Cpt. Flapjack

4.88s and 33s on a 6 speed 2dr?

Anybody running this set-up? I'm looking at ARB lockers and figure if I have to pay to get them installed, I might as well get ready for 35s. The problem is that my 33s have a lot of life left on them and I don't have the cash to replace them and do the lockers.

I am currently happy with the performance of the 3.73s I have now with the 33" tires, but am concerned with the drivability with the 33s and 4.88s.

Anyone have experiance with this set-up?

Thanks,
Cpt. Flapjack

opdsgt

ALL you need to know right here my man. I run 4.88s and 33s. On purpose.

https://www.jk-forum.com/forums/modified-jk-tech-2/my-4-88-gear-review-98283/

rome07JK

im stuck between getting 4.88 and 5.13s....i cant decide.

Slightlymodified

I would go with the 4.88's unless you will be upgrading your tires to 35's or 37's in the near future.

rome07JK

well i do plan on going to 35's for sure in the future

Mark Doiron

I think that 5.13s, 35s and a six speed makes first gear too short. I haven't lived with it, but TORN and RescueX both have 4.88s with that combo, and I've ridden with both of them. They are delighted with 4.88s. I'd say, if you're contemplating 5.13s, see if you can't find someone local who has that combo to let you have a test drive.

BLK-JK23

4.88's and 33's scream RPM to me.. but who knows... id buy the 4.88's sit on them,
when you can buy tires get them installed

TEEJ

If you want to simulate the feel of a lower gear set, just down shift...it will be like you're one gear lower (RPM in 6th with the new gears will be like 5th is now, and so forth, you can start off in 2nd instead of 1st, etc...)



For example, going from 3.73's to 4.88's raises the rpm in any given gear by ~ 23.5%

If you are cruising on 3.73's at 2,500 RPM, on 4.88's, RPM would jump to ~ 3,268 RPM.

The same above 3.73 + 2,500 rpm, with swapped in 5.13's would jump the RPM to ~ 3,439 RPM. (A ~ 27.3% Jump over the 3.73's)

3,439 RPM minus 3,268 RPM = 171 RPM difference.

So, the difference between 4.88's and 5.13's will be only ~ 171 rpm

The difference between 3.73's and 4.88's will be ~ 768 RPM

The difference between 3.73's and 5.13's will be ~ 939 RPM

and so forth.



If you also go from 32's to 35's, you DROP the RPM by ~ 8.6%

So, for the same 2,500 cruise, and 4.88's and 35's...

The 35's DROP you by ~ 214 RPM (To ~ 2,286 RPM)...

....and the 4.88's RAISE you by ~ 768 RPM...

...so your net RISE in RPM is ~ 554 RPM



If you shift from 6th to 5th, you should see a similar change.

IE: 6th will feel more like 5th, 5th will feel more like 4th, and so on.

Conversely, cruising at hwy speeds will feel the same, as in 6th, you will really be cruising along like you were in 5th as far as mpg goes, etc.

If you want to imagine the 4.88's vs 5.13's...the net rise would be ~ 3.8% more RPM at any given gear.


I typically don't have the cash for new gears, so I do a free gear change, by simply down shifting.

If I want to - I can pretend I don't have a 6th gear, instead of changing it to what I now get in 5th gear, etc....and instead of having a 6th gear that works like a 5th gear, I can just shift down to my real 5th gear, and get the exact same effect.

Of course, when I get to 1st, I am out of gears to shift down to, leaving me a bit faster through the rock gardens, etc.






Hope that adds some perspective.

JPop

You also need about 3-5 extra horsepower to roll a 10% larger tire, so in round numbers you should plan on having an additional 150 rpm.

Cpt. Flapjack

Thanks, thats exactly what I was looking for.