Alexis700
tomboy
Tork tek OFV is always a good buy for a p7100 rig.
Adjustable too which is nice dial in FP where you want it.
Adjustable too which is nice dial in FP where you want it.
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Last Call Guest on these Group Buy Deal Items from Baja Designs
Anyone regret doing a Cummins swap?
- Thread starter YotaAtieToo
- Start date
YotaAtieToo
Thick skull
- Thread starter
- #1,082
I ordered one just cause, I figured the stretched spring will probably relax over time. Its not as easy to get to, so I figured I'll throw the tork in and be done.
I was also curious where I was at on boost. Looks like ~30 is the max I can get, I thought maybe the WG was opening, but iirc, the plug I got bypasses it unless I pull the bottom o ring. So my guess is I'm just not fueling enough for more.
YotaAtieToo
Thick skull
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- #1,083
Left town for Moab Sunday with the samurai in our 7x14 enclosed behind our F150. It's always done well towing rigs on open trailers and even my sister in laws 40' jayco, but for some reason it hates this enclosed. 60mph 4th gear and was saying 7mpg 
Turned around after 10 miles and swapped over to the fummings. 1k miles later here we are.....
Turned around after 10 miles and swapped over to the fummings. 1k miles later here we are.....
350TacoZilla
Well-known member
Sometimes aerodynamics matter more than weight and I'm guessing the F-150 sit low enough it just doesn't punch a big enough hole in the air.
YotaAtieToo
Thick skull
- Thread starter
- #1,085
I'd like to say there's no way a 4" different roof height would make that much difference, but idk. The F150 towed the cummins donor on a deck over like 300 miles and it did way better than this dumb enclosed. Maybe the shell messes with aero?
Cummins did about 12mpg at 65ish
arse_sidewards
Well-known member
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- May 19, 2020
- Messages
- 10,755
The lifted brodozer has **** aero to begin with so you don't notice when you hook a trailer with **** aero to it whereas you absolutely do notice the extra 70hp of load that the **** aero of the trailer puts on a vehicle that's starting from a position of half decent aerodynamics.
Tiha
Red Skull
Airflow wants to drop down after passing over the cab.I'd like to say there's no way a 4" different roof height would make that much difference, but idk. The F150 towed the cummins donor on a deck over like 300 miles and it did way better than this dumb enclosed. Maybe the shell messes with aero?
Cummins did about 12mpg at 65ish
A topper would help your pictured scenario.
Enclosed trailers are a brick wall.
YotaAtieToo
Thick skull
- Thread starter
- #1,088
F150 has a shell, sits a few inches lower sure. Both trucks are stock. I'd bet the F150 pulls a ~5k rig on a car trailer as good or better than this truck. 80mph getting 11mpg last time we went to Utah.
That 4k lb enclosed just ****s with that truck. 4th gear at 60mph. There's even a big hill close to home you can hit the top at 60, let off and hit ~75 at the bottom. With the trailer, you have to give it gas to maintain 60
Figured if I was stuck doing ~65 the whole time, may as well get better mileage with the Cummings. Plus the tank let me buy $4.40-4.75/g Montana fuel instead of the $5.30/g Idaho/Utah fuel..
I have a 26 foot bumper pull V nose trailer that weighs about 4,000 pounds empty. 10K# loaded. It’s by far the worst pulling trailer I’ve ever dragged. I get as bad of fuel mileage pulling this ****ing thing
As I ever did pulling these ones.
Some trailers just SUCK!
As I ever did pulling these ones.
Some trailers just SUCK!
![[486]](https://data.irate4x4.com/avatars/m/0/94.jpg?1700178133){kind=avatar}
[486]
smell-o-vision
lol seeing those first two pictures I can now understand why you hate bumper pull trailers
that thing looks like a nightmare to get the weight in the right place on, almost where you'd see an excuse for that stupid setup with torsion axles 8' apart
that thing looks like a nightmare to get the weight in the right place on, almost where you'd see an excuse for that stupid setup with torsion axles 8' apart
YotaAtieToo
Thick skull
- Thread starter
- #1,091
Good to know, my father in law has an almost identical trailer I've wanted to try. I'll keep that in mind.
Is it that trailer, or just any big enclosed? Do the gooseneck enclosed seem any different?
Also, Fwiw, we're home. 2k miles and the truck didn't skip a beat. No cruise control is pretty brutal and really need to address steering before another long trip. Just is very vague.
V30crewcab
Well-known member
enclosed trailers in general seem to suck towing.
