EFIDynoTuning Forum

I'm about to ask a question(s) that I should know the answer to but I just can't find the answer in my tuning log notes.

I'd like to prepare an alternative tune that uses different (Continental) injector data for my Deka V 80 lb/hr 'shorty' injectors. I have them installed and running using the Ford Racing M-9593-LU80 (Deka IV) injector data that's provided on this site but I think the difference between what I'm using and what Continental provides may end up working better.

The Ford Racing data lists injector parameters (slope, breakpoint, offset) at base fuel pressure of 39.15 psi and then provides compensation values that are intended to be multiplied against those base parameters to match the actual FP you're using. My base FP is 55psi, so the calculation looks something like this:
base ALOSL (101.459) x 55 psi compensation factor (1.2271) = adjusted ALOSL (124.5)
base AHISL (75.157) x 55 psi compensation factor (1.1883) = adjusted AHISL (89.309)
base breakpoint (0.00002421) x 55 psi compensation factor (1.121) = adjusted breakpoint (0.00002713941)
base voltage offset table values x 55 psi compensation factor (1.1848) = adjusted voltage offset table

Can I use these same multipliers (55 psi 'compensation factors' in bold above) with the Continental base parameters? To further confuse the issue for me, Continental base injector parameters are provided at 43.5 psi FP, unlike the Ford Racing data which uses 39.15 psi FP.

Can anyone help me sort through this?

Thanks,

Sean

no

OK.

How do I calculate/adjust the base parameters (low & high slope, breakpoint, offset) based on increasing my fuel pressure from 43.5psi to 55 psi?

Sean

you use the data provided otherwise dial it in

I can calculate slope and breakpoint adjustments for FP increase but am not sure if its necessary to add any latency to the offset table to account for the actual FP (55 psi) vs supplied offset values at 43.5 psi. Is there a rule of thumb for adjusting offset based on actual FP or do I simply need to use the supplied offset values and adjust as required?

Sean

no the offset will vary by pressure some coils take longer to open (most) some open faster

I dont understand why your not just using the information they give you?

I guess I'm confused by the Ford injector data including compensation multipliers for FP other than the pressure they offer slope & breakpoint @.

Continental simply has a single voltage/msec offset table, no modifier for different FP's. I can plug it in, but I'm trying to wrap my head around why some data (Ford Racing) is offered with alternative FP modifiers and some (Continental) isn't. I wanted to make sure I wasn't missing another piece of the puzzle.

Sean

All data had to be given for a specific pressure otherwise its useless