Coyote with 6R80 and 33” tires axle ratio

[Gn1]

What is a street cruiser and light off road axle ratio for coyote swap 6r80 and 33” tires?

 

[.94 OR]

My '12 F150 is similarly equipped, heavier rig and set up for towing, but it runs 3.73. 3.55's might be a better fit due to the weight and minimal towing exposure.

 

[DirtDonk]

What are the gear ratios of the 6R? I’m sure it’s been posted up here before, but I don’t have it memorized yet.

 

[admin]

Ford 6R80 transmission ratios:

1st = 4.17
2nd = 2.34
3rd = 1.52 (or 1.57 per some sources)
4th = 1.14
5th = 0.87
6th = 0.69

Here's a tech article on it by @nvrstuk
https://classicbroncos.com/forums/a...-trans-into-a-bronco-behind-any-sbf-engine.2/
.
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[Broncobowsher]

My '12 F150 is similarly equipped, heavier rig and set up for towing, but it runs 3.73. 3.55's might be a better fit due to the weight and minimal towing exposure.

Maybe heavier, but I bet is more aerodynamic and less rolling resistance.
It;s been too long since I last drove a Coyote to remember where it is happy at. And I am pretty sure the last one I drove was direct inject, which makes them happier being lugged down lower than the port injection lets them.

 

[DirtDonk]

What is a street cruiser and light off road axle ratio for coyote swap 6r80 and 33” tires?

What gear ratio is in the Bronco now?
Whatever it is, use it at first, then decide once you've driven it. It might need lower, or it might need higher, but only you will know for sure.
And even at that point, you can still mess around, by changing only the rear 9" (if that's what you still intend to use?) gears and see how it acts on the street.
Once the happy-camper gearing is found, then you can change the front.

Unless it's been messed with, a '69 could have come from the factory with either 3.50-ish, 4.10-ish, or 4.56-ish gearing. Seemingly right in the middle of what you'd want.
But I'm thinking that for an even remotely usable overdrive, you're going to want to stay in the 4's and up (numerically speaking) to remain relevant in overdrive.
The 4.17 first gear is going to let you rocket off the line even with the 3.50 gears, but it would seem to be a dog in the upper gears. With stock 3-speed transmissions and no overdrive, 3.50's were the bane of our existence with 33 inch tires for many years.
I have 4.56 with 31" tires, which is an extreme example and totally biased towards off-road capabilities. But it's still a pleasure on the street (when it's not spinning a tire that is) with a lesser overdrive than your 6R has.
If I had to choose ahead of time (not my preference) I'd err to the side of 4.11's for your stated use.

But I'd still wait until you can drive it, then decide.

Paul

 

[DirtDonk]

Ford 6R80 transmission ratios:

Here's a tech article on it by @nvrstuk
https://classicbroncos.com/forums/a...-trans-into-a-bronco-behind-any-sbf-engine.2/

Thanks Jon!

Paul

 

[Bruners4]

I drove our '24 F150 w/5.0 today and watched the RPMs. Also was driving straight into a 30 mph headwind at times. Flat straight roads w/o headwind would run as low as 1200 rpm. Add headwind and it downshifted to 1900 ~ 2100 rpm.
Thinking about this and knowing how my '68 is, I would be gearing it to run 65 mph at 1800 rpm at a minimum in top gear. Use this site to help calculate your gear ratio. Note: 33" tires are 32.5".

Gear Ratio Calculator

 

[Chiclassics]

4:11 gives you 2017 cruise rpm which within 2000-2200 performance range for coyote

 

[Gn1]

Thanks for the comments. I have 4:56 gears that I put in a couple years ago now for the 200 and 3 speed manual pooch set up. I will be going in it anyway to put a tru trac. But if I can avoid changing the ratio on both axles that for no good reason that is bonus. There seems to be a 4:11 to 4:56 debate that I am trying to sort out.

 

[DirtDonk]

In that case, there’s no debate. Run what you brung. Then go into it to add the diff if you need.
And even then, only if you’re sure you need a limited slip differential.
Sometimes one-legin’ it is the better option when you have that much power on tap.
Will this be a stock Coyote, or modified?

 

[Broncobowsher]

Another run what you brung. At least wait until you drive it and see what it feels like. You are in the ballpark, if not already at home plate.
Might even get into splitting hairs if the tires are just labeled 33" or actually measure 33"

Just adding a limited slip to an existing ratio, no messing with pinion depth or preload. Just side bearing preload and dial in backlash.

 

[Gn1]

Yes I like what you guys are suggesting. Thank you!

 

[rjrobin2002]

My 6r80 with 35s feels great in my 2011 f150 with a coyote.

It's really amazing how much more forgiving gear ratios are with the 6 spds compared to 3 or 4 spd autos.