Injector BPC Affect Cranking BPW

[Jayme]

yeah a lot of the B tables arent set to stock values. you really should go through them first up and set the values. I think most of it was a throwback from testing to make sure that flicking to B maps was working.

[vlad01]

so what is the correct table? A?

I am running on map B atm coz A is corrupt, seem to start fine even with half the values of map A

[Jayme]

no, confusion is present here LOL.

map A/B in the xdf is switched by grounding pin B9. map a/b on the nvram changes the ecu to use either upper or lower half of the nvram chip...

[vlad01]

wha??

so does that mean 4 potential tunes?

[Jayme]

sort of... not every item has an A/B split in the xdf... for example VE is shared across both A and B (As you are supposed to tune this to your engine airflow) , but you can change the target AFR in A/B separately so you can have a tune to suit a different fuel.

[vlad01]

ah right, forgot about that.

So that means I use MAP A in the tune, but need to upload the bin twice once when on NVRAM set to A and once when set to B so I have the same copy in both locations?

Anyway I copied tables from A to B just to make it the same for the heck of it. Going by what you said, the correct values are on MAP A for the V6?

[Jayme]

yep, thats it. upload once with pin on, once with pin off or if writing the nvram in an eprom burner just stack it 4 times then burn to make both memory locations the same.

[Holden202T]

Map a/b switch inside the tune is primarily good for changing fuels, 91 vs 98 octane timing maps or e85 and petrol etc ... When vl400 first added it to the early 12p it did its job, then I started running petrol / methanol tunes in the Gemini and we soon found out a lot more tables needed to be changed to make map switching really work properly for different fuels, the end result is a lot more confusing when you first look at it, but the ability to control this sort of setup is greatly improved due to the extras!!

For example I can now run a 2 step rev limiter, when I press a button on the gear stick, it switches maps in my ignition module to set spark cut at 3000rpm, and at the same time it switches maps in the ECM to reduce timing by 10 degrees and also adds a lot more fuel, so I can have the motor up on the converter, staging on the line with full throttle, and when I let the button off I launch with full throttle and everything back to normal in the tune, and the advantage of this is I can actually build boost on the line rather than after I leave!!

This is merely one example of its use!

[vlad01]

ah now I understand how you got the 2 stage launch.

[Holden202T]

yeah its not possible to do it without the ignition module to cut the spark!