[sneaton]

i have a jku sahara with 3.21 and was planning a 2.5 inch lift and 35s. when i asked about regearing i was told if i do corsa exahust, chip, air-intake to add 70 hp that the gearing is fine and i can wait until i install my lockers to regear.

does this sound like it will work?

 

[Bogleparsons]

No, someone is full of crap.

 

[sneaton]

with the chip/programmer you can change the shift points. This guy /shop has been recommended by everyone ive met thats into jeeps and is supposed to be an expert. What gear ratio would you recommend?

 

[sneaton]

also im getting duratracs to cut down on weight....315/70/17

 

[npd337]

No way will those mods give you 70 hp. In my opinion the regear is worth way more then those mods. You probably wouldn't even be able to tell much of a difference with an exhaust and air filter. Don't waste your money unless you just want it for the sound. I don't have all that much experience with jeeps but I do know my engines as I've had several cars over 500-600 horsepower at the wheels.

 

[npd337]

O yea and I'm currently doing a 4.56 regear in my 14 jku auto running those same tires. Dropped it off yesterday I'll let you know the difference on Thursday when I pick it up.

 

[Bogleparsons]

for the 3.6 & 35's 4:56 is the ratio you want. 4.88 would be a bit too aggressive on the street.

To be honest even if you had 70 more HP the gear change is still needed, it keeps from stressing your transmission so much with the 35's.

 

[sneaton]

ok...ill tell him i want to do the regear instead to the performance upgrades...would i still need a chip/programmer? should i do lockers at the same time as the regear since i wont have to pay for the labor again? how much $ will i be looking at for locker/regear?

 

[ohioviper]

Skip right past the exhaust intake and chip .They wont do crap for your 3.6. Go directly to a regear of 4:56.

 

[ohioviper]

OP where do you live ?

 

[sneaton]

this is my DD by the way. 40 miles total on the highway daily

 

[sneaton]

indianapolis

 

[sneaton]

i was told with the larger tires that i need the chip because the computer might think my tires are flat.....is that complete BS?

 

[ohioviper]

You will need a procal to change the tire size for the transision shift points.
You will need it for a gear change as well. You have to change the gear ratio with the programer or it will go into limp mode.
Im sure there are some places there in Indy that can do gear change for good price but if not there is a good place in Columbus . He will do a front and rear regear for $650 with your parts or plus parts. Auto Gear And Axle Repair Columbus,OH - Babbitt Bearing Co., Inc.

 

[i82much]

Man if I was putting those kind of highway miles on, I would seriously consider sticking with the stock gearing and tires unless you are really serious about going wheeling.

Also, 70 horsepower my *ss.

 

[racer01]

I would start doing some serious research here and other places on the internet. If you are going to trust modifying your jeep to someone else, I'd find someone different from who has been giving you this advice.

You definitely should re-gear with 35" tires and 3.21 gears. An intake/exhaust/chip will do nothing for the fact that you will have the wrong gearing (just like having a supercharger doesn't mean you can start off in 3rd gear from a stop all the time). 3.21 gearing isn't really very well suited to stock tire diameter in my opinion, and you need even deeper gears for bigger and heavier tires. I have 4.10's with a 2013' 2-door manual and 35" BFG KM2's and it is fine for me, but many like 4.56 and I'd do the same if I was changing gear ratios now.

At a minimum you need a programmer like the AEV Procal for your automatic transmission shifting, speedometer to read properly, etc. if going to larger tires. This is dead simple to install yourself and is $160

 

[DuneSahara13]

Op...didn't you ask the exact same question in the "should I regear" thread?? To which we all answered the same way...hmmm...

 

[lando76]

If that same shop was the one that told you those add-ons will give you 70+ horsepower, I would seriously consider finding another shop to do anything else to your jeep.

I have small 35s (km2) with 3.73 gears and although it seems just fine on flat land, I still plan on regearing to take some stress off the tranny as another said.

 

[kik]

i was told with the larger tires that i need the chip because the computer might think my tires are flat.....is that complete BS?

Yes. Take the zero off of the 70 and maybe that's what you could get with all of the mods you mentioned. I think 7 hp would be optimistic also. I agree with the advice of find another shop. You would need a Procal or equivalent to take care of the tires. Skip the mods you mentioned and re-gear.

 

[JCDriller]

I ran 3.21's quite successfully with 35 Trail Grapplers for about 6 months. Really wasn't an issue until driven at elevation (Indianapolis is <1k), which is the only reason I regeared.. If you think you'll just stick around Indianapolis I'd run factory gears before deciding what to do about the lockers. You may decide to put money elsewhere.

I went with 4.88s because I plan on jumping to 37s or 38s. If you get the 35s on and are happy with the size, I'd start saving for 4.56s and Lockers. IF YOU THINK THERE IS ANY CHANCE YOU'LL WANT 37s THAN JUST DO IT, DON'T SETTLE FOR 35s! I'll be buying a second set of tires now because I thought I'd be happy with 35s.