I know that there are very many topics on gears, but before you remind me there is a "search" tool, this one is unique.

K so here is what I have; 2011 JKU 3" lift on 35's, auto trans, Banks intake and MBRP cat back exhaust. I'm going to do gears very soon and I was dead set on 5.13s over 4.88s.

HOWEVER; here is my issue. Everyone loves the 5.13s and says they are the greatest RPM range at 60-65mph. Well this jeep sees way more 80MPH than 60-65MPH. Also, I'm not a rock crawler, I'm in the dunes or on desert roads. Additionally, I plan on adding a RIPP Supercharger once avail for the 2011.

So with all this in mind, would I be better off going the longer ratio of 4.88s since I'll have the boost to power through it? I just don't want to be doing 80MPH on the highway in the 3500+ RPM range sucking down gas like crazy.

Oh and yes I'm aware that the RPM difference between 4.88 and 5.13 is only 100RPM at highway speeds, but that's at 60-65MPH. Again I'm asking about the 75-80MPH range.

Thank you guys for your help. This seriously is the best forum to be a part of, from the administrator all the way down to newbies like me

 

4.88's might suit you better do to how you will be driving it. The supercharger will more than compensate for the torque and power lost with the higher gearing

 

You might even be good with higher gears, maybe 4:56 or 4:10's, you might want to PM RIPP and see what they say.

 

I vote for 4.56 or 4.88 because you will ha e the extra power you wont need that low of gears if you want to be going 80 mph

 

I have an auto, 4.88's with 35's and do a lot of freeway 70+ mph, at 85 with no fighting headwinds it's good, but with headwind rpm's cliimb pretty quick. I was able to cruise 92 mph, think RPMs were about 3200, can't remember.

Also, with 4.88 on climbs - I travel to Colorado from Tx, I still get some downshift and at higher speeds, the RPM's really jump to the point torque flattens out quickly.

I tested the setup pretty hard on I-70 mountain pass and redlined a couple of times - engine system took over and dropped speed but gotta say, it's a pretty strong engine/trans

I plan to go the Hemi route with 37's to get back to stock ratio. When I was researching gears, everyone said 5.13's but after talking to Hemi owners and install shops, many said they remove the 5.13's and install 4.56 or 4.88.

With the RIPP's added power, I'd recommend the 4.56 so you can still downshift and not jump the RPM's. With the added power, your RPM's should be in the powerband when cruising + get decent mileage once you stop laying heavy on the skinny pedal ...

 

Ah yes! You guys are awesome. This is exactly what I've been looking for. I think ill go with 4.88s to give me a little of both worlds. Especially since i have to wait a couple months for the supercharger.

 

I've got a an 07 JKU, auto, 4.10's, RIPP and will be adding a 3 inch lift and 35's this weekend. Since I'm pretty flat around here, I was planning on just keeping the stock gears and counting on the supercharger to make up the difference.

Once I get the new rubbers on, I'll let you know how it feels and hopefully help ya out!

 

Word buddy. How do you like the RIPP?

 

I was told by RIPP they recommended 5.38s for 37s with an auto.

 

They told me the same, but i have 35s and i am more focused on midrange to topend