Powerstroke Cowboy
Well-known member
Ok.. Carbon fiber looks good... Some of the new cub Airplanes have a bit of carbon fiber for strength but still be light...
If you do a set post pictures that would be cool!!
My tow pig/DD build thread. F350/Cummins 6.7/twins/6R140
- Thread starter me2
- Start date
Ok.. Carbon fiber looks good... Some of the new cub Airplanes have a bit of carbon fiber for strength but still be light...
If you do a set post pictures that would be cool!!
I'm back. I've been on holidays with my family since early July, only being back home to attend a wedding that fell in the middle.
In case you haven't noticed, I don't mention when I am leaving, nor where I live. I've had one truck stolen and that was quite enough. There has been a rash of Superduties gone missing in my area and I suspect that at least one was related to someone posting travel information on the Internet.
Our family has had a fantastic time at several lakes over the past couple weeks. In total we put about 2000 miles on my F350, about 800 of those pulling the trailer.
This is how we roll and stay when on the road these days.
The sailboat in front of the truck gets pulled behind on the hitch aft of the rack. The rack also folds up, which then allows me to use the hitch receiver under the rack. The "train", as my wife calls it, is over legal lengths either way, though I have never been bothered by law enforcement.
There is only 1 kayak on the roof in this picture. Usually there are 2 or 3.
Its absolutely amazing how well this sort of combination works. We are surprisingly comfortable and self sufficient when travelling and having all our gear along means we are never wanting for something to do.
In general my F350 has worked well, aside from my usual complaints of it being under powered (under torqued, actually) and it rides rough on bad roads. Not to mention its terrible fuel economy. Did I mention terrible ? Absolutely terrible.
The rear seat DVD player is a Godsend when travelling with kids. Put in a good disk and the hours and miles slip away while the kids listen to their shows on the wireless headphones while my wife and I enjoy silence or another media in the front seats. When I bought the truck I thought the rear seat DVD player was a nice to have. Now I think its essential.
An issue has cropped up with my truck. It has a terrible vibration and shake under various conditions, mostly to do with turning under load. I'll be checking the U Joints, rear diff limit slip and maybe even changing transmission oil this week.
Due to various commitments for both the truck and me, the swap itself is pretty much on hold until September now and work on swap fabrication is on hold until the CNC plasma cutter is done. Some/most of the parts arrived for the cutter while I was away, but I have a lot of catch up to do from being away before I'll be able to start piecing them together.
I'm sorry I don't have anything better to report. I'm bummed that I didn't have the 6.7 running before the summer use started, but I'm having too much fun enjoying the summer to let it bother me.
I can't wait to get the CNC cutter running and doubley can't wait to get a Cummins running in this thing.
In case you haven't noticed, I don't mention when I am leaving, nor where I live. I've had one truck stolen and that was quite enough. There has been a rash of Superduties gone missing in my area and I suspect that at least one was related to someone posting travel information on the Internet.
Our family has had a fantastic time at several lakes over the past couple weeks. In total we put about 2000 miles on my F350, about 800 of those pulling the trailer.
This is how we roll and stay when on the road these days.
The sailboat in front of the truck gets pulled behind on the hitch aft of the rack. The rack also folds up, which then allows me to use the hitch receiver under the rack. The "train", as my wife calls it, is over legal lengths either way, though I have never been bothered by law enforcement.
There is only 1 kayak on the roof in this picture. Usually there are 2 or 3.
Its absolutely amazing how well this sort of combination works. We are surprisingly comfortable and self sufficient when travelling and having all our gear along means we are never wanting for something to do.
In general my F350 has worked well, aside from my usual complaints of it being under powered (under torqued, actually) and it rides rough on bad roads. Not to mention its terrible fuel economy. Did I mention terrible ? Absolutely terrible.
The rear seat DVD player is a Godsend when travelling with kids. Put in a good disk and the hours and miles slip away while the kids listen to their shows on the wireless headphones while my wife and I enjoy silence or another media in the front seats. When I bought the truck I thought the rear seat DVD player was a nice to have. Now I think its essential.
An issue has cropped up with my truck. It has a terrible vibration and shake under various conditions, mostly to do with turning under load. I'll be checking the U Joints, rear diff limit slip and maybe even changing transmission oil this week.
Due to various commitments for both the truck and me, the swap itself is pretty much on hold until September now and work on swap fabrication is on hold until the CNC plasma cutter is done. Some/most of the parts arrived for the cutter while I was away, but I have a lot of catch up to do from being away before I'll be able to start piecing them together.
I'm sorry I don't have anything better to report. I'm bummed that I didn't have the 6.7 running before the summer use started, but I'm having too much fun enjoying the summer to let it bother me.
I can't wait to get the CNC cutter running and doubley can't wait to get a Cummins running in this thing.
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You know guys - valve covers are really easy to make... especially if you need just a little bit of clearance in a location and it doesn't actually interfere with any of the valve train. Just a little food for thought.
I never even thought of doing that. Thanks for sharing.
What did "they" use for the mold ? Is there a thread somewhere describing the process ?
Did they use a Cummins base and put on a new top ?
FWIW, at this point my biggest fear with everything about the swap is making it fit into the engine compartment, especially with the twin turbos on the passenger side. Nothing else is jumping out at me as being a show stopper. Thus my interest in a low profile valve cover.
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Hotrodtractor
Moderator
"They" built a mold using wood, final fit some of the surfaces with body filler, painted it and clear coated it. The similar fiberglass parts I have been apart of constructing (first hand - not second like this valve cover) - I used a carnauba wax for a release agent. No there is not a build thread. In fact I believe these will be available for sale at some point in the future from a Cummins based performance shop here in Ohio. This piece is 100% made from scratch to be a bolt on part.
Why don't I just buy a Dodge truck and "be done with it" ?
