Changing speedometer

[minytrker]

On trucks can you just type in the new size under the speedometer calibration to adjust for the new tire size?

[Banshee1973]

Yes that is correct.

[minytrker]

Thanks....On corvettes what else is there? I think the corvette is differnt because of where it gets it speed signal from.

[Blacky]

Thanks....On corvettes what else is there? I think the corvette is differnt because of where it gets it speed signal from.

See here:
http://www.ls1tech.com/forums/showthread.php?t=465396

Regards
Paul

[minytrker]

What about when someone installs new gears and tires. I just need to type in the new gear ratio and tire size?

[Blacky]

What about when someone installs new gears and tires. I just need to type in the new gear ratio and tire size?

Yes, you can enter both diff gear and tire size changes together, then click the recalculate button. Then click the [Save] button to copy the calculated results back down to the calibration data.

Optionally use the [Adjust] button to adjust shift speeds based on the altered ratio.

Regards
Paul

[minytrker]

Thanks for help. What happens if you dont adjust the shift speeds? Is it better just to adjust it?

[Blacky]

The reason the [Adjust] button exists at all is only because the gear shifts are calibrated as road speed (MPH) instead of engine RPM.

Assume your 1->2 shift is set to 35mph and assume that at 35mph in first gear, your engine is at 5600rpm.
Then you change your tire or diff gear or both so that at 35mph your engine speed is only 4500rpm. Your 1->2 shift would then occur at 4500rpm, which is not ideal.

You need to figure out what road speed corresponds to 5600rpm with the new tire/gear combination, so you can adjust your shift speeds to suit. That's what the Adjust button does for you. It recalculates all your shift speeds so that the shifts continue to occur at the same RPM.

You can choose to ignore the [Adjust] button and set up your shift speeds manually. Its only an aid to help figure out your shift speeds.
Hint: You can see the engine RPM displayed in the status bar at the bottom of the window whenever you click in a cell that contains mph.

One last thing, if your shift speeds are wrong before you change your tire and/or diff gears then the adjsut button will not correct the shift speeds. It calculates the adjustment assuming they were accurate to begin with.

Regards
Paul

[sweetdiesel]

Paul
is this regrding the allison as well..no right

[Blacky]

Paul
is this regrding the allison as well..no right

Not really, because the Alison calibrations exist in a different file.

You would need to do it manually. Just take note of the % adjustment, then apply that percentage to each of the shift tables in the Alison calibration.

Regards
Paul