Truck speed?

[2stacksuperdog]

Ok so we're looking at a '85 with a 285, 2stick 6 speed, and 4.64 rears. Was suppose to have tubetype tires on it. Has 11r24.5s on it now. Goodyear also makes a 11r24.5 that is the g182 which is larger then a regular 11r24.5. Was wondering what the speed would be with regular 11r24.5s vs. 12r24.5s?

[fullfuel01]

Same, 12r22.5 are the same height of a 11r24.5

[2stacksuperdog]

We got a r with 11r24.5s with a direct 6 on 4.17s and it goes 75-80.

[Bigdogtrucker]

Sounds like it'll be fast enough.

[Vladislav]

The most precision answer to your question might be recieved if you ask Goodyear on those tire's actual OD's wich used to be different of their size markings. Than do an easy math dividing your today's speed by less OD and multiplying with the lager.

[Vladislav]

By the word 12R24.5's must be wider than 11R24.5's and not taller.

Just found out recently 12R24.5's exist, haven't put my eye or hand on them yet.

[2stacksuperdog]

Sounds like it'll be fast enough.

I'll be happy with 65

[2stacksuperdog]

For a g182 Goodyear the diameter is 44.1 in.

[2stacksuperdog]

Used road rangers calculator. Put a 1:1 ratio with 11r24.5s. According to that it wil go around 58 at 2100. I wonder how accurate that is cause our rd does 70 at 1700 with 4.42s and a 8ll. According to that chart it should only go like 49 or so.

[Bigdogtrucker]

12R24.5's are a bit taller and wider.

[j hancock]

Used road rangers calculator. Put a 1:1 ratio with 11r24.5s. According to that it wil go around 58 at 2100. I wonder how accurate that is cause our rd does 70 at 1700 with 4.42s and a 8ll. According to that chart it should only go like 49 or so.

70 mph is correct with an 8LL with a .74 overdrive. Actually 68 mph, but close enough.

(1700 rpm X 44") divided by (3.2708 X 336) 4.42 with a .74 OD gives an effective final ratio of 3.27

The calculation of 58-59 mph for the other truck is correct.

[2stacksuperdog]

70 mph is correct with an 8LL with a .74 overdrive. Actually 68 mph, but close enough.

(1700 rpm X 44") divided by (3.2708 X 336) 4.42 with a .74 OD gives an effective final ratio of 3.27

The calculation of 58-59 mph for the other truck is correct.

Interesting cause they list the 8 ll as a 1:1 ratio.

[j hancock]

Here is the calculation

1700 rpm

44" tire

4.42 gear ratio (1/1 direct transmission)

336 is the mathematical constant taking into account pi, distance and time so you can figure miles per hour.

(1700 X 44) divided by (4.42 X 336) = 74,800/1485.12

which is 50.3663 mph.

[j hancock]

Interesting cause they list the 8 ll as a 1:1 ratio.

The lightweight RT-8908LL is direct but the RTO-11908LL, 14908LL and the 16908LL have a .74 overdrive.

[j_martell]

In the service manual I have for newer road Rangers is lists most of them as over or direct, identified in the model # by "o" and "x". Ex. RTO would be over, and RTX would be direct....

The same may not be true for older designs....I'm not so well versed in the old ones:)

[MHfred]

In the service manual I have for newer road Rangers is lists most of them as over or direct, identified in the model # by "o" and "x". Ex. RTO would be over, and RTX would be direct....

The same may not be true for older designs....I'm not so well versed in the old ones:)

Eaton lists my RTX-11609B in my 89 MH as .73 over. I have a page from their website that says the "RTX = w/overdrive and direct shift pattern"

[j_martell]

ah.....perhaps, and this is a long shot.....i misunderstood.....lol

my wife has the tablet in the hospital with her, but when i get it back, ill re-read it.....

i do recall something about the shift pattern in the code......but my memory is not so good......