Building the ultimate towing truck.

[Hohn]

Justin,

I've towed heavy 5vers with both (47RE and NV5600). The gaps between gears are way too wide in the 47RE. With the automatic, I always found myself either running bunches of revs in a lower gear or unable to hold speed in the next higher gear.

It's much nicer having 6 more closely-spaced ratios to work with between 0 and 70 MPH.

The 6-speed Aisin automatic may just cure this problem and make me a slushbox convert on the next truck!

Rusty

Rusty, was this on your previous V-10 truck? I ask because the superior power of the CTD may offset the absence of ideal gearing, esp. wrt gear splits...

Also, would it make a difference if it was a 4. 10 axle vs. a shorter axle? Without crunching the numbers, it would appears that the axle ratio only affects VEHICLE SPEED, and has no effect on the INTERVAL between gears...

Let me know.

 

[Turbo Thom]

As soon as you started with your parameters you lost out. Single wheel won't get for the ultimate towing truck. Stay away from the twins. Why so you need um? 35" tires? Silly for towing. You're playing, not towing. When you're really serious, come back and talk towing. But in the meantime, have fun playing.



. . Preston. .

 

[Hohn]

Chris, clearly what we need to do in "building the ultimate tow rig" is first answer the question of "for towing what?"-- right?

I mean, the "ultimate tow rig" for a 2K bike trailer is probably quite different than it would be for a 35K G/N or a massive 36' 5er, right? In one case, you may want a 4. 56 axle-- in another, the 3. 73s would be plenty.

I know for a fact that the local Dodge Dealer in Cheyenne orders all their duallies with 3. 73s, not 4. 10s. Why? "because people don't like the high rpm at interstate speeds". In WY, "interstate speeds"= 80+mph. Yes people tow that fast. Yes, they die-- but that's another rant

 

[RustyJC]

Rusty, was this on your previous V-10 truck? I ask because the superior power of the CTD may offset the absence of ideal gearing, esp. wrt gear splits...

The V-10 was rated 300 BHP/450 lb-ft back in 1996. What was the stock 12 valve rated at back then?



The problem was that the V-10 reached peak torque at 2800 RPM, so with 3. 54 gears and towing in 3rd at about 2200 RPM or so at 65 mph, speed would drop when I hit a hill since I was on the front side of the torque curve (RPM drops, torque drops and HP falls like a rock!) Therefore, I wound up in 2nd gear, 3500 RPM and 55 mph. As we both know, HP determines how fast a given load gets up the hill, and the V-10 had a HP advantage over a stock 12 valve back in 1996 if I wanted to wind it up close to the 4000 RPM horsepower peak :{ . The earlier torque peak of the 12 valve may have altered its behavior since, in 3rd at 2200 RPM, it would be on the back side of the torque curve and could take advantage of torque rise (i. e. , its torque would increase as RPM dropped), but the point still stands - the split between 2nd and 3rd is too wide for heavy towing.

Also, would it make a difference if it was a 4. 10 axle vs. a shorter axle? Without crunching the numbers, it would appears that the axle ratio only affects VEHICLE SPEED, and has no effect on the INTERVAL between gears... .

When towing heavy at 65 to 70 MPH, with 4. 10s I can effectively use all 6 gears, even up hills (2350 RPM @ 70 MPH in 6th). With 3. 54s, I really would only have 5 useful gears (1st through 5th) since the 3. 54s run 2000 RPM @ 70 MPH in 6th). So, gear spacing doesn't change with axle ratio, but the useful road speed range of each gear does.



Rusty

 

[Blue Thunder]

As soon as you started with your parameters you lost out. Single wheel won't get for the ultimate towing truck. Stay away from the twins. Why so you need um? 35" tires? Silly for towing. You're playing, not towing. When you're really serious, come back and talk towing. But in the meantime, have fun playing.



. . Preston. .

I don't call dragging a 39 foot toy hauler over the GrapeVine or Donner Pass, 'playing', but to each, his own.



You're right I suppose, with-in those parameters what I'm building is not going to be the absolute 'ultimate' towing rig.