I don't want to start a debate on this issue, just share some insight into why I am doing the swap rather than buying a Dodge truck.
Each to their own. I spent the weekend parked beside a 2012 Dodge 3500 Megacab dually. They are very nice. I can see why people like them.
Here are some weights from our setup, loaded, full of fuel, some water in the tanks, me and our dog in the cab.
Front axle 5,170 pounds
Rear axle 5,852 pounds
Truck Total 11,022 pounds
Trailer axles 11,176 pounds
Total combination weight 22,200 pounds.
This doesn't include a second trailer that we might pull behind the 5er.
1) Payload
The 2012 Ram trucks have a maximum GVWR of 10,100 pounds as a SRW and 10,500 pounds in a Mega Cab DRW.
The GVWR on my 08 F350 is 11,500 pounds and its SRW.
The pin weight on my 5er is about 2500 pounds, depending on how its loaded. Depending on how you define empty, my F350 weighs about 8200 pounds, leaving a payload of 3300 pounds.
Dodge advertises the SRW MegaCab as having a payload of 2530 pounds based on a 10,100 pound GVWR. That implies it has an empty weight of 7570 pounds, which I find hard to believe. If it does truly weigh that, my F350 has a lot more steel in it.
I'm not sure what the limiting factor is when it comes to the Dodge GVWR, but I find it troubling that it is so much lower than the Ford GVWRs.
Some people say that these are just numbers and they don't matter. If they don't really matter then I would like Dodge to put different numbers in their brochures and cab stickers.
In any event, I'd have payload issues using even a DRW MegaCab 3500 to pull my trailer.
2) GCWR
The highest GCWR available on a MegaCab with a 3.73 axle ratio is 21,000 pounds, leaving a maximum trailer tow weight of 12,950 pounds. Here they are saying the truck will weigh 8,000 pounds.
The maximum GCWR on a MegaCab DRW with the 4.10 axle ratio is 24,000 pounds.
The stock GCWR on my '99 F250 7.3 ZF6 3.73 was 20,000 pounds ! It weighed 7,000 pounds empty, leaving a trailer weight of 13,000 pounds.
The stock GCWR on my 08 F350 SRW 6.4 auto 3.73 with 20 inch tires is 23,500 pounds. Its rated to pull a 15K trailer.
The stock GCWR on a 2012 F350 SRW 6.7 auto is 23,500 pounds with the 3.31 and 3.55 axles and 30,000 pounds (!) with the 3.73s. You can't even get 3.73s without going to a dually in a 2012 Ford.
I am very happy my 08 has 3.73s. With a built Cummins 6.7 and the 6R140, it should be good, power wise anyway, for a GCWR of nearly 30K.
I do not want a dually if I can avoid it and I certainly don't want a 4.10 axle.
Again, I am not sure what the limiting factor is when it comes to the GCWRs of the Dodge trucks. It certainly isn't limited by the engine as the 6.7 is used in motorhomes with a GCWR of over 30,000 pounds as well as a rating of 30K in the regular cab LB DRW trucks with 4.10 axles.
3) Transmission Issues
I do not believe the 68 RFE is as strong as the 6R140. I do not believe the 68RFE would withstand towing my trailer with a built Cummins 6.7.
4) Box length
I really wanted a long box truck this time, for cargo capacity. You cannot get a Mega Cab with a long box.
5) Tires and Rims
I am very partial to 20 inch tires on SRW trucks. You cannot get them on a factory Dodge truck.
6) Cost
Dodge trucks sell at a premium to Ford trucks, similarly equipped. Furthermore, I don't care for the interiors on the pre 2010 Dodge trucks, so I would have been forced to find a used 2010+ Dodge 3500 MegaCab, which would have cost a lot more than my F350 did.
7) Towing Mirrors
I love the Ford 08+ towing mirrors, especially the power folding mirrors on my F350.
I'm not saying my F350 is a perfect truck. It just works better for me and my application than some other trucks do.
I don't want to start a debate on this issue, just share some insight into why I am doing the swap rather than buying a Dodge truck.
Each to their own. I spent the weekend parked beside a 2012 Dodge 3500 Megacab dually. They are very nice. I can see why people like them.
Here are some weights from our setup, loaded, full of fuel, some water in the tanks, me and our dog in the cab.
Front axle 5,170 pounds
Rear axle 5,852 pounds
Truck Total 11,022 pounds
Trailer axles 11,176 pounds
Total combination weight 22,200 pounds.
This doesn't include a second trailer that we might pull behind the 5er.
1) Payload
The 2012 Ram trucks have a maximum GVWR of 10,100 pounds as a SRW and 10,500 pounds in a Mega Cab DRW.
The GVWR on my 08 F350 is 11,500 pounds and its SRW.
The pin weight on my 5er is about 2500 pounds, depending on how its loaded. Depending on how you define empty, my F350 weighs about 8200 pounds, leaving a payload of 3300 pounds.
Dodge advertises the SRW MegaCab as having a payload of 2530 pounds based on a 10,100 pound GVWR. That implies it has an empty weight of 7570 pounds, which I find hard to believe. If it does truly weigh that, my F350 has a lot more steel in it.
I'm not sure what the limiting factor is when it comes to the Dodge GVWR, but I find it troubling that it is so much lower than the Ford GVWRs.
Some people say that these are just numbers and they don't matter. If they don't really matter then I would like Dodge to put different numbers in their brochures and cab stickers.
In any event, I'd have payload issues using even a DRW MegaCab 3500 to pull my trailer.
2) GCWR
The highest GCWR available on a MegaCab with a 3.73 axle ratio is 21,000 pounds, leaving a maximum trailer tow weight of 12,950 pounds. Here they are saying the truck will weigh 8,000 pounds.
The maximum GCWR on a MegaCab DRW with the 4.10 axle ratio is 24,000 pounds.
