The Ultimate Tow Truck

[Macrobb]

The speed you are going to be going matters:
With a 5-speed manual, 4.10 gearing, you are going approximately 2050 RPM @ 60. 2550 @ 75 in top gear.
With 4.63 gearing, 2315 @ 60, 2880 @ 75 in top gear.

With an E4(uh-oh)D, 4.10 gearing you are going approximately 1912 RPM @ 60, 2390 @ 75 in top gear.
With 4.63 gearing, 2162 @ 60, 2702 @ 75 in top gear.

Now, with a turbo, that's still in the power band, at both places... though my canculations and personal feelings suggest that aiming for about 2400 RPM would be a better number aiming for in top gear.
Remember, you can always downshift if you need more power. If you have a 5-speed(or E4OD), and you can't be in Overdrive while towing heavy...So?
That's what it's there for: you plan on top gear being your cruising gear, with lower revs meaning better economy, and having the ability to downshift to get more power if needed.

Overall, with a 5 speed, 4.10 gearing makes sense. With a E4(uh-oh)D, you can probably go a bit higher numerically and still have a truck that isn't screaming at you.

Here's a great link showing all the gearing combinations:
https://www.gearvendors.com/fdrive.html
To calculate RPM( with stock tires), I'm using a number of final drive ratio of 3.12 = 2050 @ 60mph.

my rig will most likely never see a dyno.

Aw... I really want to see what you make!

most of the chassis dynos around here are ran by people I don't much care for.
so ill stick to my own little world lol

Nothing like the NWDC coming around your area? Public dyno events?

 

[no mufflers]

I do like manual transmissions but with the right programmer an E4OD would be far superior. I will admit stock for stock the ZF would be better. if you think about it, the E4OD locks up in 3rd and 4th gear so if you can split the gear or un lock the TC you could have a 6 speed.

 

[FORDF250HDXLT]

You left out the rpm info for double OD with 4.63 gears.While he's decided on the E4OD,there is no restriction to tow while in OD like the ZF5.So if the GV is really ok to use in double over as well,the F450 platform/E4OD/4.63 + crew cab swap would truly be the ultimate IDI towing machine for cruising 'Merica with.
(So long as it's not coming from my wallet lmao)

Edit,
Doug.I just saw you mention 4wd is a must but imho,I think you should rethink that one.4wd hurts economy to much for a country side tow hauler imho.Id go 2wd.
If your selling off the stang (may the classic car gods forgive you!) and keeping your newer truck.Just use that when you need 4wd......What do you need 4wd for in Texas though?

 

[burt]

I run 4:88s with a gearvendor and it is sweet on a turbo 7.3. Unbiased opinion would be to put a 12v cummins in this rig rather than an idi tho. The combo of an obs ford with a 12v is better in every way that I know of. I love idi but idk how anyone could argue it against a cummins. If you are going 4x4 I'd say d60 front for sure

 

[FORDF250HDXLT]

I run 4:88s with a gearvendor and it is sweet on a turbo 7.3. Unbiased opinion would be to put a 12v cummins in this rig rather than an idi tho. The combo of an obs ford with a 12v is better in every way that I know of. I love idi but idk how anyone could argue it against a cummins. If you are going 4x4 I'd say d60 front for sure

Ah.So the ultimate platform and build continues and goes as;

1992-1997 F-super Duty/F-450.
Cummins swap with built E4OD/4R100
Crew cab swap.
1999+ Front & rear F450/F550 axles.-Whatever truck and year of the Dana super 60! Along with the rear axle (iirc 4.88 as well)
Now you have super hd front and rear with 4 wheel disc w/ebrake (a proper f450 4wd conversion imo).
GV overdrive unit for double over
Need a divorced t-case then I guess?

There's your ultimate 4wd,towing machine.
With the awesome gearing and GV,the IDI would be just fine though (save for the Rockies! lol)
Now all you need,are several thousand in both hours and money to buy and build it.

I'd still rather keep that stang!