For that I would have a freakin big rig with 20 gears. For that matter, "the ultimate towing rig' wouldn't even have our puny (by comparison) 5. 9 CTD in it.



So, if you wish, we can say that we are building 'MY' ultimate towing rig. with these parameters.



Thanks, everyone else with offering your advice/experience. It is very helpful to be able to draw from this pool of knowledge in order to make expensive decisions on a future project.



Whether we are 'playing' or towing, we all are having fun.

 

[Idaho CTD]

What products would you suggest to build the ultimate towing ram?



Parameters: I would have to have the truck based on a 3500 SRW crew cab or MegaCab 4WD. I will lift it 2-4in. with 35's. 6-Speed, Gauges and E-Brake are a given.



1. Intake, turbo(twins?), intercooler.

2. Propane?, Snow?, Nitrous? Or none.

3. Fuel pump?

4. Fueling/timing boxes, Injectors.

5. Clutch?

6. Exaust.

7. Drivetrain.

8. 06 or EPA 07. 5?????



Opinions/Experience welcome.

This sounds a lot like my truck actually except the lift part. I have a auto in mine though. While a 6spd is nice for towing it's not as nice as a built auto for every day driving. Most of your towing sounds like it will be on the freeway/highway which means 5th and 6th gear in the standard or 3rd and OD in a auto. The gearing is almost the same in those two gears between the two transmissions. The upside to the auto is you could race it if you want to. With my truck I can run full tilt towing with the TST on 1-1 and BDDL on the 90hp setting and never go over 1150*. This combo dyno's about 420hp. ECT's stay in check too.



This is what I have on my truck:

1. Twins-stock turbo over a B2

2. Don M Helix 2 cam

3. Head studs

4. DTT full billet transmission

5. TST twins program

6. Bullydog downloader

7. Rasp mechanical lift pump



The upside is it runs high 12's to low 13's in the quarter mile too :-laf

 

[Turbo Thom]

Then if that's the case, your dangerous and need to stay off the road to start with. A 39' toy hauler has a 1 ton truck overloaded to start with, even with 4 rear wheels. Much less a single rear wheel. Now you're talking about lifting the truck for 35" wheels to tow that? I'm glad you live where you do and not around me. :{ I would hate to be even close to you when you get out of control. What you're talking about doing is not wise at all.



. . Preston. .

 

[Beast2B]

Boy, you sure get all kinds of helpful info!

The only thing I would address, from personal experience, is wheel/tire combination. With a 35-12. 50 tire, you'll want to use a wheel that is at or near the max recommended width for the tire. It will allow the tire tread contact patch to remain flat on the asphalt through a larger range of pressures. I run 37-12. 50 BFG on 8" wheels to keep them under the truck, but I get a good amount of tire sidewall sway and I have to monitor the tire pressure pretty closely.

As far as safe towing, drive smart and monitor tires/brakes/fluids. DUH!! Some people are so engrossed in GVW, GCW, etc that they forget to account for the driver...

 

[Blue Thunder]

Then if that's the case, your dangerous and need to stay off the road to start with. A 39' toy hauler has a 1 ton truck overloaded to start with, even with 4 rear wheels. Much less a single rear wheel. Now you're talking about lifting the truck for 35" wheels to tow that? I'm glad you live where you do and not around me. :{ I would hate to be even close to you when you get out of control. What you're talking about doing is not wise at all.



. . Preston. .

I'll keep that in mind.

 

[Silver600]

Then if that's the case, your dangerous and need to stay off the road to start with. A 39' toy hauler has a 1 ton truck overloaded to start with, even with 4 rear wheels.

. . Preston. .

You may want to re-do your math on that one. I tow one of the heavier 39 foot toy haulers available and it will be fine behind a dually. My 38ck (which is really 39 feet) has my SRW overloaded by 850 pounds with 120 gallons of water onboard so I ordered a dually. If I had more than my two lightweight quads (350 lbs each) in the back and carried less water it would lighten the pin and reduce the amount by which my rear axle is overloaded. If it were loaded correctly with enough weight behind the axles it wouldn't even overload a SRW. My new dually will be no where near overloaded.