The stock GCWR on my '99 F250 7.3 ZF6 3.73 was 20,000 pounds ! It weighed 7,000 pounds empty, leaving a trailer weight of 13,000 pounds.
The stock GCWR on my 08 F350 SRW 6.4 auto 3.73 with 20 inch tires is 23,500 pounds. Its rated to pull a 15K trailer.
The stock GCWR on a 2012 F350 SRW 6.7 auto is 23,500 pounds with the 3.31 and 3.55 axles and 30,000 pounds (!) with the 3.73s. You can't even get 3.73s without going to a dually in a 2012 Ford.
I am very happy my 08 has 3.73s. With a built Cummins 6.7 and the 6R140, it should be good, power wise anyway, for a GCWR of nearly 30K.
I do not want a dually if I can avoid it and I certainly don't want a 4.10 axle.
Again, I am not sure what the limiting factor is when it comes to the GCWRs of the Dodge trucks. It certainly isn't limited by the engine as the 6.7 is used in motorhomes with a GCWR of over 30,000 pounds as well as a rating of 30K in the regular cab LB DRW trucks with 4.10 axles.
3) Transmission Issues
I do not believe the 68 RFE is as strong as the 6R140. I do not believe the 68RFE would withstand towing my trailer with a built Cummins 6.7.
4) Box length
I really wanted a long box truck this time, for cargo capacity. You cannot get a Mega Cab with a long box.
5) Tires and Rims
I am very partial to 20 inch tires on SRW trucks. You cannot get them on a factory Dodge truck.
6) Cost
Dodge trucks sell at a premium to Ford trucks, similarly equipped. Furthermore, I don't care for the interiors on the pre 2010 Dodge trucks, so I would have been forced to find a used 2010+ Dodge 3500 MegaCab, which would have cost a lot more than my F350 did.
7) Towing Mirrors
I love the Ford 08+ towing mirrors, especially the power folding mirrors on my F350.
I'm not saying my F350 is a perfect truck. It just works better for me and my application than some other trucks do.
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What kinda mileage are you getting from your 6.4 ? Is it DPF deleted ? What kinda mileage are you expecting from the 6.7 ?
I'm in about the same boat as you are, have a big ass trailer to pull around. My horse trailer isn't as much of a wind block as your rig is but mine is heavier. I keep thinking 4.10's
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I'm in about the same boat as you are, have a big ass trailer to pull around. My horse trailer isn't as much of a wind block as your rig is but mine is heavier. I keep thinking 4.10's
Sent from my DROID RAZR using Tapatalk 2
8-8.5 MPG is what I am seeing, under very good conditions.
I am generally driving less than 64 MPH. It doesn't seem to get better even at 60 MPH. Its hard to drive 60 MPH when you are going 400 miles.
Its totally stock.
10+. I don't think my F250 (5.9CR, ZF6) ever really got less than 10 MPG pulling this trailer.
I don't really consider this a big, big trailer. There are lots that are bigger than mine. The high end 5ers are all 2-3000 pounds heavier than mine and then there are the triple axle toy haulers.
My approach is to build a torque monster engine and use the 1st OD gear on the 6R140.
My 20 inch tires are 605 revs per mile or thereabouts.
605 revs per mile x 3.73 x 0.86 = 1950 RPM at 60 MPH, 2100 at 65 MPH and 2260 at 70 MPH.
Lets say the engine is making 1000 ft/bs.
At 60 MPH, 1000 x 1950RPM / 5252 = 371 HP.
At 65 MPH, 1000 x 2100 / 5252 = 399 HP.
That should be more than enough HP at cruise and the RPMs are right in the sweet spot as far as I am concerned.
The only transmissions that I could find that have this sort of overdrive gearing are the 6R140 and the 68RFE.
By comparison, with a ZF6, 4R100, 5R110, the Allisons, etc, all have OD at about 0.71 and the next gear under it is direct. (1.0)
In OD (0.71) at 60 MPH you have
605 x 3.73 x 0.71 = 1602 RPM. Which is lugging for most engines.
In direct you have
605 x 3.73 = 2250 at 60 MPH, 2444 RPM at 65 MPH and 2632 RPM at 79 MPH.
2250 at 60 MPH is OK, but the rest is a bit fast for me. Fuel consumption seems to go up a lot at higher RPMs, loaded or unloaded.
4.10s and smaller tires change all these numbers, but the better they make them for towing in OD, the worse they make them for running empty, which I also do a lot of.
The real issue here is the gear spread from the top OD gear to direct and the lack of torquey engines.
On the 6R140 the ratios are 0.67, 0.86 and 1.15. The 68RFE has even better ratios. All the rest of the transmissions out there have a big gap between OD and direct.
And no stock engine is making 1000+ ftlbs.
The right engine coupled with the right transmission will make towing these big trailers very easy.
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Yeah that is what i have been working through. I'm still rocking the 7.3 for now. I have been looking for some 05+ dually 4.10 axles. Especially since Alcoa makes some classic series wheels for those axles now! I usually average 10 mpg out of mine but have seen low as 6 in bad head winds. looks like you will still be under the HP range that starts cooking drive line components. I have towed at the 400rwhp range and could not keep the drive line happy.
Sent from my DROID RAZR using Tapatalk 2
Sent from my DROID RAZR using Tapatalk 2
Here is how towing works with the 6.4/5R110. I suspect it would be worse with a 6.0L.
Here is the power curve for a 6.4L engine.
The 5R110 ratios are 0.71:1, 1:1 and 1.54:1
On a flat highway with no headwind, my F350 pulls my trailer quite nicely in OD. No complaints there. The engine purrs along, everything is quiet and smooth.
Engine speed at 60 MPH in OD, with 20s is 605 revs/mile x 3.73 x 0.71 = 1600 RPM. At 64 MPH its 1709 RPM.
Peak torque on the 6.4L is 650 ftlbs, but that is at 2000 RPM. At 1600-1700 RPM its making about 550 ftlbs.
