‘11 JK Sport - Painfully sluggish!

P

Predfan75

New member
I’m new here so bear with me on the lingo and such in case I screw this up... lol

We bought this Jeep just over a year ago and it was bone stock. The get up and go was ok during the test drive but honestly not what I expected out of a V6 engine.

I’ve since lifter it just 2.5” and upgraded wheels/tires to Nitto Open Country A/T 285/70/17 with 17x9 Fuel wheels. I’ve also installed a pre-loaded tune from a Superchip programmer but man is this thing slow! I feel like I have to stand on the accelerator to really get it going. When I first put it into gear... either drive or reverse, it doesn’t even want to creep really and has this feel as if the brakes or something is dragging causing it not to want to creep. Maybe that’s normal, I have no clue and hoping for some suggestions as this thing wouldn’t pull a greasy string out of a cat’s ass... lol We absolutely love the look of the Jeep and enjoy being part of the Jeeper family... so I just need to get better performance out of it!

I appreciate any and all suggestions! Thank you in advance!
 
Predfan75 said:
I’m new here so bear with me on the lingo and such in case I screw this up... lol

We bought this Jeep just over a year ago and it was bone stock. The get up and go was ok during the test drive but honestly not what I expected out of a V6 engine.

I’ve since lifter it just 2.5” and upgraded wheels/tires to Nitto Open Country A/T 285/70/17 with 17x9 Fuel wheels. I’ve also installed a pre-loaded tune from a Superchip programmer but man is this thing slow! I feel like I have to stand on the accelerator to really get it going. When I first put it into gear... either drive or reverse, it doesn’t even want to creep really and has this feel as if the brakes or something is dragging causing it not to want to creep. Maybe that’s normal, I have no clue and hoping for some suggestions as this thing wouldn’t pull a greasy string out of a cat’s ass... lol We absolutely love the look of the Jeep and enjoy being part of the Jeeper family... so I just need to get better performance out of it!

I appreciate any and all suggestions! Thank you in advance!
Click to expand...

What trim level? (is it a Rubicon or something else?). Do you wheel it or is it a pavement princess? Your lift and bigger tires are causing your power drop (plus the 3.8l motor). You likely need to regear to solve, but we need more specifics. I know of a couple places in middle Tennessee where you could get this done (hint: not at the Jeep dealer!)
 
I second the regear. Essentially what regearing the Jeep does, is multiplies the amount of force that is being sent to the axle. The motor doesn’t have to work as hard to turn the larger tires and it will bring some of that power back.

Suoerchips isn’t a bad option. I run one on my WJ and I did notice a difference in accelerating, however it really won’t do much just on its own. I’ve heard of people having good luck with a ported throttle body. But I’ve never seen any solid proof of that.

There are a few videos floating around the internet of 3.8 JKs getting actual gains from intake and exhaust work. Exhaust would be fine, but if you wheel your Jeep I wouldn’t suggest an intake, at least not one that is an open filter design.


Sent from my iPhone using WAYALIFE mobile app
 
Torrin said:
What trim level? (is it a Rubicon or something else?). Do you wheel it or is it a pavement princess? Your lift and bigger tires are causing your power drop (plus the 3.8l motor). You likely need to regear to solve, but we need more specifics. I know of a couple places in middle Tennessee where you could get this done (hint: not at the Jeep dealer!)
Click to expand...

Torin - It is a Sport trim level. It's actually my wife's JK that I bought her after she kicked cancer's ass! So, it is definitely a pavement ride. I assumed the bigger wheels and tires was part of the issues and had I known the HP difference between the 3.8 and 3.6, I would have shopped for a 2012 or newer. I'm stuck now because she is in love with it...lol I would welcome your recommendations on the regear. I am a grease monkey on the side but don't think I want to get into that work.
 
JKbrick said:
I would put 4:88 gears in it if it were mine, and lockers while you are in there at the same time


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

JKbrick - Can you educate me on what I would gain on the gear ratio change please? Is that just for the rear axle or front as well?
Also on the locker suggestion? I have heard of the axle lockers but honestly do not know how they work, etc.
 
longarmwj said:
I second the regear. Essentially what regearing the Jeep does, is multiplies the amount of force that is being sent to the axle. The motor doesn’t have to work as hard to turn the larger tires and it will bring some of that power back.

