ok so i have a 2000 f150 5.4 4x4 7700, and an edge programmer. i have differnt size tires from stock (stock 245/75/16 new 255/70/16) and i used my edge to correct my speedo and now that thats fixed my truck shifts at different spots. like it used to change into OD at like 42, 43. now it shifts and like 38,39 and at 50 im at 1500rpms. so my question is should i just change my OD shift point or all of them? also how much should i move them?


thanks

 

Out of curiosity, what did you enter for the new tire size? The size difference between your stock tires and your new tires is very small. In fact, the new tires are smaller, so that should increase the shift speed. However, I wouldn't think that difference alone would change the shift points that much. Also, did you change any other settings on the Evo? Last, what level did you use?

 

Just a hint to the wise, make sure you are using the correct gear ratio. The default ratio is not always what your truck really has.

 

Good call. I thought there might have been something I was missing.

 

the new size i put in was 2278mm, and i left the gear ratio alone because it said 3.73 which is what comes standard on the 7700 series. that is the only thing i changed and its on level two.

thanks for the replies

 

What's the tire size that's stamped on the side of your tire? I'm not doubting you, but the figure 2278mm seems small to me.

- Jack

 

Yeah, I'm doing just a quick calculation in my head, but I think 255/70/16 is closer to 2400 mm.

 

well the stamped tire size is 255/70r16. the original size i put in the edge was 2398mm and me speedo was of by like 4mph(so my speedo said 50 and the garmin gps said 46). so then i used a 5% squish factor and got 2278mm and my speedo is still like 1mph off according to the ol'gps. so now my truck shifts soon and im not liking that for highway gas milage

 

Keep in mind that your truck speeometer is always 2 or 3 mph fast at 65 mph. Comes that way from Ford.

 

so what do you think i should set it at?

 

I use the Edge digital speedometer as my speedometer. I never even look at the truck speedometer. So, I used a GPS to set the Edge exactly. It took about 4% off the calculted number to get it accurate. My truck speedometer is 3 mph fast at 65.

 

Yeah, just match your GPS to the Evo's speedo. My truck speedo is off by only 1-2 MPH at 65-70, but it is definitely different from the Evo.

 

so the edge mph is different from your speedo?

 

Yes, it is. The truck's dash speedo will read about 3% faster than you're actually moving if you have the correct tire size set in and the Edge speedo is dead accurate. This means at an actual speed of 70 mph, the dash speedo will show about 72-73 mph.

I've found a 3% squish factor works well for me when I have my tires inflated to spec. For your tires, this would be 2397 x 0.97 = 2325mm.

- Jack

 

thanks for the info, but thats another dilemma im having my door jam says 50psi in the front 60psi in the rear, and my POS tires only fill to a max of 44psi(which is what i have them inflated to). making this evan more annoying.