Need some speedo help

[CRZYDRVR]

Installed a new cluster w/ tach, but had to remove the needle to change out the odometer from my old cluster to keep the mileage right. I have it back on, but i think its reading a little fast.

I need RPM @ 45 and mabye 60MPH to see how far Im off. Should get me close enough. Traffic is bad enough around here that Im not excited about trying to follow someone and stick the needle on while Im driving.

Thanks a bunch.

[ButtonPuncher]

Good question. Both of my 'tours are currently broken.

If you can find a friend with a GPS, that's how I did mine. Set the cruise control and then stick it on.

HTH,
BP

[Trademark]

<~~ No Tach here.. :-) FWIW find a buddy and have him stick the needle on while you are driving:-) much safer..

[IRingTwyce]

If you have a diagnostic tool that gives real-time info, here's what you do:

Jack the car up on jackstands, put the car in gear, accelerate to a pre-determined speed, using the diagnostic readout as your guide, then stick the needle back on. Much safer than trying to do it cruising down the road, but not helpful at all if you don't have a diagnostic tool.

[Matt R]

I have to drive to a class today and I'll let you know my reading. However, I took off the tach and speedo needles before, but I know they are almost exact. I'll post back tonight.

[Matt R]

Ok here you go. This is the best I could do. I took a bunch of different speeds and readings to try to give you the best idea. The 35 is dead on steady at 1750, and same for the 70 at 2550.

Speed/RPM

0 (idle)/750-800
30/1750-1800
35/1750
45/2050-2100
60/2200-2250
65/2435
70/2550

[CRZYDRVR]

I appreciate the info. Im reading about 2250 at 50MPH so Im further off than I thought.

[ButtonPuncher]

Duh. I have a crapload of datalogs that I did with my xcal2 on my ATX Zetec. I can get you some EXACT info in just a few minutes...

EDIT Here ya go...

65MPH = 2500RPM
70MPH = 2700RPM
75MPH = 2900RPM

Please keep in mind that these are very close values but not exact afterall. I grabbed these values when cruizing (at part throttle). I found out at lower speeds, the values were all over the place. The torque converter really screws things up. At least with a MTX the transmission is locked to the engine.

BP

[pre98zetec]

i'm just a pinch above 2500 @ 65mph.

[CRZYDRVR]

Thanks BP. Mine now reads about 3 MPH high after moving it a little. Good enough for me.