Duramax 6.6L FJ80 ratios and size
- Thread starter TwoTonic
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Listed here @ 835 without clutch......
http://eogld.ecomm.gm.com/images/mediumduty/techspecs/engine.pdf
- Thread starter
- #23
Raydouble,
Great link! I'd never seen the spec'd weight before. It's going to be a bit heavier than the 3FE... but what a torque curve. We have the 300/525 spec'd version and it's got an incredibly flat curve.
Thanks for posting it
Raydouble,
Great link! I'd never seen the spec'd weight before. It's going to be a bit heavier than the 3FE... but what a torque curve. We have the 300/525 spec'd version and it's got an incredibly flat curve.
Thanks for posting it
No problem....... I assume you know about the injector "special policy" 04039A on the duramax's? Post #5 has good info.
7 years - 200,000 miles........ but if it is already out of the cheby, you may have some trouble getting warranty work done on it.
lol.... Ray brought the tech! cool.
- Thread starter
- #27
No problem....... I assume you know about the injector "special policy" 04039A on the duramax's? Post #5 has good info.
7 years - 200,000 miles........ but if it is already out of the cheby, you may have some trouble getting warranty work done on it.
Mine's a 2005.5 and is already out of the truck, so I can't take advantage but it's great info and we'll track it. Thanks again.
What transfer case are you going to use??
For that matter what axles are you going to use. That Dmax creates axle snapping power. I think the birfs are toast if you stick with them.
- Thread starter
- #31
Great questions-- I guess that's why we're in the planning stages... The thought was to use the GM transfer case from the 3/4 and 1 Ton series, saves an adapter and is known to take the torque. Will probably convert to the GM rear diff, and axles, which align with the T/C output (and means an after market fuel tank, probably...) .
Front axle is the big ???.
Please shoot arrows at this-- it feels like a project where we're going to be thwack'ing our heads a lot and going--
d60 from f350?
Is there anything besides that or a mog axle that will hold up to the torque?
not that comes to mind.
mog - interesting... rockwells? or hybrid portals?
mog - interesting... rockwells? or hybrid portals?
I was thinking the Rockwell 2-1/2 ton toploaders but I don't know enough about the two to say one or the other.
Both those are spendy options though.
I could also see custom 9 inch in the rear
I'm so envious of this whole project.
Yea, this will be one serious rig. the trick will be keeping the unsprung weight as low as possible.
- Thread starter
- #37
Maybe-- certainly tough enough. I keeping hoping that we can figure out something that will
a) handle the torque and
b) give us the option to move to taller gears
The front is going to be the challenge, given diff location and solid axle-- GM stuff is all IFS.
After seeing the post on the 300/525 TQ curve I'm even more convinced that taller gears would be helpful for highway driving-- Would hope to get over 25mpg there.
Even so, in LO range and short 1st gear-- should be monster off road.
Dana 60 3.54 Ring and Pinion (Yukon : YGD60-354)The Dana 60 is a common axle in many 3/4 and 1 ton trucks. The strength of this axle makes it desirable to swap into a vehic...[More Info] $296.23
Dana 60 3.54 Ring and Pinion (Reverse) (Yukon : YGD60R-354R)The Dana 60 is a common axle in many 3/4 and 1 ton trucks. The strength of this axle makes it desirable to swap into a vehic...[More Info] $464.08
Dana 60 3.73 Ring and Pinion (Yukon : YGD60-373)The Dana 60 is a common axle in many 3/4 and 1 ton trucks. The strength of this axle makes it desirable to swap into a vehic...[More Info] $273.87
Dana 60 3.73 Ring and Pinion (Reverse) (Yukon : YGD60R-373R)The Dana 60 is a common axle in many 3/4 and 1 ton trucks. The strength of this axle makes it desirable to swap into a vehic...[More Info] $452.77
you wont have a problem with the ratios in a D60.....
What about hybrid FZJ80/ Dana 60 or Ford 9 inch.
Although probably not advantageous unless you keep the stock tcase.
Although probably not advantageous unless you keep the stock tcase.
Really though I think that a dana 60 in the front, and if you have to go away from the stock rear axel, go for a 14bolt. Dana 60's can be had in both left and right offset fronts. Fords got high pinion drivers offset and dodge and chevy passenger low pinions. Chevy also for some time offered a Dana 61 with something like a 2.56 ring and pinion in an effort to get better milage in the 80's, however this didnt work well (see below).
Dana 60 rear ends are semi-float.
For this aplication a Dana 60/14 bolt with 3.73 and 33" tires I am willing to bet will net great milage and not be under reving the motor at speed. 4.10's for 35" tires would also be a good combo. I am very hesitant to say that you will get 25mpg (but you might) as a stock single cab long box 3/4 ton with a duramax is close to the same weight as an 80 only gets about 20-21 with a duramax. The emmisions stuff on these killed the milage, and so did the tourq wars with the diesel motors.
As as I said before our work truck, weighs in at 9,300lbs every day weight, has 33" tires with stock gears pulls 19mpg @ 75 and with a load of 15-25k (don't ask) behind will get 14 @55. This is a 07 classic (pre new body style) with the 650ft/lb and 6spd auto.
Best mpg are usualy IIRC found at 1600-1800 rpm. So that shoud be what you shoot for. Lower gears don't always mean more mpg. Often it is the reverse.
Dana 60 rear ends are semi-float.
For this aplication a Dana 60/14 bolt with 3.73 and 33" tires I am willing to bet will net great milage and not be under reving the motor at speed. 4.10's for 35" tires would also be a good combo. I am very hesitant to say that you will get 25mpg (but you might) as a stock single cab long box 3/4 ton with a duramax is close to the same weight as an 80 only gets about 20-21 with a duramax. The emmisions stuff on these killed the milage, and so did the tourq wars with the diesel motors.
As as I said before our work truck, weighs in at 9,300lbs every day weight, has 33" tires with stock gears pulls 19mpg @ 75 and with a load of 15-25k (don't ask) behind will get 14 @55. This is a 07 classic (pre new body style) with the 650ft/lb and 6spd auto.
Best mpg are usualy IIRC found at 1600-1800 rpm. So that shoud be what you shoot for. Lower gears don't always mean more mpg. Often it is the reverse.
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