If your speedo is off I highly recommend getting the Ford Racing speed-dial speedomter adjuster. My DM speedcal is now in my trash can and here is why.
I recently did 4.10's and of course my speedo as off. I had a DM speedcal which I installed, was a little bit of a pain because you have to repin connectors while lying under the car but did it correctly.
Set the 10 DIP switches as indicated in the install sheet, test drove, speedo still way off. Went to Dallas Mustang website, got a different DIP switch setting, changed, still off.
Called DM, was told to talk to Justin, he gave me another code, still off. Call again, another code, still off. Four more times, still off.
Just to let you know how each was tested I reset my trip odometer, drove EXACTLY 10 miles measured by GPS then wrote down the displayed miles and gave that to Justin. Also I could see with each test my GPS speed compared to my speedo so I knew it was off immediatly.
At this point I was beyond annoyed, went online and bought the Ford Racing speed-dial, as soon as I looked at the instructions I knew it was a better product.
First off no repinning connectors, all you do is splice one wire on the VSS sensor. It does require both a power and ground while the speedcal only needs power, big deal.
Second plus, if you leave all the dials on 0-0-0 (default out of the box setting) as soon as you turn your key on your speedo will go to 45MPH and hold there showing your wiring is correct.
Now for the best part, instead of 10 DIP switches the speed-dial has three rotary switches, you simply dial in the ratio you want. In my case it was 3.27(old)/4.10(new)=.797, they say to round so I went to .80 and set dials at 0-8-0, drove and almost perfect, changed dial to 0-7-9, right on the money. No calling for mystery DIP settings, just simple adjustment and done.
So for right about $130 I highly recommend you go Ford Racing and dont even consider buying a DM speedcal
I recently did 4.10's and of course my speedo as off. I had a DM speedcal which I installed, was a little bit of a pain because you have to repin connectors while lying under the car but did it correctly.
Set the 10 DIP switches as indicated in the install sheet, test drove, speedo still way off. Went to Dallas Mustang website, got a different DIP switch setting, changed, still off.
Called DM, was told to talk to Justin, he gave me another code, still off. Call again, another code, still off. Four more times, still off.
Just to let you know how each was tested I reset my trip odometer, drove EXACTLY 10 miles measured by GPS then wrote down the displayed miles and gave that to Justin. Also I could see with each test my GPS speed compared to my speedo so I knew it was off immediatly.
At this point I was beyond annoyed, went online and bought the Ford Racing speed-dial, as soon as I looked at the instructions I knew it was a better product.
First off no repinning connectors, all you do is splice one wire on the VSS sensor. It does require both a power and ground while the speedcal only needs power, big deal.
Second plus, if you leave all the dials on 0-0-0 (default out of the box setting) as soon as you turn your key on your speedo will go to 45MPH and hold there showing your wiring is correct.
Now for the best part, instead of 10 DIP switches the speed-dial has three rotary switches, you simply dial in the ratio you want. In my case it was 3.27(old)/4.10(new)=.797, they say to round so I went to .80 and set dials at 0-8-0, drove and almost perfect, changed dial to 0-7-9, right on the money. No calling for mystery DIP settings, just simple adjustment and done.
So for right about $130 I highly recommend you go Ford Racing and dont even consider buying a DM speedcal