Gryphon Programmer
Senior Member
Joined: Mar 2014
Posts: 210
Likes: 3
Follow up question, and maybe there is a post on this already, but adding my tires circumfrence in mm???? I have 275/60/20 which double check me, but that should be a circumfrence of 103.6". Then just convert that to mm???
So far I like the programmer, i can tell in the trans shifting for sure. Not so sure on the power, but the 87 tow does have good low end torque.
So far I like the programmer, i can tell in the trans shifting for sure. Not so sure on the power, but the 87 tow does have good low end torque.
former member
Joined: Jan 2014
Posts: 3,092
Likes: 857
Follow up question, and maybe there is a post on this already, but adding my tires circumfrence in mm???? I have 275/60/20 which double check me, but that should be a circumfrence of 103.6". Then just convert that to mm???
So far I like the programmer, i can tell in the trans shifting for sure. Not so sure on the power, but the 87 tow does have good low end torque.
So far I like the programmer, i can tell in the trans shifting for sure. Not so sure on the power, but the 87 tow does have good low end torque.
Those be 33" tahrs, eh?
( BTW, Falken's site lists these as: 275/60R20 = 33X10.50R20 )
Reckon the cipherin' be as sich:
33 inches x pi (3.14159) x 25.4 (inches to mm conversion) = circumference without weight on the tires. That initially gives ye: 2633.28 mm
Now - Multiply thet thar result by 0.97 to account fer the usual 3% "squish" caused by weight (hefty, aight?) which will give ye a real good startin' point of 2554 mm. Fine tune 'er 'til the Programmer's display speed (not the truck speedo) agrees with a GPS, if'n yall can.
Make sure yer Gear Ratio is correct whenever ye open thet thar custom options menu. It might need to be changed.
Good luck
MGD
Last edited by MGD; Apr 23, 2014 at 03:35 PM.
Senior Member
Joined: Mar 2014
Posts: 1,092
Likes: 147
Hi.
Those be 33" tahrs, eh?
( BTW, Falken's site lists these as: 275/60R20 = 33X10.50R20 )
Reckon the cipherin' be as sich:
33 inches x pi (3.14159) x 25.4 (inches to mm conversion) = circumference without weight on the tires. That initially gives ye: 2633.28 mm
Now - Multiply thet thar result by 0.97 to account fer the usual 3% "squish" caused by weight (hefty, aight?) which will give ye a real good startin' point of 2554 mm. Fine tune 'er 'til the Programmer's display speed (not the truck speedo) agrees with a GPS, if'n yall can.
Make sure yer Gear Ratio is correct whenever ye open thet thar custom options menu. It might need to be changed.
Good luck
MGD
Those be 33" tahrs, eh?
( BTW, Falken's site lists these as: 275/60R20 = 33X10.50R20 )
Reckon the cipherin' be as sich:
33 inches x pi (3.14159) x 25.4 (inches to mm conversion) = circumference without weight on the tires. That initially gives ye: 2633.28 mm
Now - Multiply thet thar result by 0.97 to account fer the usual 3% "squish" caused by weight (hefty, aight?) which will give ye a real good startin' point of 2554 mm. Fine tune 'er 'til the Programmer's display speed (not the truck speedo) agrees with a GPS, if'n yall can.
Make sure yer Gear Ratio is correct whenever ye open thet thar custom options menu. It might need to be changed.
Good luck
MGD
former member
Joined: Jan 2014
Posts: 3,092
Likes: 857
At highway speeds? That's more of a problem for dragsters, methinks, lol.
3% is just a 'median' starting point - squish can vary by tire carcass construction, inflation pressures and tire temperatures - and as you noted, speed.
The factors used are all compromises because tire diameter is so dynamic. Not worth being overly concerned aboot - that's why confirmation/correction by external means is advisable.
Cheers
MGD
Senior Member
Joined: Dec 2013
Posts: 544
Likes: 59
Topic at hand is gryphon...... You stated you are an sct guy right? By the way.... It was a compliment..... You are an internet wizz! Nice truck man, but would love to see an MGD sign in front of it..... Just say'n
Note the F150OL and Troyer Performance stickers (which should answer yer earlier question).... MGD
F150 Life
Joined: Mar 2010
Posts: 486
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From: Arizona