1600 RPM x 550 ftlbs / 5252 = 167 HP.
1700 RPM x 575 ftlbs / 5252 = 186 HP.
So it takes way less than 200 HP to pull my trailer at 60+ MPH in good conditions. And that is assuming that the transmission and engine controller allow the engine to max out its power before downshifting. I'm not so sure that is the case.
FWIW, my new trailer is a lot more aerodynamic than my old one was. I suspect that on flat ground the two needed about the same power.
Things start to get interesting when you add hills and/or headwinds. At some point the transmission and engine decide its time for a downshift and it does take much of either to make it happen, especially when its a hill.
When I say hills, I am not talking about mountain passes. I am talking about hills in otherwise flat country. Hills on a secondary 2 lane highway where there is no passing lane. Those sorts of hills.
Engine RPM in direct at 60 MPH with 20s is 605 x 3.73 = 2250, which is not the end of the world. At 64 MPH, its 2400 RPM, which is liveable if its not all the time.
At 2250, the engine is making 2250 x 640 / 5252 = 274 HP.
At 2400, the engine is making 2400 x 630 / 5252 = 287 HP.
This is assuming that the engine and transmission controller allow the engine to make full torque.
Once again, this is all pretty much OK, provided that the truck doesn't need to run in direct pretty much all the time, which sometimes happens in a strong headwinds and hilly country. Then life is a continuous series of downshifts to get up to speed and downshifts when the truck can't maintain the load in OD.
The real problem happens when the truck decides it needs more power and downshifts into 3rd.
Engine speed at 60 MPH is 605 x 3.73 x 1.54 = 3475 RPM. Actually its more like 31-3200 RPM, for various reasons I won't get into.
The engine is making about 330 HP here, only about 40 HP more than it was in direct. But now its turning 50% more RPM.
So there you sit, engine screaming away going up the hill. Sooner or later the cooling fan kicks in and now you are down to 20 HP more than you had in direct at 2400.
As far as I know there is no way to lock the 5R110 out of shifting into 3rd gear. As a matter of fact, the shift happens sooner if you are using Tow Haul mode.
The only way to control the transmission is to turn off cruise control, if you were using it, and manually feather the throttle to keep the transmission in direct instead of 3rd. That means running it at about 75% of full power, which is about 275 x 75% = 206 HP. Which is only 20 HP more than we had in OD ! And by this time you are down to about 45-50 MPH. If you are on a 2 lane road and there is traffic behind you, they are not happy. The only other choice is to floor it and allow it to downshift back into 3rd and scream away.
I find this all EXTREMELY frustrating.
There are other issues too, like the downshift points when engine braking is needed and how the TC never seems to be locked when accelerating, but I'll leave them out for now.
Stock for stock, the 6R140 is 3 times the transmission the 5R110 is because a) its got more/better ratios, b) its stronger, c) its got a much better TC, that allows way more engine lugging and d) it allows 2 modes of manual control in addition to better automatic control.
The more I write the more frustrated I am that I don't have my swap done. I'll be towing our trailer about 3,000 miles over several mountain ranges in August.
I'm writing all this from a vet's office. Our dog somehow got sick during our travels.
Here is the power curve for a 6.4L engine.
The 5R110 ratios are 0.71:1, 1:1 and 1.54:1
On a flat highway with no headwind, my F350 pulls my trailer quite nicely in OD. No complaints there. The engine purrs along, everything is quiet and smooth.
Engine speed at 60 MPH in OD, with 20s is 605 revs/mile x 3.73 x 0.71 = 1600 RPM. At 64 MPH its 1709 RPM.
Peak torque on the 6.4L is 650 ftlbs, but that is at 2000 RPM. At 1600-1700 RPM its making about 550 ftlbs.
1600 RPM x 550 ftlbs / 5252 = 167 HP.
1700 RPM x 575 ftlbs / 5252 = 186 HP.
So it takes way less than 200 HP to pull my trailer at 60+ MPH in good conditions. And that is assuming that the transmission and engine controller allow the engine to max out its power before downshifting. I'm not so sure that is the case.
FWIW, my new trailer is a lot more aerodynamic than my old one was. I suspect that on flat ground the two needed about the same power.
Things start to get interesting when you add hills and/or headwinds. At some point the transmission and engine decide its time for a downshift and it does take much of either to make it happen, especially when its a hill.
When I say hills, I am not talking about mountain passes. I am talking about hills in otherwise flat country. Hills on a secondary 2 lane highway where there is no passing lane. Those sorts of hills.
Engine RPM in direct at 60 MPH with 20s is 605 x 3.73 = 2250, which is not the end of the world. At 64 MPH, its 2400 RPM, which is liveable if its not all the time.
At 2250, the engine is making 2250 x 640 / 5252 = 274 HP.
At 2400, the engine is making 2400 x 630 / 5252 = 287 HP.
This is assuming that the engine and transmission controller allow the engine to make full torque.
Once again, this is all pretty much OK, provided that the truck doesn't need to run in direct pretty much all the time, which sometimes happens in a strong headwinds and hilly country. Then life is a continuous series of downshifts to get up to speed and downshifts when the truck can't maintain the load in OD.
The real problem happens when the truck decides it needs more power and downshifts into 3rd.
Engine speed at 60 MPH is 605 x 3.73 x 1.54 = 3475 RPM. Actually its more like 31-3200 RPM, for various reasons I won't get into.
The engine is making about 330 HP here, only about 40 HP more than it was in direct. But now its turning 50% more RPM.
So there you sit, engine screaming away going up the hill. Sooner or later the cooling fan kicks in and now you are down to 20 HP more than you had in direct at 2400.
As far as I know there is no way to lock the 5R110 out of shifting into 3rd gear. As a matter of fact, the shift happens sooner if you are using Tow Haul mode.
