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thoughts on this map


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evening all, ive attached my map from my rb26 which was done by a very reputable tuner and was really just interested to see what the pro's here make of it.

one of the things that has concerned/confused me is how the 4d fuel maps are setup. So the way I see it is this, the fuel table 1 uses tps as its load input, and this map has been used to control the majority of the fueling, where as the fuel table 2 uses MAP as its load input, this table is adding fuel from 1.2bar to 2bar of boost. Now, what confuses me is this, from 0 - 1.2bar the fuel is controlled by fuel table 1, so if I am at WOT / 100% tps and moving across the bottom column of the fuel table 1, the ecu will be delivering the same amount of fuel regardless of boost pressure, as its using the TPS as the load input, so I could be at 0.2bar or 1.0bar and the ecu will be delivering the same amount of fuel..? Am I missing something here?


interested to hear your views on this. cheers dan



new engine 2017.pcl

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Your map looks like standard issue "GTR strategy" to me.  The factor you're missing is the fuel equation source is set to MAP so the fuel pulsewidth is already automatically adjusted in the background (proportionally) with MAP.  The AFR/Lambda target table then looks after the fact that you want a richer mixture at higher MAP.  The 4D table is sometimes not needed but in your case it looks like it is being used as a final tweak at high boost pressure, this is usually because at higher pressures the turbo efficiency is dropping off and the normal linear compensations dont apply enough correction.  


Edited by Adamw
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I don't quite understand where it is controlling the fueling from at 100%tps under 1.2bar if it's not from fuel table 1? 

In simplistic terms it goes something like: value in fuel table/100 (the 100% TP cell in this case) multiplied by (MAP/100), multiplied by (1/lambda target table), multiplied by fuel master.  

So a couple of quick examples:

Fuel table number in 100% cell = 50, 80KPa MAP, 1.0 lambda target, 10ms master = 0.5 x 0.8 x 1 x 10 = fuel pulsewidth = 4ms

Now if we come to a hill or increase boost - same fuel table cell:  Fuel table number in 100% cell = 50, 120KPa MAP, 0.8 lambda target, 10ms master = 0.5 x 1.2 x 1.25 x 10 = fuel pulsewidth = 7.5ms

So can you now see that even though we are on the same main fuel table number which only references TP, the fuel pulsewidth is still increased with MAP?


Edited by Adamw
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