Re-gear, Supercharge or both??

[Phljeeper]

I have a JTR and have upgraded to 37" tires. While the stock 4.10s do fine in normal driving, they struggle towing when hitting hills and the truck seems to lag a bit off the line or shifting putting the RPMs too low on gear changes. This is only noticeable when towing. So first I will say that many on the forum have said stock 4.10s and 37s with the automatic do just fine and I will agree completely. I even towed my 4700lb camper this past weekend a total of about 8 hours on the highway on mostly flat ground and was impressed with how well it actually did. But I want at minimum stock power back (I know it wont be completely stock due to my added weight of the bumpers, tires, etc) and would like to improve the towing in the mountains. So here is my question (which I think I know the answer to):

1. Regear to 4.88 or 5.13 (I think I will stick with 4.88)
2. Supercharge and keep the 4.10s
3. Regear first then supercharge later if I still want more power

With that said, anyone running 4.88s and a supercharger? Thoughts on if I plan to supercharge in the future should that change the choice in gears now? How about anyone running 4.10s and a supercharger with 37"+ tires?

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[bastage]

My plan is for option 3..

Make the engine not work as hard before giving it more oomph.. I will wait on the SC until my warranty is closer to being up.

 

[Phljeeper]

My plan is for option 3..

Make the engine not work as hard before giving it more oomph.. I will wait on the SC until my warranty is closer to being up.

That is my thought. I am struggling though as the gearing isnt too bad and was thinking maybe supercharging would make me not need to regear. I know I have read that isnt the best answer but with 4.10s and the 8 speed the opinion may be different from older JKs using the 3.6.

 

[bastage]

That is my thought. I am struggling though as the gearing isnt too bad and was thinking maybe supercharging would make me not need to regear. I know I have read that isnt the best answer but with 4.10s and the 8 speed the opinion may be different from older JKs using the 3.6.

Adding more power without regearing is just more prone to failure I would think. More likely to break something.

 

[Klutch]

I would absolutely suggest re-gearing. Bigger gears make a HUGE difference and, if done right, they will last hundreds of thousands of miles.

A supercharger is very expensive and, if it doesn't blow up the engine, it will most certainly shorten the lifespan. It will also make your vehicle less reliable. I'm not anti-supercharger, but the fact is you will have issues. Superchargers can be reliable, but not as reliable as what the Jeep engineers built.

 

[anavrinIV]

adding more power will just put more stress on the rest of the drivetrain. Enough to cause an issue is really dependent on how much more you put through it, but either way the gearing is the problem, not the power

 

[hjdca]

I have a JTR and have upgraded to 37" tires. While the stock 4.10s do fine in normal driving, they struggle towing when hitting hills and the truck seems to lag a bit off the line or shifting putting the RPMs too low on gear changes. This is only noticeable when towing. So first I will say that many on the forum have said stock 4.10s and 37s with the automatic do just fine and I will agree completely. I even towed my 4700lb camper this past weekend a total of about 8 hours on the highway on mostly flat ground and was impressed with how well it actually did. But I want at minimum stock power back (I know it wont be completely stock due to my added weight of the bumpers, tires, etc) and would like to improve the towing in the mountains. So here is my question (which I think I know the answer to):

1. Regear to 4.88 or 5.13 (I think I will stick with 4.88)
2. Supercharge and keep the 4.10s
3. Regear first then supercharge later if I still want more power

With that said, anyone running 4.88s and a supercharger? Thoughts on if I plan to supercharge in the future should that change the choice in gears now? How about anyone running 4.10s and a supercharger with 37"+ tires?

There are two things you can do to get the stock acceleration back with 37s on the JT Rubicon that came with 4:10s -- not including a supercharger.

1. Re-gear to 4:88 or 5:13
2. Keep the weight as low as possible on all 4 tires and rims.

The closer you can get to 90 lbs for each rim and tire (25 lbs for each rim and 65 for each tire on the JT Rubicon with 33s), the closer you will be to stock power. Of course this is an almost impossible weight to get to, but, you can get much closer or much farther based on you rim and tire decisions.
Remember - theoretically, even if the tires and wheels are larger, if the final gearing is the same, and the final weight on each wheel is the same, no acceleration is lost -- except for friction, wind drag, and other parasitic losses.

 

[BLK HOLE]

Regear...power adders are expensive, require tuning and shorten the life of the engine.

 

[Phljeeper]

Thanks for the replies. This was my thought as well and I will stick with my current path to regear to 4.88. Appt is next week.

 

[BLK HOLE]

Thanks for the replies. This was my thought as well and I will stick with my current path to regear to 4.88. Appt is next week.

I've read NUMEROUS reviews on 4.88s and most everyone regrets it if they have a chance to ride in 5.13s. FYI.

 

[SloW8]

I loved 4.88s and 37s in my JKU. If I was going to wheel, I would have gone to 5.13 or 5.38. But as a daily driver, I kind of feel like the 4.88s were the sweet spot. That was never towing, just mostly daily driving and the weekend warrior wheeling.

With the 8spd, I think you would be great with 4.88s. Unless you plan on wheeling a lot, then I'd get into the 5s.

 

[Klutch]

I've read NUMEROUS reviews on 4.88s and most everyone regrets it if they have a chance to ride in 5.13s. FYI.

Brad the TrailRecon guy went with 5.13 gears on his Gladiator and I'm pretty sure he's running 37s. Look for the video on his channel. His MPG actually improved with the new gears and, unlike previously, his transmission actually shifted into 7th and 8th gear. So I too am thinking 5.13s are the way to go with 37" tires.

 

[BLK HOLE]

I loved 4.88s and 37s in my JKU. If I was going to wheel, I would have gone to 5.13 or 5.38. But as a daily driver, I kind of feel like the 4.88s were the sweet spot. That was never towing, just mostly daily driving and the weekend warrior wheeling.

With the 8spd, I think you would be great with 4.88s. Unless you plan on wheeling a lot, then I'd get into the 5s.

I have 4.88s on my JKUR and I still wish I would have gone 5.13s for rocks and road. 37s as well.

 

[JTPatriot]

Here is my story with no commitment on which to go with as I am not sure.
https://www.jeepgladiatorforum.com/...4-88-gears-my-review.31785/page-5#post-550482

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