The only way to control the transmission is to turn off cruise control, if you were using it, and manually feather the throttle to keep the transmission in direct instead of 3rd. That means running it at about 75% of full power, which is about 275 x 75% = 206 HP. Which is only 20 HP more than we had in OD ! And by this time you are down to about 45-50 MPH. If you are on a 2 lane road and there is traffic behind you, they are not happy. The only other choice is to floor it and allow it to downshift back into 3rd and scream away.
I find this all EXTREMELY frustrating.
There are other issues too, like the downshift points when engine braking is needed and how the TC never seems to be locked when accelerating, but I'll leave them out for now.
Stock for stock, the 6R140 is 3 times the transmission the 5R110 is because a) its got more/better ratios, b) its stronger, c) its got a much better TC, that allows way more engine lugging and d) it allows 2 modes of manual control in addition to better automatic control.
The more I write the more frustrated I am that I don't have my swap done. I'll be towing our trailer about 3,000 miles over several mountain ranges in August.
I'm writing all this from a vet's office. Our dog somehow got sick during our travels.
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Here is how towing works with the 5.9 CR/ZF6 in my F250.
The ZF6 ratios are 0.73, 1.0 and 1.31 IIRC.
At 60 MPH the engine speed is 605 x 3.73 x 0.73 = 1650 RPM.
At 65 MPH, its 1784 RPM.
The 5.9CR is stock 610/325, except that I advanced the timing, so its probably making 630-650 ftlbs, all at 1600 RPM.
650 ftlbs x 1650 RPM/ 5252 = 204 HP. This is nearly 40 HP more than the 6.4 makes at the same truck speed, 60 MPH.
650 ftlbs x 1784/ 5252 = 220 HP. Again, 35 more HP than the 6.4 at the same speed.
My F250 pulled the trailer fairly nice in OD and could pull moderate hills without too much loss in speed. Being the ZF6 is a manual transmission, I could control when and if it downshifted. If there was no traffic behind me, I often let the engine pull down and torque its way up the hills.
On larger/longer grades, I'd have to downshift into direct. When I say grades, generally it would take a mile long climb at 3-5% before I'd need to downshift into direct.
Engine speed at 60 MPH in direct is 3.73 x 605 = 2250 RPM.
I don't have an engine curve for the 5.9CR, but it probably makes about 600 ftlbs here, so the engine power is 2250 x 600 / 5252 = 257 HP. This is about 20 HP less than the 6.4.
It takes a pretty good grade in both steepness and length to require a downshift from direct, especially if you let the speed fall back a bit, to say, 50-55 MPH. Being that the ZF6 is a manual transmission, you can do that.
Most mountain passes can be climbed at 50-55 MPH in direct. No fuss, no muss, its a bit slow, but if you are patient and enjoying the scenary, its a great way to go.
The next gear down is 3rd. Engine RPM at 60 MPH is 605 x 3.73 x 1.31, which is 2950 RPM.
This is pretty much wound out on a stock 5.9CR, but I usually let the speed drop to 50 MPH or so before downshifting into 3rd, so the RPM is more like 2450 RPM. The truck will pull a house up pretty steep inclines in this gear and I can only think of a time or two that I have ever shifted into second.
3rd gear is also a great downhill gear, as long as you keep the speed below about 65MPH. The 5.9CR provides pretty good engine braking even without an exhaust brake at this RPM and I can usually come down 5% grades without touching the brakes at all.
Fuel consumption wise, the 5.9CR uses about 25-40% less fuel than the 6.4, though the 5.9 might be slightly slower due to letting it pull down on hills.
However, the 6.4 is no speed deamon either if you are feathering the throttle in direct trying to keep it from screaming its brains out in 3rd gear.
So even though the 6.4L is rated at 650/350 I far prefer a 5.9CR with a ZF6 for heavy towing.
My apologies for boring people to death with this stuff. Our dog needs more tests.
The ZF6 ratios are 0.73, 1.0 and 1.31 IIRC.
At 60 MPH the engine speed is 605 x 3.73 x 0.73 = 1650 RPM.
At 65 MPH, its 1784 RPM.
The 5.9CR is stock 610/325, except that I advanced the timing, so its probably making 630-650 ftlbs, all at 1600 RPM.
650 ftlbs x 1650 RPM/ 5252 = 204 HP. This is nearly 40 HP more than the 6.4 makes at the same truck speed, 60 MPH.
650 ftlbs x 1784/ 5252 = 220 HP. Again, 35 more HP than the 6.4 at the same speed.
My F250 pulled the trailer fairly nice in OD and could pull moderate hills without too much loss in speed. Being the ZF6 is a manual transmission, I could control when and if it downshifted. If there was no traffic behind me, I often let the engine pull down and torque its way up the hills.
On larger/longer grades, I'd have to downshift into direct. When I say grades, generally it would take a mile long climb at 3-5% before I'd need to downshift into direct.
Engine speed at 60 MPH in direct is 3.73 x 605 = 2250 RPM.
I don't have an engine curve for the 5.9CR, but it probably makes about 600 ftlbs here, so the engine power is 2250 x 600 / 5252 = 257 HP. This is about 20 HP less than the 6.4.
It takes a pretty good grade in both steepness and length to require a downshift from direct, especially if you let the speed fall back a bit, to say, 50-55 MPH. Being that the ZF6 is a manual transmission, you can do that.
Most mountain passes can be climbed at 50-55 MPH in direct. No fuss, no muss, its a bit slow, but if you are patient and enjoying the scenary, its a great way to go.
The next gear down is 3rd. Engine RPM at 60 MPH is 605 x 3.73 x 1.31, which is 2950 RPM.
This is pretty much wound out on a stock 5.9CR, but I usually let the speed drop to 50 MPH or so before downshifting into 3rd, so the RPM is more like 2450 RPM. The truck will pull a house up pretty steep inclines in this gear and I can only think of a time or two that I have ever shifted into second.