 

[Turbo Thom]

600... ... What in the world are you taking about? What does the trailer weigh? Not what is your pin weight.

 

[dclassens]

By the way the start of this post sounds, cost is not as important as beating you friend . If you want to build the ultimate tow rig, and have some time, read the posts in this forum.



http://www.tdr1.com/forums/showthread.php?t=146113



Autoworld did a fantastic job!!

 

[rivercat]

I say for the "ultimate towing only truck" skip single wheel and dually and go for the full blown western hauler#ad



are C7 cats easy to mod?

 

[Idaho CTD]

You might also consider 19. 5" wheels and tires. I'm pretty sure you can get 35" and they have huge weight ratings. The down side is they dont have overly aggresive tread designs if that is something your looking for.

 

[Silver600]

600... ... What in the world are you taking about? What does the trailer weigh? Not what is your pin weight.

My trailer weighs 15500 loaded (17000 GVWR) but that is irrelevant. GVWR, GAWR and the capacity of the tires are the only numbers that are legally enforceable because they are the only numbers that are printed in your door (or the tires). The GCWR that Dodge advertises is not printed anywhere in your truck and varies based on which transmission and/or rearend you chose so it is not an enforceable number. Given that, as long as the pin weight of the trailer doesn't load my truck past its GVWR, GAWR or the rating of the tires it is not too much for my truck.

Then if that's the case, your dangerous and need to stay off the road to start with. A 39' toy hauler has a 1 ton truck overloaded to start with, even with 4 rear wheels. Much less a single rear wheel. Now you're talking about lifting the truck for 35" wheels to tow that? I'm glad you live where you do and not around me. I would hate to be even close to you when you get out of control. What you're talking about doing is not wise at all.



. . Preston. .

You act like this guy is going to kill someone by hooking a 39 foot toyhauler to his truck. I used my personal experience with a trailer this size to disprove that. My SRW truck has never been anywhere near out of control with this trailer. Yes, I admit my SRW is overloaded a little but like I stated in my last post it would be possible to tow it with a SRW and not be overloaded by adding more weight behind the axles and carrying less water. This trailer will not overload a dually. I looked at tires for my SRW and found E rated 35's that have a load rating higher than my stock tires.



I don't usually engage in arguments but I am still trying to figure out why you say a 39 foot toyhauler will overload a 3500 DRW and what the dangerous part of his combo is.

 

[Beast2B]

Silver600, excellent post. I recently sat down with a commercial CHP officer and asked questions like these relating to RV recreational use. He prioritized it like this:

1) tire capacity

2) axle capacities



Two caveats to this.

First, if you are driving like a moron (or look to be less than 100% in control), they will pull you over and be all over you to help you understand how critical it is to be safe.

Secondly, your liability is in your own hands if you exceed the specs as presented by the vehicle manufacturer, tire manufacturer, trailer manufacturer, hitch manufacturer (and anyone else the attorney's can get their teeth attached to!)

 

[BradyWilliams]

All good information but I see things this way.



#1 Super Phat Shaft 62/80, One turbo is less trouble than two.

#2 Pac Brake They make a brake that mounts on the turbo.

#3 TST/CR, Plenty of power without going too much.

#4 Snow Water/Meth Stage 2 or 3, For a little extra power, even more extra cooling

#5 AFE Stage II, To let the SPS 62/80 have all the air it needs.

#6 4" Stainless exhaust single or duals. New trucks already have a good sized exhaust.

#7 Pioneer N2 DVD/Navigation/Extra Gauges/Backup camera/XM radio/Stereo/Surround

#8 Fass 150 with a Racor 2 micron filter/clear bowl and a electric fuel heater 100 watt.

This will give you very nice hp with out over doing it. This will also have low EGT's and will allow you to drive as fast as you want to. The Snow Water /Meth is used for blowing over steep summits with out any worry or drop in mph.

It's tried and true! Thanks, Brady