared to the old way of working out what each cell (fuel value) would be at each rpm and load site.

 

The problem I have is that because I have a FSE rising rate fuel regulator, it means that my boost compensation graph isn't a straight line, which makes is a bit more of a pain to map. Hence why I'm going to be flogging it for an aeromotive 1:1 regulator and fitting correct sized injectors.

 

Loads more detail on boost compensation can be found here on the aem forum

[Jake]

I see. Thanks Tony

[JohnA]

.....The basics is that say for 6000 rpm, at 20psi you would need twice as much fuel as 10psi.

 

Are you sure mate?

[carl0s]

Are you sure mate?

 

is it: at 1bar you need twice as much as at 0bar? ?

[JohnA]

yes.

 

The half of airflow at 20psi boost is slightly less than that at 3 psi boost. Airflow and fuel requirements go together (more or less) if you want to keep AFR the same.

 

Nit-picking really, shouldn't distract from the valid point made by TLicence.

[TLicense]

huh?

[JohnA]

Simple mistake to make mate, not to worry.

 

Airflow is proportional to absolute pressure you see, so 20psi is really 14.7 + 20 = 34.7

Now the half of that is 17.3, which in 'boost' terms is 17.3 - 14.7 = 2.6psi

[TLicense]

ahh yeah, but I never said PSIG did I?