Suoerchips isn’t a bad option. I run one on my WJ and I did notice a difference in accelerating, however it really won’t do much just on its own. I’ve heard of people having good luck with a ported throttle body. But I’ve never seen any solid proof of that.

There are a few videos floating around the internet of 3.8 JKs getting actual gains from intake and exhaust work. Exhaust would be fine, but if you wheel your Jeep I wouldn’t suggest an intake, at least not one that is an open filter design.


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

Thank you for the input. I have never used a Superchip product and wasn't sure if I needed to look into a custom tune but as you mentioned, it can't do all of the work on it's own when I have other barriers that need to be addressed. I will check out those videos, as I have had a cold air intake suggested by a hardcore Jeeper I know.
 
Predfan75 said:
JKbrick - Can you educate me on what I would gain on the gear ratio change please? Is that just for the rear axle or front as well?
Also on the locker suggestion? I have heard of the axle lockers but honestly do not know how they work, etc.
Click to expand...

what do you ultimately want to do with your Jeep? that is the starting question.
 
Predfan75 said:
Thank you for the input. I have never used a Superchip product and wasn't sure if I needed to look into a custom tune but as you mentioned, it can't do all of the work on it's own when I have other barriers that need to be addressed. I will check out those videos, as I have had a cold air intake suggested by a hardcore Jeeper I know.
Click to expand...

If you wheel your Jeep, especially in dusty environments, do NOT get an open element style intake. Get one that is sealed. I run an AFE intake on my 17 JK and I went to clean the filter the other day and there was nothing beyond ordinary dust on it, and the intake tube was free of debris.
 
longarmwj said:
If you wheel your Jeep, especially in dusty environments, do NOT get an open element style intake. Get one that is sealed. I run an AFE intake on my 17 JK and I went to clean the filter the other day and there was nothing beyond ordinary dust on it, and the intake tube was free of debris.
Click to expand...

Great suggestion! Thank you.


Sent from my iPhone using WAYALIFE mobile app
 
From the sound of it, you may have the 3.21 gearing. My JKUR (4.10) is certainly not "peppy" but I find it livable even with my 35" tires on heavy beadlocks. Unless there is something wrong with the power output, that would be my guess.

And it's always nice to speak with a Predators fan. :beer:
 
sm31 said:
From the sound of it, you may have the 3.21 gearing. My JKUR (4.10) is certainly not "peppy" but I find it livable even with my 35" tires on heavy beadlocks. Unless there is something wrong with the power output, that would be my guess.

And it's always nice to speak with a Predators fan. :beer:
Click to expand...

Absolutely! Go PREDS! I will need to figure out which gear ratio I have and look at options from there. Thank you!


Sent from my iPhone using WAYALIFE mobile app
 
New gearing will make a huge noticeable difference, intake, exhaust & tune in comparison, not so much. Google "Jeep JK 3.8 Gear Chart" be sure to use the one for the automatic and keep yourself in the middle of the green area for a on street daily driver. Be sure you measure your tire size manually for the calculation. The 3.8l engine makes decent power, its the 42RLE automatic trans that kills the whole driving experience. I would skip the bolt-ons and go straight for gears.
 
Predfan75 said:
That seems to be the unanimous suggestion. Thank you!


Sent from my iPhone using WAYALIFE mobile app
Click to expand...

Ya, the super charger bit was a joke (for the love of GOD do not do that). You likely have 3.21 gears (which means you didn't have much torque in the first place). I would explore getting regearing done. For a pavement princess, you likely can go with 4.56 or 4.88 gears (more torque on the low end and higher RPMs at the high end). I went from 3.21's to 4.88's on a 3.8l and it was night and day.

If there is a chance you may start wheeling it, you might want to look into the more expensive option of replacing the front Dana 30 axle and housing with a Dana 44. If you wheel the D30, you will likely break it over time and it is expensive to regear twice. :)

I would check with Essentially Offroad in Murfreesboro (I know, the is hell and gone for you, but they are a good shop) for pricing.

I am a huge Preds fan, still play hockey and went to every home game in the 2017 cup run, love the handle man!
 
You must log in or register to reply here.
Top Bottom