An Engineer's Ultimate Guide To 3.21 VS 3.92 Axle Ratio

[TNRamGuy]

Basically what he's saying is that the 3.21 gear set is superior.

Must be tough, not even having your near perfect truck! I am jealous of your indigo interior to be honest, that is going to be awesome

 

[theblet]

That's just what 3.21 owners say to try and cover up their own inadequacies

Aww poor things in denial. Sry bout your Vienna sausage manhood

 

[Mountain Whiskey]

Exactly - not to mention, a new Ram with 3.21s will still outpull 90% of half-ton trucks built in the last 30 years and get better gas mileage doing it.

Yea but they will out pull 0% of Ram 1500s with 3:92 gears.

 

[theblet]

Yea but they will out pull 0% of Ram 1500s with 3:92 gears.

Not after we get rid of this pesky speed cap!

 

[HSKR R/T]

Not after we get rid of this pesky speed cap!

I'd be willing to bet the 3.92s might actually have a higher top end without a speed limiter as they could overcome the drag easier than 3.21s

 

[HemiDude]

Does anyone know where I can find a 3.92 Gear decal? I don't need anyone thinking I might have 3.21's.

My SRT Challenger had "392" emblems on the fenders. It never occurred to me that I was actually bragging about my gears!

 

[HSKR R/T]

Aww poor things in denial. Sry bout your Vienna sausage manhood

No just pointing out the obvious when 3.21 owners try to deflect their own inadequacies

 

[BowDown]

I'd be willing to bet the 3.92s might actually have a higher top end without a speed limiter as they could overcome the drag easier than 3.21s

Nope. look at the 1st page post 17, top speed would likely occur in 4th or 5th given the hp and aero. All the 3:21 truck would need to do is be in 4th when the 3:92 is in 5th which actually gives the 3:21 truck better gearing. Would be the same for 5th or 6th as well, advantage....3:21

The Hellcat challenger guys ran into this with the 2:62 vs the 3:09 gear during airport races. 3:09 cars hit a dead spot around 160 mph and slowed dramatically while the 2:71 cars didn't shift and were able to pull the gear because they were still in peak power.
Here's one example but there's many more https://www.hellcat.org/threads/redeye-vs-hellcat-3-09-vs-2-62-1-mile-race.230459/#post-4110577

 

[HSKR R/T]

Nope. look at the 1st page post 17, top speed would likely occur in 4th or 5th given the hp and aero. All the 3:21 truck would need to do is be in 4th when the 3:92 is in 5th which actually gives the 3:21 truck better gearing. Would be the same for 5th or 6th as well, advantage....3:21

The Hellcat challenger guys ran into this with the 2:62 vs the 3:09 gear during airport races. 3:09 cars hit a dead spot around 160 mph and slowed dramatically while the 2:71 cars didn't shift and were able to pull the gear because they were still in peak power.
Here's one example but there's many more https://www.hellcat.org/threads/redeye-vs-hellcat-3-09-vs-2-62-1-mile-race.230459/#post-4110577

Since nobody really knows what the aero limited top speed is on these truck, you are just making a WAG with what gear the trans would be in

 

[BowDown]

Since nobody really knows what the aero limited top speed is on these truck, you are just making a WAG with what gear the trans would be in

Wouldn't matter.
You said gear wise the 3:92 truck would be at an advantage. Unless both trucks could max out in 8th gear, the 3:21 truck would always have the advantage as the gearing one gear down from the 3:92 truck has the 3:21 truck with superior gearing as the chart clearly displays. After 1st gear, the 3:92 truck has zero advantage gear wise because of the trans.

 

[HSKR R/T]

Wouldn't matter.
You said gear wise the 3:92 truck would be at an advantage. Unless both trucks could max out in 8th gear, the 3:21 truck would always have the advantage as the gearing one gear down from the 3:92 truck has the 3:21 truck with superior gearing as the chart clearly displays. After 1st gear, the 3:92 truck has zero advantage gear wise because of the trans.

Since you don't k ow what the aero limited top speed is, once again, you are just assuming the 3.21 truck would be a gear lower. Depending on the speed and shift points, there is a distinct possibility the 3.92 could be hitting top speed at the top of 6th where the 3.21 would have to shift into 6th because it had too much RPM in 5th due to higher gear ratio

 

[theblet]

I'd be willing to bet the 3.92s might actually have a higher top end without a speed limiter as they could overcome the drag easier than 3.21s

Maybe with 37’s so you’re final drive will be better for top speed. But the rotational mass of the load range f tires would prob prevent any gains associated.

 

[Mountain Whiskey]

Wouldn't matter.
You said gear wise the 3:92 truck would be at an advantage. Unless both trucks could max out in 8th gear, the 3:21 truck would always have the advantage as the gearing one gear down from the 3:92 truck has the 3:21 truck with superior gearing as the chart clearly displays. After 1st gear, the 3:92 truck has zero advantage gear wise because of the trans.

Or the little blonde chick driving the truck with 3:21 gears would hit a slight head wind and BOOM. Dead in her tracks.

 

[ferraiolo1]

Nope. look at the 1st page post 17, top speed would likely occur in 4th or 5th given the hp and aero. All the 3:21 truck would need to do is be in 4th when the 3:92 is in 5th which actually gives the 3:21 truck better gearing. Would be the same for 5th or 6th as well, advantage....3:21

The Hellcat challenger guys ran into this with the 2:62 vs the 3:09 gear during airport races. 3:09 cars hit a dead spot around 160 mph and slowed dramatically while the 2:71 cars didn't shift and were able to pull the gear because they were still in peak power.
Here's one example but there's many more https://www.hellcat.org/threads/redeye-vs-hellcat-3-09-vs-2-62-1-mile-race.230459/#post-4110577

Unless you have a bolt on intake that gives you 30+ hp lol


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[HSKR R/T]

Unless you have a bolt on intake that gives you 30+ hp lol


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Only if you think they will be in different transmission gears. I love how the 3.21 guys latch on to the whole, my truck has better gearing if I'm one gear below a 3.92 truck. Well, no ****.

 

[BowDown]

Since you don't k ow what the aero limited top speed is, once again, you are just assuming the 3.21 truck would be a gear lower. Depending on the speed and shift points, there is a distinct possibility the 3.92 could be hitting top speed at the top of 6th where the 3.21 would have to shift into 6th because it had too much RPM in 5th due to higher gear ratio

You can manually put/keep the 3:21 truck in a gear lower. The +/- button thingies on the wheel. Keep trying

 

[HSKR R/T]

You can manually put/keep the 3:21 truck in a gear lower. The +/- button thingies on the wheel. Keep trying

And I can't do that with 3.92 gears?

 

[BowDown]

Only if you think they will be in different transmission gears. I love how the 3.21 guys latch on to the whole, my truck has better gearing if I'm one gear below a 3.92 truck. Well, no ****.

So, if you're in 8th and I hold 7th, guess where we are? Me with a slightly lower gear than you. Outside 1st, that's the case in every gear

 

[BowDown]

And I can't do that with 3.92 gears?

Yep but you'd be out of motor, math.
But wait , there's more! I can do that for every gear till you're out of gear or motor

 

[HSKR R/T]

Yep but you'd be out of motor, math.
But wait , there's more! I can do that for every gear till you're out of gear or motor

These trucks will be aero limited before they hit 8th gear. So any advantage you think you have by being in a lower gear doesn't matter as much. There will be a time when both trucks will be in the same gear at the same speed as the 3.92 trucks reaches top of gear and 3.21 trucks has to shift into next higher gear, losing any advantage it may have had. You can't change the rules of physics