02 GMC Yukon Towing Question

[aklim]

What is the most cost efffective way to tow that much? Cam? Supercharger? Gears?

[Hit Man X]

A mild cam on a tight LSA will help low speed torque, a bigger motor will (6.0 is most cost effective), a blower can for sure, gears also as you're more in the powerband...

[gearheadnate]

Originally posted by aklim@Oct 9 2005, 02:18 PM
My vehicle has 3.73 ratio for the rear end. 5300 Vortec with 3.73 rear end Since it is 4WD, I would rather not go to 4.10 since I have to change both gears. The book says the max capacity is 7500. However the 4.10 ratio one gets to tow 8500. Why the difference? Because the RPM is higher from the 4.10 gears?

Also The trailer dry weight will be 6000. Add about 1500# of ATVs and a few items and that should bring me to about 7500 and a couple more for other misc stuff. I would estimate that it shouldn't exceed 8000 . I will have a weight distribution hitch with the sway controller.

The good part is that I have Dynatech long tube headers, Transgo shift kit, larger transmission cooler and Billet Transmission servos and a Granatelli Intake. Also I have got Jesse to take out all torque management and abuse mode. Is this going to be enough or should I have to do more modifications? TIA

Its called torque multiplication, 3.73 gears multiply the in put torque 3.73 time
third gear 1.1 ratio Example: 300 ftlb X 1 X 3.73 = 1119 ftlb
Example: 300 ftlb X 1 X 4.10 = 1230 ftlb
fourth gear 0.70 ratio Example: 300 ftlb X .7 X 3.73 = 783 ftlb
Example: 300 ftlb X .7 X 4.10 = 861 ftlb
Thats why its rated at a higher towing capacity. the more torque multiplication you have the easier the vehicle will move.

[aklim]

Originally posted by gearheadnate@Oct 15 2005, 01:03 PM
Its called torque multiplication, 3.73 gears multiply the in put torque 3.73 time
third gear 1.1 ratio Example: 300 ftlb X 1 X 3.73 = 1119 ftlb
Example: 300 ftlb X 1 X 4.10 = 1230 ftlb
fourth gear 0.70 ratio Example: 300 ftlb X .7 X 3.73 = 783 ftlb
Example: 300 ftlb X .7 X 4.10 = 861 ftlb
Thats why its rated at a higher towing capacity. the more torque multiplication you have the easier the vehicle will move.

So I am short about 78 ft/lbs of torque. Would my long tube headers and Jesse's tune make up the difference? I know I have to use 93 octane fuel because all the torque management is removed.

[chrisj6]

What does 93 octane have to do with torque management??? You could use 87 with all the torque management removed.

Chris

[aklim]

Sorry, also he advanced the timing a little so I do need 93 octane or it will knock

[aklim]

Got the final weights on the unit. It weighs 5680# + 833 for water and 60 for propane and 1500 for the ATVs which gives us a grand total of 8073. The hitch is rated at 12000# with a weight distribution hitch and 600# tongue weight. The tongue weight will be about 800#. Gear ratio is going to be 4.10 which boosts the carrying capacity to 8500# and that gives me some cushion to put other stuff in it since the wife likes to pack everything INCLUDING the kitchen sink. Also will be bringing along some sort of generator for the electric power.

My rear end and front end (4X4) are 3.73 and I will be upping it to 4.10 unless someone things I should go further.

[Hit Man X]

Are you on stock 31" tires? There's not a huge jump from 3.73:1 to 4.10:1. If you're on 33" ATs or something big/heavy like that I'd go to a 4.56:1. The OD ratio in that 60E is a 30% (0.70 so it'll be just shy of 2300rpm @ 70mph.

That'd really up the towing capacity without having to swap motors or add a blower.

[aklim]

Tires are stock at 265 70 R16

[aklim]

Final weight of truck full of fluids is 5880 with me and the wife in it.