lightningspeed
Third Strike
what do I need to recalibrate the fmu to when changing from a 6 rib setup to a 8 rib? Thanks
recalibrate fmu for 8 rib
- Thread starter lightningspeed
- Start date
SBELTZ
Member
No, you do not need to do anything with your FMU when changing you pulley's from 6 to 8 rib even if you are changing the diameter. The FMU references the boost. If you make more boost then you FMU will up the fuel pressure that much more. The only time you should have to play with the FMU is if you change the injector size or if the initial calibration is wrong to begin with.
lightningspeed
Third Strike
ahh well I have gone from 19s to 30s so maybe I should change it 
SBELTZ
Member
Yes, if your FMU was originally calibrated for 19# injectors then you could be running a little rich at full boost. If you have access to a wideband O2 meter then it could tell you how your fuel curve is looking. A crude way to tell is look out the back or have someone follow you when you nail it. If it is rich, you can see it in the exhaust. In the old days before I purchased a wideband, I would do plug readings and watch an EGT gauge. I would do wide-open runs in my Mustang down the track. When I hit 5500 rpm in third gear, I would push the clutch in and kill the engine to get a true WOT plug readings. This was a crude reading but it got me close. Good luck with your calibration.
