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View Full Version : Racetronix 79 lb/hr high impedance injectors



bobbycollier
March 24th, 2009, 03:59 PM
If I allow my voltage to drop below 12 volts [i.e. electric water pump running after engine turned off to reduce heat soak], I find that I have a hard time getting the car started again due to very lean readings on the wideband. Once the voltage comes up it richens back up to normal. Does anyone have a voltage profile for this injector to populate table b3701? Also, what is this table's role vs. b4002? Thanks for your help!

Bobby

LSX 455 CUI
Magnacharger 8.5 PSI
1999 C5 PCM
EFI Live custom 0S for Boost

5.7ute
March 24th, 2009, 07:24 PM
B4002 from what I understand modifies the IFR seen by the PCM in relation to pump voltage, whereas B3701 models the injectors opening & closing in relation to voltage.
so we have IBPW = airmass/AFR/(IFR*{B4002})+{B3701})
B4002 is easily modelled by measuring the fuel pressure under low voltage conditions. I am still working on an easier method of back calculating B3701 from a known good tune on standard injectors. Hopefully someone will have this data for you.

bobbycollier
March 25th, 2009, 03:47 AM
This is helpful info. So it seems that for "experimentation" purposes, it might be easiest to start with B4002. The voltage profile is the stock profile from a standard 2002 Corvette tune which is likely quite different from what the Racetronix requires. But I may be able to get the result I want with simply B4002 using your equation above. Thanks for the suggestions.

Bobby