 

[burt]

Is that super 60 a unit bearing metric axle like the super duties have? If so I'd rather stay with serviceable bearings. if you are going to be running a turbo I think putting a cummins in is easier than putting an idi in. Everything is easier with an inline 6. There is some Money in adapters and whatnot but not too bad if you are shooting for ultimate. 4:88 is a little low for a cummins even with the gv but highly recommend it on an idi.

 

[Macrobb]

Personally, I think of Cummins engines as the gold standard: Nice, simple, efficient and way too expensive to own.

I've picked up two whole turbo-IDI-powered OBS trucks for under $2k. I've also seen people selling 12V Cummins *engines* for over 2K by itself!

For the price of buying a cummins and swapping it in, I can easily build an IDI to have as much if not more power. IDIs are just plain cheap motors to find, work on, and maintain.

 

[burt]

The thread is ultimate tow truck. He said he's ready to spend some money on it. It is way harder and more expensive to get power out of an idi. I love idi and have put lots of money into them but after going Fummins it's hard to go back

 

[towcat]

The thread is ultimate tow truck. He said he's ready to spend some money on it. It is way harder and more expensive to get power out of an idi. I love idi and have put lots of money into them but after going Fummins it's hard to go back

i've driven both. with weights GROSSiING in the 17k-21k/lbs range.
before you throw the BS flag, this is very legal with a F450 type truck. the Cummins is a much more capable motor in sheer pulling power, but you will be constantly shifting to stay in the power band. whereas the V8 IDI has a wider powerband and is much more forgiving on how far you ride the throttle between shifts. Rearend gearing also changes the V8 IDI. those of you who have rode in my F450 carriers have had firsthand experience what a non-turbo'd truck can do and it's nothing short of impressive. yes, it falls on it's face in the hills, but so does a IH 4700 with the highly vaunted DT466E. what's the difference between the F350 and F450? rear end gearing. 4.10 in the 350 and a choice of 4.63 or 5.13 in the 450. yes, there is a cost on the top end of a 450, you are restricted to 75mph when loaded to 15k/lbs legal. with a f350, a 4.56 geared truck with turbo and IC does not need to exotic. a fairly stock build with a warmed up IP is all you really need. your goal is to make reasonable horsepower that won't burn up your motor going up steep grades when pulling a trailer. dyno queens with their stupid hp numbers are not an accurate reflection of what you need in reality. my F450 carrier drove more than a million miles in 20 years all over the lower 48 ( I did stay out of the northeast corner of the US though) and has left me needing a tow three times. being non-turbo makes roadside repairs easy to do. DOT has verified my logbooks to 980k/mi and I don't have many regrets on the way I got the truck from Ford.

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for the morbidly curious, that's the truck and the old lady back in 1996. here's a more recent pic of the truck. yes, I take care of my equipment.

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[FordGuy100]

I didn't know you had long hair Calvin

 

[Macrobb]

your goal is to make reasonable horsepower that won't burn up your motor going up steep grades when pulling a trailer. dyno queens with their stupid hp numbers are not an accurate reflection of what you need in reality.

Eh... Once you drive your first high-HP IDI, you'll never go back. Keep an eye on EGT numbers and you can haul all day long. Also, near as I've been able to tell, EGTs get out of control only when you have too much fuel for your air. You don't lose much power by backing off enough to keep the EGTs in the safe range.

My older truck, an 88, verified at making 248 at the wheels. I've hauled heavy with it quite a few times, including a nice trip grossing probably ~20.5K(14K trailer + 6.5K truck), up a nice long grade for minutes on end.

When I pulled the heads off that motor a few months later, the pistons had no issues whatsoever.
(Note, though, that when your machine shop doesn't spec the valves to the right recession, bad things happen to valve guides).

So I'm totally convinced that it's possible to have a high-HP, heavy-hauling IDI that will last quite a long time, if you build it correctly.

 

[towcat]

Eh... Once you drive your first high-HP IDI, you'll never go back. Keep an eye on EGT numbers and you can haul all day long. Also, near as I've been able to tell, EGTs get out of control only when you have too much fuel for your air. You don't lose much power by backing off enough to keep the EGTs in the safe range.

My older truck, an 88, verified at making 248 at the wheels. I've hauled heavy with it quite a few times, including a nice trip grossing probably ~20.5K(14K trailer + 6.5K truck), up a nice long grade for minutes on end.

