Tire Size

[Power Hungry]

Originally Posted by svt2205

My speedo has been off since day one with my custom tunes...

My tires are 275/70-18...

Henry,

The reason your tire size is off is because on your custom order form you entered 275/75-18 instead of 275/70-18. This accounts for just over an inch in tire diameter (33.42" vs. 32.39") and will cause the speedo to be off quite a bit.

The current values in the calibration (as you've no doubt noticed) is 2669mm. The correct values should be 2584mm @ 5% squish and 2570mm @ 6% squish.

The files have been corrected and reloaded on the server. You can download then whenever it's convenient.

Take care.

[svt2205]

Jack

I read the FAQ but that point didn't click. Thanks for repeating that again.

Bill

That would explain it. Now what's the practical temperature limit for tuning? We've had the first real cold snap here in NH. Heck it's all of 35 right now and I don't think it got out of the 30's yesterday. Ugh, too soon for winter. (yes we've seen our first snow already)

As soon as it's warm enough, I'll return to stock and load the adjusted files.

Thanks for catching my mistake and better yet, FIXING it...

Henry

[88Racing]

Practical tuning temp?
You should be ok in the 30's.
Usually any temps in the teens and below you would want to run the truck first for 5 minutes.
Lars

[Power Hungry]

As Lars indicated, just run the engine a few minutes first. Since the PCM is located right above the engine, it'll warm up pretty quick. Ford specs say don't program below 30 degrees, but that relating to core PCM temps. If the engine has been run for a while, it's fine.

Glad we could get the other fixed easily.

Take care.

[Jackpine]

Originally Posted by Power Hungry

As Lars indicated, just run the engine a few minutes first. Since the PCM is located right above the engine, it'll warm up pretty quick. Ford specs say don't program below 30 degrees, but that relating to core PCM temps. If the engine has been run for a while, it's fine.

Glad we could get the other fixed easily.

Take care.

I'd also have the Gryphon in the house, before your programming session, so it's nice and warm too.

Glad things are squared away!

- Jack

[svt2205]

Great support from all of you for helping with what was my mistake from the get go.

Good to know all the details regarding cold temp tuning. I ruled out being able to adjust things during our 6 months of COLD. Now I've got a work around, if I need to swap tunes.

A big thanks to each of you.

Have a good one
Henry

[Jackpine]

Originally Posted by svt2205

Great support from all of you for helping with what was my mistake from the get go.

Good to know all the details regarding cold temp tuning. I ruled out being able to adjust things during our 6 months of COLD. Now I've got a work around, if I need to swap tunes.

A big thanks to each of you.

Have a good one
Henry

Henry, this was posted in an earlier thread and "approved" by Bill too. If it's cold, it doesn't hurt to have a low Amp charger (about 2 Amps) on the battery anytime you want to change the tunes. It will keep the voltage at the level needed for a proper update to the PCM. Low temperature tends to reduce the voltage output of even a fully charged battery, and this is a "work-around".

- Jack