Tires: Tall and Skinnys? (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Building an HZJ79 0n a 1997 FZJ80 chassis with an R2.8 Cummins and NV4500 5spd/ 27% overdrive plus tire height. Turns out that there is a little calculator that matches engine perfomance/economy and torque curve,well the 255/85/16 Toyo comes in at 33.5" and offers peak economy and enters performance at 68 MPH with only 2047 RPMs. Mildly concerned about the 10 ply/ 80 PSI max but I will figure in a 40 gal fuel cell to add weight along with (2) spares. I opted for the 2.5" OME heavy lift to offset these items. Did I do it right? I will report back when I know. I am adding the wider Kutsnake flares to cover the additional track width.

View attachment 2326968

Do you have a link to the performance/economy/torque curve calculator? Thanks
 
Do you have a link to the performance/economy/torque curve calculator? Thanks


The calculator must be adjusted for your HP/TQ number based on % of R2.8 values, extremely accurate. Having just built an FJ45 on an 80 chassis with a stroker motor I plugged in the values and it is absolutely correct. Should probably put taller tires with all the new found torque? The calculator is at the bottom of the page on this site. R2.8 Turbo Diesel | Cummins Inc. Let me klnow what you think, L.
 
So I’m thinking about 25585r16 BFG KM3s this fall/winter (moving to SC by end of summer so all my discretionary spending is tied to that)
 
Building an HZJ79 0n a 1997 FZJ80 chassis with an R2.8 Cummins and NV4500 5spd/ 27% overdrive plus tire height. Turns out that there is a little calculator that matches engine perfomance/economy and torque curve,well the 255/85/16 Toyo comes in at 33.5" and offers peak economy and enters performance at 68 MPH with only 2047 RPMs. Mildly concerned about the 10 ply/ 80 PSI max but I will figure in a 40 gal fuel cell to add weight along with (2) spares. I opted for the 2.5" OME heavy lift to offset these items. Did I do it right? I will report back when I know. I am adding the wider Kutsnake flares to cover the additional track width.

View attachment 2326968


Not that it will change your calculation much, but those tires will actually measure out in real life to around 32.5" so will put you around 100rpms more :beer:

Can't wait to see the build!
 
Last edited:
Not that it will change your calculation much, but those tires will actually measure out in real life to around 32.5" so will put you around 100rpms more :beer:

Can't wait to see the build!


Did a hard measurement, the 285/75/16 Toy MT on my 45/80 are 32.47" tall and the 255/85/16 Toyo MTs are 33.5". So close, just waiting on my new NV4500 and T-case. May as well put the sound deadening in along with some seats.
 

Similar threads

Users who are viewing this thread

Back
Top Bottom