Just that trailer. It’s a leaf spring and I blame the V nose for being the reason it pulls so horribly. I can’t find the pictures but I had a 38 foot cargo mate eliminator race trailer that weighed 7K empty. It was much more pleasant to pull weighing 17k~18K# loaded.
filthy_midget
Well-known member
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- Apr 25, 2024
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- 354
Thats odd, the v nose job trailers we have pull nicer even the high roof. Some trailers for whatever reason just pull good and some pull ****ty. You can take trailers off the exact same assembly line one after the other and they can pull different. Its ****ing weird and I dont fully understand it.
Same. Don’t understand the how. It’s just a box with wheels under it. Either all boxes should pull like ****, are all should pull just fine.
The annoying thing to me is that I custom ordered my V nose. I picked it up in Waco Texas and towed it home to Colorado. I hadn’t even made it out of Texas when I was looking at stuff on marketplace to put inside it so I didn’t have to go 1000 miles with it completely empty. I didn’t pick anything up but I thought about it.
YotaAtieToo
Thick skull
- Thread starter
- #1,097
Oh, no, that's not the case those were just the worst, followed shortly by the headlights
Mirrors and brakes are up there too.
Not sure if I'm going to dump money into it to make it work for long trips. But good to know I can grab it at a moments notice, check the oil and drive 2k miles without issue.
One thing that was nice, is it seems quieter in the cab, either the 12v is a little quieter and/or the sound deadening really helped.
350TacoZilla
Well-known member
My dads old flat nosed 7' interior cargo trailer pulled like a brick and you could see the front sheetmetal dimple in around the supports at about 60mph, his next one is 6' interior height so I knocked my head in it all the ****ing time and it pulled way better and front didn't dimple till about 72 or so, we usually would keep it under 65 with trailer but I pushed it to see when he first got it. Same trailer brand, same length, same truck etc.
YotaAtieToo
Thick skull
- Thread starter
- #1,099
Anyone have any input on ideal gearing/tire size/rpm for the 12v? I’m stuck in my room at work trying to adjust to night shift and figured id nerd out on it
There is conflicting info on what OD an nv4500 in a dodge has, but for practical comparison I’d say it’s close enough that guys with 2nd gen dodges are going to be really close. My ZF5 is 0.77. Also, my tach isn’t hooked up yet, and I can’t really remember what rpm was at what speed before
so just going off feel, 55 feels like where it really wants to easily cruise 60 isn’t bad, 65 is ok and 70 or more feels like its pushing it.
Currently 3.55s and 285s but they measure 15’’ hub to ground, speedo is dead on with gps.
Left is current, right is with 33.5” rolling radius tires (best guess on 35s)
8mph gain at the same rpm doesn’t seem right? I felt like my buddies who put 35s on their diesels all said it was about 5mph
Another option for conversation sake would be gear swap, id like to upgrade the brakes and the 05+ axle swap seems to make more and more sense than anything. 3.31s, and 3.73s are common enough.
3.31 left and 3.73 right with 35s
Wouldn’t be opposed to 37s either if it did make it tow like ass. Part of me feels like the Cummins likes tall gears and having a tall OD with direct gear having decent rpm might be nice and possibly more useable?
37s (36 rolling radius?) 3.55 left, 3.73 right
37s and 3.55s would be exactly the same as 3.31s and 35s apparently. 37s on tow rig is semi dumb, but the trips I have planned, it would be nice to do some mild trails in this and the long ass truck needs all the help it can get.
I’m sure it would be great having mega tall gears empty, just now sure how low is too low rpm wise for open highway towing? I don’t mind down shifting and slowing down for hills. But will it be happy at 1800 rpm and 75 with a decent trailer behind?
There is conflicting info on what OD an nv4500 in a dodge has, but for practical comparison I’d say it’s close enough that guys with 2nd gen dodges are going to be really close. My ZF5 is 0.77. Also, my tach isn’t hooked up yet, and I can’t really remember what rpm was at what speed before
so just going off feel, 55 feels like where it really wants to easily cruise 60 isn’t bad, 65 is ok and 70 or more feels like its pushing it.Currently 3.55s and 285s but they measure 15’’ hub to ground, speedo is dead on with gps.
Left is current, right is with 33.5” rolling radius tires (best guess on 35s)
8mph gain at the same rpm doesn’t seem right? I felt like my buddies who put 35s on their diesels all said it was about 5mph
Another option for conversation sake would be gear swap, id like to upgrade the brakes and the 05+ axle swap seems to make more and more sense than anything. 3.31s, and 3.73s are common enough.
3.31 left and 3.73 right with 35s
Wouldn’t be opposed to 37s either if it did make it tow like ass. Part of me feels like the Cummins likes tall gears and having a tall OD with direct gear having decent rpm might be nice and possibly more useable?
