Quick simple question

[samh_08]

I do not have a stock speedo because I transplanted a LQ4 into my 86 monte. My question is..What do I have to change so the PCM sees the correct pulses per mile? I would assume the speedo calc and fine tune are for stock vehicles, right?

The 2 variables that are not stock are my rear axle ratio (4.10) and my rim.tire size (26.61" diameter I believe)

Please get back to me, Thanks.

[wadesns]

If you look in speedometer/parameters there is a place where you can click speedo calculator. Fill in the correct fields then click apply. Save the bin then load and hopefully this will work. If not you will need to determine how many pulses per mile your speedometer reads then do the math to recalibrate based on the speedometer.

[samh_08]

Calibrating the speedometer is a non issue. It is an Auto meter so I can program it for anything. What I need to know is how to calibrate the PCM for my smaller tires and different axle ratio. I just need the PCM to have the right pulses per mile for my application..