When I pulled the heads off that motor a few months later, the pistons had no issues whatsoever.
(Note, though, that when your machine shop doesn't spec the valves to the right recession, bad things happen to valve guides).

So I'm totally convinced that it's possible to have a high-HP, heavy-hauling IDI that will last quite a long time, if you build it correctly.

when I am on a long drive "FOR FUN" it is no fun whatsoever when you superglue an eyeball to the pyro every time you fire up the damn rig. besides, those who are qualified to "borrow" my rig, aren't held responsible for not using superglue either. they know if they break it, it gets fixed or replaced.

 

[D_Fresh361]

Ah.So the ultimate platform and build continues and goes as;

1992-1997 F-super Duty/F-450.
Cummins swap with built E4OD/4R100
Crew cab swap.
1999+ Front & rear F450/F550 axles.-Whatever truck and year of the Dana super 60! Along with the rear axle (iirc 4.88 as well)
Now you have super hd front and rear with 4 wheel disc w/ebrake (a proper f450 4wd conversion imo).
GV overdrive unit for double over
Need a divorced t-case then I guess?

There's your ultimate 4wd,towing machine.
With the awesome gearing and GV,the IDI would be just fine though (save for the Rockies! lol)
Now all you need,are several thousand in both hours and money to buy and build it.

I'd still rather keep that stang!

We drove from Victoria, TX to Spokane, WA end of June 2016 to visit family. Went up through Colorado, hit the Grand Tetons and ALL of Yellowstone National Park after that. When we came back from WA we drove East and saw Mount Rushmore. It was my first time traveling to the Northwest. There is absolutely no doubt that is gods country! Some of the most beautiful and breath taking views I've ever seen! I could definitely see how the Rockies would put a hurtin on the pocket book in an IDI pulling a load in them mountains!

After some more brain storming and consideration I have agreed that 4x4 is not the way to go with this rig. I am settled on 2wd. I will do the D60 swap on my 86 with the zf5.

 

[IDIoit]

Aw... I really want to see what you make!

Nothing like the NWDC coming around your area? Public dyno events?

the events I go to are filled with pre 64 hotrods and customs.
my life is so busy that I barley have time to go anywhere.

as far as dynoing my rig, im not really concerned with the power I don't make lol
the next time I have an engine dyno'd I most likely wont be there when the Butler crew builds me a engine for my flatbottom.
indian adventures II with tiger heads
i do love these IDI's, but when you call them "high HP" engines, it makes me think of a buddy who dropped 12k on a merc flathead v-8 and made 400 hp.
these engines are impossible by design to get any real power out of. they are the 8BA's

 

[D_Fresh361]

The speed you are going to be going matters:
With a 5-speed manual, 4.10 gearing, you are going approximately 2050 RPM @ 60. 2550 @ 75 in top gear.
With 4.63 gearing, 2315 @ 60, 2880 @ 75 in top gear.

With an E4(uh-oh)D, 4.10 gearing you are going approximately 1912 RPM @ 60, 2390 @ 75 in top gear.
With 4.63 gearing, 2162 @ 60, 2702 @ 75 in top gear.

Now, with a turbo, that's still in the power band, at both places... though my canculations and personal feelings suggest that aiming for about 2400 RPM would be a better number aiming for in top gear.
Remember, you can always downshift if you need more power. If you have a 5-speed(or E4OD), and you can't be in Overdrive while towing heavy...So?
That's what it's there for: you plan on top gear being your cruising gear, with lower revs meaning better economy, and having the ability to downshift to get more power if needed.

Overall, with a 5 speed, 4.10 gearing makes sense. With a E4(uh-oh)D, you can probably go a bit higher numerically and still have a truck that isn't screaming at you.

Here's a great link showing all the gearing combinations:
https://www.gearvendors.com/fdrive.html
To calculate RPM( with stock tires), I'm using a number of final drive ratio of 3.12 = 2050 @ 60mph.




Aw... I really want to see what you make!

Nothing like the NWDC coming around your area? Public dyno events?

I'm really digging those RPM numbers with the E40D and 4.10's at 75mph!

Thanks for the reference!