70mph what rpm - Diesel Bombers

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70mph what rpm

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Old 08-12-2011, 12:00 PM
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Default 70mph what rpm

I was hopping you guys out there can let me know what your rpm is at 70 mph and what tire size and gears you got this would help me out I'm trying to see if I have to low of gears
 
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Old 08-12-2011, 12:25 PM
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1700rpm @ 70mph with 34" tires, 4.10 gears and the Gear Vendor in 5th over.
 
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Old 08-12-2011, 12:38 PM
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2009rpm @ 70mph with 32" tires, 3.55, and stock G360 in fifth
 
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Old 08-12-2011, 12:42 PM
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Gear vendor lucky!!! I don't have the room for one

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Reason I'm asking is cause I got 37" tires 4.10 and at 60mph I'm doing 2000 rpm and I don't want to hurt my motor but I would like to go 70
 

Last edited by cumminsblazer; 08-12-2011 at 12:42 PM. Reason: Automerged Doublepost
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Old 08-12-2011, 12:45 PM
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They weren't meant for speed to begin with...I keep mine at 65mph for the most part on interstates and such

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but if you can find a cheap 3.55 rearend then go for it just make sure you get one for the front end too if its 4x4
 

Last edited by Glantz496; 08-12-2011 at 12:45 PM. Reason: Automerged Doublepost
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Old 08-12-2011, 01:27 PM
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12V VE cummins will run 2,500 rpm all day long, all week long, all month long.
 
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Old 08-12-2011, 01:40 PM
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Originally Posted by cumminsblazer View Post
Gear vendor lucky!!! I don't have the room for one

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Reason I'm asking is cause I got 37" tires 4.10 and at 60mph I'm doing 2000 rpm and I don't want to hurt my motor but I would like to go 70
Is that correct? The reason I ask is because the ratio/rpm calculators out there always put my motor at 2000 RPMs at 60 MPH with 235/85R/16 tires with 4.10 gearing in 5th with G360 trans? With 37" tires and 4.10s I would think you would be at a lower RPM than 2000 unless your gearing has been changed to lower than 4.10
 
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Old 08-12-2011, 01:49 PM
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automatic trans maybe
 
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Old 08-12-2011, 02:06 PM
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Originally Posted by sootnsmoke View Post
I would think you would be at a lower RPM than 2000 unless your gearing has been changed to lower than 4.10
Yeah, something don't sound right. I'd think an OD trans much more than 1-1 in top gear would get the final drive rpm down better than that with 37" tires.
 
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Old 08-12-2011, 08:26 PM
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when i did my swap the truck had 4.10 gears with the a518 and yes about 60 mph it is about 2000 rpms is right, for pullin my 5th wheel it was nice. but daily driver it sucked, i put in some 3.73s now its about 1800 @ 70 mph,not so good for pullin but OK. i then tried 3.54s, it will flat haul *** but pullin sucked, (if you don't plan on pullin anything then i would go with them. to get the 3.54s in the back i put in a Dana 60 (14bolt does not have 3.54 option ) I went back to the 3.73s for all around use. 60 mph is about 1600 rpms in O/D hope this jiberish makes sense
 

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