3rd gear is also a great downhill gear, as long as you keep the speed below about 65MPH. The 5.9CR provides pretty good engine braking even without an exhaust brake at this RPM and I can usually come down 5% grades without touching the brakes at all.
Fuel consumption wise, the 5.9CR uses about 25-40% less fuel than the 6.4, though the 5.9 might be slightly slower due to letting it pull down on hills.
However, the 6.4 is no speed deamon either if you are feathering the throttle in direct trying to keep it from screaming its brains out in 3rd gear.
So even though the 6.4L is rated at 650/350 I far prefer a 5.9CR with a ZF6 for heavy towing.
My apologies for boring people to death with this stuff. Our dog needs more tests.
FWIW, I towed the same trailer with the same truck with both a 7.3 (235/500) and a 5.9CR (325/650ish) back to back.
A 5.9CR is a big improvement over a stock 7.3. The 5.9CR has quite a bit more grunt on the low end and makes a lot more power on the top end, especially in direct and 3rd gears, where the 7.3 seems to run out of breath.
Fuel wise, on a route where one isn't using the extra power the 5.9 has over the 7.3, the 5.9CR gets 10-20% better fuel economy than a 7.3. When using the extra power, it depends on how you are using it. If the engine speed is kept under control, the 5.9CR doesn't use any more. If you get hard on the throttle, it can use more.
A 5.9CR is a big improvement over a stock 7.3. The 5.9CR has quite a bit more grunt on the low end and makes a lot more power on the top end, especially in direct and 3rd gears, where the 7.3 seems to run out of breath.
Fuel wise, on a route where one isn't using the extra power the 5.9 has over the 7.3, the 5.9CR gets 10-20% better fuel economy than a 7.3. When using the extra power, it depends on how you are using it. If the engine speed is kept under control, the 5.9CR doesn't use any more. If you get hard on the throttle, it can use more.
Here is how I hope towing goes with the Cummins 6.7 and 6R140.
First off, at any speed more than about 20 MPH, I hope to have the TC on the 6R140 firmly locked except when the transmission is shifting.
One of the things that really bothers me about the 5R110 is that even in Tow Haul mode the TC doesn't seem to lock much until the truck is doing 45-50 MPH in at least direct, if not OD. Even when unloaded, slow acceleration requires 2000 RPM due to lots of TC slip. When towing, slow acceleration requires at least 2600 RPM and anything fast has the tach pegged.
This is in sharp comparison to the 5.9CR/ZF6 in my F250 where it seldom gets revved above 2,000 RPM when empty and manages to accelerate pretty well. Even when towing, it would seldom go above 2600 RPM.
Of course the 6R140 will be under full manual control if I want it to be.
The top 6R140 ratios are 0.67, 0.86 and 1.15.
Engine speed at 60 MPH in top OD is 605 x 3.73 x .67 = 1511 RPM. At 65 MPH, its 1640 RPM.
I'm hoping my engine will make at least 1000 ftlbs at 1600 RPM. I'm shooting for 1200 ftlbs.
1500 RPM x 800 ftlbs / 5252 = 228 HP. This is nearly as much power as a stock 7.3 makes.
1500 RPM x 1000 ftlbs / 5252 = 285 HP. This is as much power as the 6.4 makes in direct.
1600 RPM x 1000 ftlbs / 5252 =304 HP. This is as much power as the 5.9CR makes in 3rd gear at 2700 RPM.
1600 RPM x 1200 ftlbs / 5252 = 365 HP. This is more power than either the 5.9CR or the 6.4L make.
Theoretically, if my 6.7 makes 1200 ftlbs at 1600 RPM, it should be a tow beast even in double OD. Having said all that, I'm not sure that I'll let the engine make that much power/torque in that gear. If it made 800 ftlbs at 1600 RPM, that would be 240 HP, which would be more than enough for cruising on flat highways, which is probably all I want to use that gear for.
Having said all that, the Ford 6.7 is said to pull 5ers really well at 60-65 MPH in 2nd OD, even on trucks with the 3.31 axle ratio, though they do have somewhat smaller tires than the 20s on my truck.
The rating on the Cummins marine 6.7 said that wide open throttle (1165 ftlbs) was to be used less than 1 hour in 8. I don't want to make a habit of cruising down the highway at 15-1600 RPM with the engine at a really high torque load.
And that is OK with me, because...
The first shift down is 1st OD. Engine speed in that gear at 60 MPH is 605 x 3.73 x 0.86 = 1940 RPM. At 65 MPH its 2100 RPM. I think this is a beautiful gear ratio for towing.
Here I definitely want to be making 1200 ftlbs. The marine 6.7 makes 1165 ftlbs at 2,000 RPM.
1940 x 1200 / 5252 = 443 HP. That is 100 HP more than a 6.4 makes wound out in 3rd gear.
2100 x 1200 / 5252 = 480 HP. That is 100 HP more than the most powerful stock Duramax, more than twice what a stock 7.3 makes.
I should be able to climb some very steep and long grades at 60-65 MPH with this sort of power, stress free.
The engine is running at a perfect speed in this gear for good fuel economy. Its not lugging and its not over revving.
The next gear down in the 6R140 is "direct" with a ratio of 1.15.
Engine speed at 60 MPH is 3.73 x 605 x 1.15 = 2600 RPM. At 65 MPH, its 2811 RPM.
This will be my power pulling gear and I love the ratio. Its a faster ratio than 3rd in the 5R110 and 3rd in the ZF6. It will be perfect for engine braking down long descents, without fear of over revving.
2600 x 1000 ftlbs / 5252 = 495 HP.
2600 x 1200 ftlbs / 5252 = 594 HP.
2800 x 1000 ftlbs / 5252 =533 HP.
2800 x 1200 ftlbs /5252 = 640 HP.
