John Millican

iTrader: (1)

OK, it seems I got conflicting instructions to tweak the VE tables.

Trax says to set the injector constant once and leave it alone, now tune the VE tables.

Glenn says use the injector constant as a course adjuctment and tweak the VE tables for fine adjustments.

Thing is I have 24# injectors and my constant is up to 27# to get good BLM's. Should I change the constant to match the injectors or what?

If I mis-understood Trax or Glenn I am sorry, just learning some more.

drive it

iTrader: (1)

The idea is to use the inj. constant to get the Majority of the blms at or close to 128. Then in the (hopefully) few areas that are still off, then use the ve tables to "fine tune".

Grim Reaper

Actually, once you find an Injector Constant that get's you close to 128/128 for most of the VE table, you should never have to go back to the Injector Constant and only have to work on the VE Tables for "fine tuning".

What I don't advocate is using the Injector's "rated flow" as the Injector Constant and just tuning the VE Table (except if it happens to be fairly close to 128/128). The reason is because once you have set your fuel pressure to what you want to run (and most of us increase to fuel pressure to the 46-48 psi range to get the better atomization), I seldom find the "rated flow" is correct.

FYI, SVO 24# injectors are rated at 38 psi. If you increase the fuel pressure to 48 psi, it now has the equivalent flow of 27# injectors.

John Millican

iTrader: (1)

That's news to me. I mean I heard it before but I believe it now that I see it on my car. I have the AFPR set to 48psi and my constant is about 27.1# to run 128 blm. Good call Glenn. thanks.

V8Astro Captain

iTrader: (1)

If I calculate my BPW constant, by the books it should be 135. I was rich all over so I set it to 133. Now I'm tuning the VE tables using 133 as my BPW.

TRAXION

Basically, when you are focusing on the VE tables and tweaking the VE tables you want to leave the Injector constant alone. I am not saying that you should not make some coarse adjustments using the injector constant BEFORE you tweak the VE tables .... I am just saying that once you start tweaking the VE tables that you want to leave all other variables in the fuel system alone (i.e. don't change the fuel pressure, don't swap injectors, don't change the injector constant, etc).

Tim

John Millican

iTrader: (1)

Thanks for the clarification Trax.