Primary / Sec injector opening time scale modification

[Alecvey8]

Hi all,
I’m currently trying to dial new ID1750 XDS injectors.
I’m currently struggling to dial the « dead time » or injector opening time table.
I want to modify the scale / values related to the relFp1 axis to make it match with the data provided by ID, in order to populate the adequate corrections.
Converting the Psid values used by ID in mbar is easy, but the scaling won’y fit properly.
Any ideas / help would be appreciated
Cheers.

https://injectordynamics.com/id-1750-xds/

[stevieturbo]

you would need to pick your baseline pressure in terms of flow, then everything else is relative to that.

eg, if you choose base 60psi, that's your 1.00 in the relFP table
edit, I was arse about face...

43psi 2044/1728 = 1.183 is your multiplier for the lowest pressure offered
100psi 2044/2645 = 0.773 is your multiplier for their highest.

That should try and maintain fuel flow consistency if pressure varies.

It may or may not be linear in between. Probably not. But plot a graph if you need to or for slightly different values if you think they are not close enough.

Although I'd like more values for lower than 43psi, especially if you intend to run 43psi as a base, just in case pressure did drop a bit so it can compensate a bit for you prior to any relFP1 trips becoming active for safety.

Or you can change the relFP breakpoints in the Breakpoints and thresholds.

[Alecvey8]

Thanks Stevie for your feedback, but I think I was not enough clear.

I'm talking about the table under run mode fueling/corrections/Primary injector opening time.
This table provides an offset in millisecond which depends on Vbat and RelFp1 (according to the table).

I was trying to modify RelFp1 breakpoints as you mention (in order to make them matching with the data provided by ID, converting PSI in mBar), but under "breakpoint and threshold", it appears that modifying the "relative fuel pressure breakpoints" doesn't affect the table I mention above.

However, what you said brings up another question in my mind :
the "Primary injector opening time" table second axis is labelled "RelFp1" but now it's not clear for me what are we talking about ...
For me, since the scaling is in mBar and judging by the numbers displayed, I was thinking it is the realtive fuel pressure ("relative" by opposition to "absolute") in the fuel rail.
My fpr baseline is adjusted @ 43,5 PSI (pretty common), which should directly correspond to the 3000 mbar line.

[stevieturbo]

silly me.

the breakpoint adjustments for that table are literally above it, Injector opening time axis.

3000mbar on the table would be 43.5 psi, yes.


As a baseline, engine off, FP and relFP would be the same at normal "1 bar" atmospheric conditions, so filling in the table with their values would be correct.
After that actual FP is less concern, as the injector only sees relFP, which all being well should be fairly static

[Alecvey8]

Thanks a lot
I feel really silly too, I rushed in the « breakpoint » section whereas the answer was sitting just a line above