I'll probably only use this gear and this sort of power for passing and climbing steep grades. I love the thought of doing long, steep climbs at 50 MPH (2166 RPM) in this gear to save fuel.
2166 RPM x 1200 ftlbs / 5252 = 495 HP, if I need it.
I hope everything works as well as I think it will. I can't wait to get it going.
Sorry for all the babble. It passed the time while I wait to find out what is wrong with our dog.
First off, at any speed more than about 20 MPH, I hope to have the TC on the 6R140 firmly locked except when the transmission is shifting.
One of the things that really bothers me about the 5R110 is that even in Tow Haul mode the TC doesn't seem to lock much until the truck is doing 45-50 MPH in at least direct, if not OD. Even when unloaded, slow acceleration requires 2000 RPM due to lots of TC slip. When towing, slow acceleration requires at least 2600 RPM and anything fast has the tach pegged.
This is in sharp comparison to the 5.9CR/ZF6 in my F250 where it seldom gets revved above 2,000 RPM when empty and manages to accelerate pretty well. Even when towing, it would seldom go above 2600 RPM.
Of course the 6R140 will be under full manual control if I want it to be.
The top 6R140 ratios are 0.67, 0.86 and 1.15.
Engine speed at 60 MPH in top OD is 605 x 3.73 x .67 = 1511 RPM. At 65 MPH, its 1640 RPM.
I'm hoping my engine will make at least 1000 ftlbs at 1600 RPM. I'm shooting for 1200 ftlbs.
1500 RPM x 800 ftlbs / 5252 = 228 HP. This is nearly as much power as a stock 7.3 makes.
1500 RPM x 1000 ftlbs / 5252 = 285 HP. This is as much power as the 6.4 makes in direct.
1600 RPM x 1000 ftlbs / 5252 =304 HP. This is as much power as the 5.9CR makes in 3rd gear at 2700 RPM.
1600 RPM x 1200 ftlbs / 5252 = 365 HP. This is more power than either the 5.9CR or the 6.4L make.
Theoretically, if my 6.7 makes 1200 ftlbs at 1600 RPM, it should be a tow beast even in double OD. Having said all that, I'm not sure that I'll let the engine make that much power/torque in that gear. If it made 800 ftlbs at 1600 RPM, that would be 240 HP, which would be more than enough for cruising on flat highways, which is probably all I want to use that gear for.
Having said all that, the Ford 6.7 is said to pull 5ers really well at 60-65 MPH in 2nd OD, even on trucks with the 3.31 axle ratio, though they do have somewhat smaller tires than the 20s on my truck.
The rating on the Cummins marine 6.7 said that wide open throttle (1165 ftlbs) was to be used less than 1 hour in 8. I don't want to make a habit of cruising down the highway at 15-1600 RPM with the engine at a really high torque load.
And that is OK with me, because...
The first shift down is 1st OD. Engine speed in that gear at 60 MPH is 605 x 3.73 x 0.86 = 1940 RPM. At 65 MPH its 2100 RPM. I think this is a beautiful gear ratio for towing.
Here I definitely want to be making 1200 ftlbs. The marine 6.7 makes 1165 ftlbs at 2,000 RPM.
1940 x 1200 / 5252 = 443 HP. That is 100 HP more than a 6.4 makes wound out in 3rd gear.
2100 x 1200 / 5252 = 480 HP. That is 100 HP more than the most powerful stock Duramax, more than twice what a stock 7.3 makes.
I should be able to climb some very steep and long grades at 60-65 MPH with this sort of power, stress free.
The engine is running at a perfect speed in this gear for good fuel economy. Its not lugging and its not over revving.
The next gear down in the 6R140 is "direct" with a ratio of 1.15.
Engine speed at 60 MPH is 3.73 x 605 x 1.15 = 2600 RPM. At 65 MPH, its 2811 RPM.
This will be my power pulling gear and I love the ratio. Its a faster ratio than 3rd in the 5R110 and 3rd in the ZF6. It will be perfect for engine braking down long descents, without fear of over revving.
2600 x 1000 ftlbs / 5252 = 495 HP.
2600 x 1200 ftlbs / 5252 = 594 HP.
2800 x 1000 ftlbs / 5252 =533 HP.
2800 x 1200 ftlbs /5252 = 640 HP.
I'll probably only use this gear and this sort of power for passing and climbing steep grades. I love the thought of doing long, steep climbs at 50 MPH (2166 RPM) in this gear to save fuel.
2166 RPM x 1200 ftlbs / 5252 = 495 HP, if I need it.
I hope everything works as well as I think it will. I can't wait to get it going.
Sorry for all the babble. It passed the time while I wait to find out what is wrong with our dog.
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Powerstroke Cowboy
Well-known member
You would be farther ahead putting a PDF delete exhaust, EGR delete, Intake, Better Intercooler and Elites Tow power on your 6.4 Along with good tunning... You would wonder why you ever even tried to keep it stock..
Your MPG might even go up by 4+ MPG... towing!! Even more empty...
Your MPG might even go up by 4+ MPG... towing!! Even more empty...
Thanks for the advice, PC.
I have no doubt that the 6.4 could be improved considerably with mods.
However, I have no interest in keeping it or the 5R110 in my truck.
Rightly or wrongly, I am fully commited to finishing my Cummins 6.7/6R140 swap.
I have no doubt that the 6.4 could be improved considerably with mods.
However, I have no interest in keeping it or the 5R110 in my truck.
Rightly or wrongly, I am fully commited to finishing my Cummins 6.7/6R140 swap.
Not swap related, but Bilstein 5160s installed on the rear. I'll put bellows on the them later.
There isn't a lot of extra room on the passenger side.
Hint. Use a 1" ratchet strap to compress the shock to the right length to fit the bolt holes. These shocks are WAY harder to compress than the stock shocks.
There isn't a lot of extra room on the passenger side.
