U7193 software Tire calibration correct?

[AVderek]

jonathanalberto007 try setting your tire size to 285/55/20. By setting a taller tire should match the speed to what your above.

[jonathanalberto007]

Thanks Avderek. I'll try that and see if I get close to the actual speed.

[fish_guy25]

bro, i had a similar problem with the 37" tires on my z-71. the tires were too big for the programmer to compute. what I did was figure out the size ratio of my original stock tires to my 37" tires. then i chose a smaller stock GM tire (that comes on 2 wheel drive trucks) and used that as the stock tire in the program. then i chose the largest stock GM tire (a 35" tire) and used that as the "tire" that I had on the truck. although both tire sizes were not right for my truck, the SIZE RATIO (ie difference in tire sizes) was the same difference as the ACTUAL stock tires to the NEW 37" tires. i hope that helps. everytime i try and explain that to people, half of them can't follow me.

[jonathanalberto007]

Fish guy25,

You idea works really well, but like you mentioned at the end, I got lost. Care to explain in numbers?

[Grumpy_Aero_Guy]

Honestly, I am surprised that a stock speedo with stock settings is only 3mph off at 80. That's on the order of a 4-5% error. I didn't think they were that accurate to begin with.

[CANUCKPREDATOR]

Hey guys,

Does the 7193 have an input for the stock tire size? All the 7194 has is input for tire size in either dimensions or diameter. I don't know of a setting like the in the 7194 and I have never been able to get my tire size input to get speedo correct. And surprise, I think understand your math.

[jonathanalberto007]

Canuckpredator,

Negative it does not have a stock tire size setting, only the actual tire size setting. Funny I got lost half way his explanation. Wanna explain what he said?

[CANUCKPREDATOR]

Canuckpredator,

Negative it does not have a stock tire size setting, only the actual tire size setting. Funny I got lost half way his explanation. Wanna explain what he said?

See that's were things come apart for me. I thought that your programmer could enter the stock tire size to base some calculations on. If that was the case, I had it figured out, but that shoots that all to pieces.

I used a website http://www.1010tires.com/tiresizecalculator.asp to find out the diameter of my tires (305/55/20=33.2" diameter), stock tire (265/70/17=31.6" diameter) and figured a size ratio for those two tires. But if you can't enter "a stock tire size" then you can't enter something that the same size ratio, just a smaller size that the programmer can understand.

[jonathanalberto007]

Canuckpredator,

Correct, even finding a size ratio it is still off, may be I got gremlins in my truck or unit. Who knows, but it feels great to have a diablo predator sport as a tune.

[swillia2]

Guys, I tht I read somewhr that the old Rev of the U7193 had stock size and new size whr the new Rev only have new tire size.. I think they maybe plugging in the stock size for you? Not for sure but tht I read that...