37s (36 rolling radius?) 3.55 left, 3.73 right
37s and 3.55s would be exactly the same as 3.31s and 35s apparently. 37s on tow rig is semi dumb, but the trips I have planned, it would be nice to do some mild trails in this and the long ass truck needs all the help it can get.
I’m sure it would be great having mega tall gears empty, just now sure how low is too low rpm wise for open highway towing? I don’t mind down shifting and slowing down for hills. But will it be happy at 1800 rpm and 75 with a decent trailer behind?
350TacoZilla
Well-known member
If you jump to a tire that is a true 35" tall it would almost be same as swapping to 3.08 with your current tires.
true 35" tall with 3.55=1813rpm@70 is what I get there and that sounds pretty decent to me.
Dropping speed from 70 to 60 is the exact same rpm drop. So if your current setup feel good at 60 then that's what a true 35 would be like @70 without factoring in the increased drag from the aero or the extra mass of the larger tires.
true 35" tall with 3.55=1813rpm@70 is what I get there and that sounds pretty decent to me.
Dropping speed from 70 to 60 is the exact same rpm drop. So if your current setup feel good at 60 then that's what a true 35 would be like @70 without factoring in the increased drag from the aero or the extra mass of the larger tires.
YotaAtieToo
Thick skull
- Thread starter
- #1,101
Probably have to go to a 37 to get a true 17.5" rolling radius. Even if the tire measures 35" it's still going to squish some. Measure hub to ground for speed calcs is what I was told.
My plan was 295/70r18 or 285/75r18, since I don't necessarily want 12.5 width. which supposedly measure just shy of 35" so I put 33.5" in the calculator as my best guess of actual rolling diameter
Yes, I agree. I still think gaining 10mph with 35s doesn't sound right. Now that I think of it my 4runner came with 265/70r16s (30.5) and with 35s the speedo is like 7mph off at 65. The F350 came with bigger tires, so I still say 10mph isn't happening.
Either way, I was just curious on peoples thoughts on rpm for this engine. I seem to remember Projectjunkie talking about his 12v loving low rpm, even towing.
Currently, I feel like I could use an entire extra gear. Like I feel like I could gear it where 4th is the same as the current 5th and it would be awesome, which would be 3.31s and 37s. But that just seems crazy.
Would probably be fine for a flat lander. Where you need to go? Not so sure
YotaAtieToo
Thick skull
- Thread starter
- #1,103
There are not many real grades between here and Utah or California. It's more just 80mph highways for long periods of time. But when I do hit grades, being so tall geared I have to hit 3rd gear, probably wouldn't be ideal
I don't think 3.31s and 37s is realistic, just kinda thinking out loud at this point. But I could do 37s now.....
Start with that and see if you go backwards on leverage.
YotaAtieToo
Thick skull
- Thread starter
- #1,105
I could, just would hate to spend the decent chunk of money for it not to work out.
Might have to just throw the ****ty 35s I have on and try it out before buying tires.
This is me mostly just sitting around with nothing to do but over think.....
Sounds like it 🤣.I could, just would hate to spend the decent chunk of money for it not to work out.
Might have to just throw the ****ty 35s I have on and try it out before buying tires.
This is me mostly just sitting around with nothing to do but over think.....
The numbers **** never works out in reality like it does on paper. Look at the hyper miler’s. They do all kinds of dumb **** to get rpm’s down and get better fuel mileage. The one thing that no one does, because it doesn’t work. Is taller tires. The friction loss is always far greater than the radius gain.
Nobody has ever gotten better fuel mileage by going to bigger tires. Anyone who thinks they did is lying to themselves. And it’s a super easy test. You just go back to the stock size. Get your acceleration AND your fuel mileage back.
Projectjunkie
Whatever
At 2800' towing my normal 8k load, my obs on 37s with ppump 12v nv4500 and 410s rarely used 1st and often reached for another over drive gear
4.10s and 285s on another 5 spd truck was gear bound
Hell, 355s on 2wd trucks with 265s feels gear bound
New build won't tow much, but it's 12v zf6 3.73s and 37s
That power train was headed for a cclb highway truck, think old man stuff, I wanted those 3.42s and metric 34.5s or whatever a 05 had
Then do tuning upgrades for clean power and reasonable egts
Lower rpms and more boost ftw...
Provience
Kill!
People will surely throw beer cans at me, but you don't actually have to cruise 80 on the freeway
V30crewcab
Well-known member
you do anywhere west of tx!People will surely throw beer cans at me, but you don't actually have to cruise 80 on the freeway
V30crewcab
Well-known member
I run 315/75/17 on my blue crew, 3.73, nv4500. it cruises 75-80 all day long, but might go to 4.10 for pulling excavator around. I'm around 24k loaded with the gooseneck and excavator on it. its a little hard getting started in 1st with that much weight.
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