installed xfi cam should i install ecm

[randall 37382]

installed xfi cam, only slight mpg gain. 1-1.5 mpg gain fist tank, xfi parts car is a 1990 and has egr system with no vacume advance. driving 91 no egr with vacume advance. will the ecm work with different system THANKS FOR YOUR HELP

[Woodie83]

The biggest advantage of the XFI cam is that it allowed the engine to work with a much taller gear ratio. The gears are what provided most of the mileage increase, the improved torque curve merely worked with it.

[randall 37382]

THANKS WOODIE i have notist it pulls hills with less stain. i have read conflicting info on the gear ratio's between the xfi and metro-lsi . some say xfi has taller gear and some say the metro-lsi gearing is taller. im driving metro with lsi motor and trans with xfi cam. i happen to have one of each, im just tring to get the best combination. the lsi has been rolled /xfi has bottom end problem and body damage. the metro is in best shape so im tring to get the best possible car any info would be appreciated thank RANDALL

[Woodie83]

XFI had 3.79 final gear ratio
Convertable had 4.39
All other 89-94 had 4.10

The 98 - 01 four cylinder cars also have 3.79 if you're planning a junkyard shopping trip. Or, just get 13" wheels.

[randall 37382]

thanks WOODIE i'll check and make sure the x fi has original trans and hopefully change it out soon. if i change trans will the instrument cluster read correctly or do i need to change it as well thanks again RANDALL

[Woodie83]

Nope, the speedo gears are inside the transmission, as long as you don't change wheel diameter the speedo/odo will remain correct.