power fc, from 550cc to 740cc injectors, new map?

[drftsx]

I have a power fc with a tune for 550cc injectors. With my 2871r, i am pretty much maxing out the 550ccc with 1.1 bar of boost. Will be upgrading to either 740s or 850s. Do i need a completely new map, or do i just go in and change my injector values and lag time?

Ignition timing map should be the same right? What about the other map??

Thanks

[Shift_Kouki]

Should just be injector values and lag time... Unless something is being strange.

[sommmatt]

You're gonna have to lean it out... tune by AFRs. It's just fuel you have to play with so it should be no issue.

[kouki munster]

You will just need to decrease the injection time,(not sure how the power fc is set up compaired to a haltech) and you should be able to find a formula online to figure out the percentage it needs to be dropped for the change in injector size. But the afr's should be closely monitored while you are making any changes to the fuel map.

Edit: also I recomend a set of at least 850's, as I'm running a set of 740's with a 20g and my injector duty cycles are in the mid to high 80% range in high rpms at 17-19 psi with 11 afr's. When ever I get a wastegate actuator with a stiff enough spring that can actualy hold 23 psi to 8k I'm sure that the injector duty cycles will be over 90%. (anyone want to buy me a top feed fuel rail ro fit a s14 sr and some 1000cc injectors)
Modified by kouki munster at 1:43 AM 12/8/2009

[drftsx]

So the current fuel map is made specifically for the 550s? I know how to change the injector size and lag time and such, its just the fuel map that i am not sure on.

What i am getting at to not confuse people (hopefully i will make sense),

Is the fuel map independent of the injector size, as long as you change the injector values?