Hint. Use a 1" ratchet strap to compress the shock to the right length to fit the bolt holes. These shocks are WAY harder to compress than the stock shocks.
My old truck (with air ride) has 5100s. They cannot be tuned.
My new truck has 5160s. They have stock tuning right now. I'll tune them for the air ride system if they need it after I install it.
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5160s on the front.
Its tight. There isn't much room to get the reservoir in a position where it isn't going to interfere with the spring, tire, brake line or hub. Its going to be very interesting when the spring gets replaced by an air bag. I suspect that the reservoir will need to be mounted to the frame then.
The 5160s come with a brake line relocation kit for earlier Ford trucks, where the brake line is fed aft of the shock. My '99 is like that. On my 08, the brake line comes from in front of the spring and no relocation is needed.
Its tight. There isn't much room to get the reservoir in a position where it isn't going to interfere with the spring, tire, brake line or hub. Its going to be very interesting when the spring gets replaced by an air bag. I suspect that the reservoir will need to be mounted to the frame then.
The 5160s come with a brake line relocation kit for earlier Ford trucks, where the brake line is fed aft of the shock. My '99 is like that. On my 08, the brake line comes from in front of the spring and no relocation is needed.
Why don't I just buy a Dodge truck and "be done with it" ?
I don't want to start a debate on this issue, just share some insight into why I am doing the swap rather than buying a Dodge truck.
Each to their own. I spent the weekend parked beside a 2012 Dodge 3500 Megacab dually. They are very nice. I can see why people like them.
Here are some weights from our setup, loaded, full of fuel, some water in the tanks, me and our dog in the cab.
Front axle 5,170 pounds
Rear axle 5,852 pounds
Truck Total 11,022 pounds
Trailer axles 11,176 pounds
Total combination weight 22,200 pounds.
This doesn't include a second trailer that we might pull behind the 5er.
1) Payload
The 2012 Ram trucks have a maximum GVWR of 10,100 pounds as a SRW and 10,500 pounds in a Mega Cab DRW.
The GVWR on my 08 F350 is 11,500 pounds and its SRW.
The pin weight on my 5er is about 2500 pounds, depending on how its loaded. Depending on how you define empty, my F350 weighs about 8200 pounds, leaving a payload of 3300 pounds.
Dodge advertises the SRW MegaCab as having a payload of 2530 pounds based on a 10,100 pound GVWR. That implies it has an empty weight of 7570 pounds, which I find hard to believe. If it does truly weigh that, my F350 has a lot more steel in it.
I'm not sure what the limiting factor is when it comes to the Dodge GVWR, but I find it troubling that it is so much lower than the Ford GVWRs.
Some people say that these are just numbers and they don't matter. If they don't really matter then I would like Dodge to put different numbers in their brochures and cab stickers.
In any event, I'd have payload issues using even a DRW MegaCab 3500 to pull my trailer.
2) GCWR
The highest GCWR available on a MegaCab with a 3.73 axle ratio is 21,000 pounds, leaving a maximum trailer tow weight of 12,950 pounds. Here they are saying the truck will weigh 8,000 pounds.
The maximum GCWR on a MegaCab DRW with the 4.10 axle ratio is 24,000 pounds.
The stock GCWR on my '99 F250 7.3 ZF6 3.73 was 20,000 pounds ! It weighed 7,000 pounds empty, leaving a trailer weight of 13,000 pounds.
The stock GCWR on my 08 F350 SRW 6.4 auto 3.73 with 20 inch tires is 23,500 pounds. Its rated to pull a 15K trailer.
The stock GCWR on a 2012 F350 SRW 6.7 auto is 23,500 pounds with the 3.31 and 3.55 axles and 30,000 pounds (!) with the 3.73s. You can't even get 3.73s without going to a dually in a 2012 Ford.
I am very happy my 08 has 3.73s. With a built Cummins 6.7 and the 6R140, it should be good, power wise anyway, for a GCWR of nearly 30K.
I do not want a dually if I can avoid it and I certainly don't want a 4.10 axle.
Again, I am not sure what the limiting factor is when it comes to the GCWRs of the Dodge trucks. It certainly isn't limited by the engine as the 6.7 is used in motorhomes with a GCWR of over 30,000 pounds as well as a rating of 30K in the regular cab LB DRW trucks with 4.10 axles.
3) Transmission Issues
I do not believe the 68 RFE is as strong as the 6R140. I do not believe the 68RFE would withstand towing my trailer with a built Cummins 6.7.
4) Box length
I really wanted a long box truck this time, for cargo capacity. You cannot get a Mega Cab with a long box.
5) Tires and Rims
I am very partial to 20 inch tires on SRW trucks. You cannot get them on a factory Dodge truck.
6) Cost
Dodge trucks sell at a premium to Ford trucks, similarly equipped. Furthermore, I don't care for the interiors on the pre 2010 Dodge trucks, so I would have been forced to find a used 2010+ Dodge 3500 MegaCab, which would have cost a lot more than my F350 did.
7) Towing Mirrors
I love the Ford 08+ towing mirrors, especially the power folding mirrors on my F350.
I'm not saying my F350 is a perfect truck. It just works better for me and my application than some other trucks do.
You should compare apples to apples. The crew cab Ram is still As big or bigger inside than. The SD crew cab and:
1 has a GVW of 12300 lb
2 has a GCVW of 29100 lb
3 The latest trans behind the Cummins seems to be holding up pretty well
4 the crew cab comes with an 8 ft bed
5 buy a set of 19.5s with real MDT tires
6 cost is relative. I purchased my Ram new at 12000 under the sticker and sold my 6.0 outright
7 I think the Ram flip up mirrors are easily as good as the SD mirrors
IMHO It would be a hell of a lot easier and in the long run cheaper to just go buy a 6.7 Ram delete the emissions throw on some 19.5s and tow away
