2nd Gen Non-Engine/Transmission if i run 35's tires and 4.10s?

[CATCRACKER]

i am looking to lower my rpms with increasing tire size how much of an effect will going from 235/75's to a 35's tire will it make in my rpms? can i run 70mph as 2000rpms? i have to stay out of the 2100 tp 2250 rpm range b/c of exhaust drone. with this help mpg or not. /



thanks

 

[biggy238]

I'm running 70 at roughly 2000 with 3. 54/3. 55 (which are these trucks anyway?) so you would be somewhat above that. They will hurt mileage slightly. I get about 17mpg in the mountains and lost some top end acceloration. I'm thinking a 3. 73 or 3. 88 gear ratio would be a good balance between power and speed. I don't know what ratios are available for these trucks and rearends.

 

[starring]

i am running 285's which are a little smaller than 33's with stock gears and at 2000 Rpm's i run 75 MPH. Not sure if this helps

 

[lrox]

I have 4. 10 and run 35's and I think it runs about where you want, my speedo is not calabrated.

 

[edgrim]

I run 315/70R17 BFG's with new 4. 10 gears I changed because my stock 3. 54 gears were too doggy from a stop. However I didn't have any engine bombs yet. I fixed my drone with a Silverline 4" exhaust and an aeroturbine,sounds sweet. I think once I get my timing done and add 370 injectors I might look at 3. 73 gears or 37" BFG's or maybe a KSBB1 or ... ... .....



Our trucks are similar PM me and give you any help I can. eg

 

[Tcolesanti]

I have 3. 54's and 315/75/16 Pro-Comp All-Terrains and I run 76-77mph at 2000rpm.

 

[CATCRACKER]

so 4. 10's and 255/85 or 285/75 what rpm @70mph 2050?

 

[pwerwagn]

I have 285's and 3. 55's and turn about 2250 at 75mph.

Only available gears for the dana 80 is 3. 55, 4. 10 and lower.

www.onlineconversion.com has a calculator somewhere (go to misc then automotive) that will tell you rpm @ speed. you need to know trans ratio, x-case ration (1:1) and gear ratio.

 

[woodsrat]

catcracker



I run 4. 10's and 255/85's on my dually at 70mph im turning around 2100.

 

[CATCRACKER]

woods,



thanks i guess i can go about 65-68 and be out of the drone zone and get a little better mpg. i figure on the 3hour trip if i go 68 instead of 75 i can will only lose about 20min or so and probably pic up 1. 5mpg or so. anyway thanks for the info! looks like if i go with the 35" tire i will get close to my desired results.

 

[NVR FNSH]

I turn 66mph (according to GPS) at 2000 RPM - 4. 10s & 6spd. Your auto has a taller OD IIRC so at 2000 RPM you'd run a slightly faster MPH.



How are you running 35s on a dually?



Brian

 

[Forrest Nearing]

man, I'm tellin' ya... invest some time and money in some sound deadener!!! even if you do go w/ the 35's, you'll LOVE the difference!!!



Forrest

 

[pwerwagn]

How are you running 35s on a dually?

255/85/16's are 33's, not 35's.

but you can run 35's on a dually. JGheen runs 37's on his dually. There is even a dodge V-10 running 49's on a dually. It a matter of spacer/wheel/tire width combo (except in the case of the 49's, then its axle width too)