Which rear end gears should I do? Coyote guys please chip in

[Iwannagofast]

I am building my axles right now and the builder asked if I want to go with the stock gears in the rear of 3.50's or change them for something maybe a little different?

 

[Apogee]

You should definitely do gears...they're kinda necessary. As for which ratio, that would depend on the engine/trans combo, tire size, intended use, personal preference, etc.

 

[sykanr0ng]

Just from looking at the (usually recommended) Mustang Coyote torque and horsepower numbers and what RPM (4250 and 6500) they are measured at I would say it is a real case for Don't Fear The Gear! whatever transmission and tire size you use.

 

[Iwannagofast]

You should definitely do gears...they're kinda necessary. As for which ratio, that would depend on the engine/trans combo, tire size, intended use, personal preference, etc.

Just from looking at the (usually recommended) Mustang Coyote torque and horsepower numbers and what RPM (4250 and 6500) they are measured at I would say it is a real case for Don't Fear The Gear! whatever transmission and tire size you use.

AX15 manual trans with 35" tires. Daily driving or casual. Some light off road every now and then. I'm thinking 4.10's

 

[bronconut73]

Gosh I don't know man....that may not be low enough to use your overdrive uphill unless your cruising at 90 mph, lol.
But it depends on what you want to do with your rig.
I run 4.11's with 35's without OD. It is really great but I am running about 3400 rpm at highway speeds here in central Florida. Overdrive would bring me down to about 2550 rpm at highway speeds. That "does" sound nice.

But deeper gearing will be more fun. Going from 3.50's to 4.11's blew me away. MUCH quicker! Like wow, its what my eb really needed for a really long time.
If I were to get an overdrive I would probably want to go a little lower. My Windsor makes great low end torque so I guess I could get away with a little less low axle gears. But I lot of these fellers will be telling you to go to like 4.88's or so with overdrive and 35's.

 

[sanndmann3]

If I recall correctly, 35" tires and 4.56 gears get you back to a stockish final drive ratio (3.50 gears and 28"(?) tires). Overdrive might get you thinking 4.88 or 5.14s?

 

[sykanr0ng]

I would expect that you will end up being unhappy with anything less than 4.88 gears with that tire size, that OD transmission and that engine.

It would be 5.13 gears if it was mine.

 

[Iwannagofast]

Icon uses 4.10 with 33's. I wonder 4.56 or 4.88?

 

[landshark99]

4.88's with that tire size and transmission.

 

[Apogee]

With those combinations, anything in the 4.56 to 5.38 could work pretty well IMO. I would look at where you want to be in OD at your top crusing speed and go from there..4.88/5.13's look pretty good on the calculator assuming you never really need to go over 90-100 MPH. If you recam the Coyote to sacrifice a little HP for lower-RPM torque, then the 4.56/4.88 might be your best options.

 

[klawrence]

I have the Coyote/4R70W combo running 4.56 with 35s. Almost perfect, it I were to do it over, maybe 4.88s

 

[bronconut73]

I have the Coyote/4R70W combo running 4.56 with 35s. Almost perfect, it I were to do it over, maybe 4.88s

Cannot beat "real world" experience like that!

 

[rguest3]

35s, Overdrive, Coyote Motor - 4.88 gears

 

[Broncobowsher]

I have the Coyote/4R70W combo running 4.56 with 35s. Almost perfect, it I were to do it over, maybe 4.88s

That sounds about right.

Still fighting bad aero, something that mustangs and F150s are not fighting. It takes HP to push wind and the only way to get HP is more RPM or more torque. You are not going to get a coyote to make low end torque like a diesel, you will need a little more RPM instead. The torque below 2000 RPM is good, but not much different then any other gasoline V8 of similar size.

 

[jmangi62]

If I recall correctly, 35" tires and 4.56 gears get you back to a stockish final drive ratio (3.50 gears and 28"(?) tires). Overdrive might get you thinking 4.88 or 5.14s?

^^^^^ Yep. I have 35s with a 3550, 4.56s aahhhh! perfect!

 

[Broncobowsher]

^^^^^ Yep. I have 35s with a 3550, 4.56s aahhhh! perfect!

But what engine?

 

[jmangi62]

No coyote, mildly built 302.