New to the Wrangler world and the forum with questions about the 3.8

Chris

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Should I have avoided the 3.8L engine?

I realize that in saying this I may offend some members here which truly isn't my goal.

I've driven both extensively and the 3.6 is superior to the 3.8 in every way imaginable. All the 3.8s I've driven are complete dogs and not much better than the 4.0 engines that preceded them. I always tell people to avoid buying 3.8 JKs if they can. Sure, you can get more power out of them with a supercharger or turbo, but the 3.6 is just phenomenally better in every way. It has nearly 100 more horsepower and it shows.
 

Dirty Dog

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I sprung for the Pedal Commander and it's made a huge difference.
So, while 202hp doesn't seem like much, keep in mind it has little to do with your JK being able to get out of its own way, taking 20 minutes to get up to speed on the interstate on-ramp or being able to accelerate from a standing start before the light changes. In reality, it has everything to do with torque- which is directly related to your gearing, and throttle response.
This is true. Kind of. Sort of. But not really.
Torque is considered the more important number, but the two are inextricably linked. Because torque is measured, and HP is nothing but a mathematical concept derived from the measured torque. HP is Torque X RPM/5252. Which is why the two lines on a dyno chart always meet at 5252 RPM. And why higher RPM equals more power (within the mechanical limitations of the valvetrain and rotating assembly). Increase torque, and you increase HP.

Getting out of your own way is indirectly related to gearing. Gearing is a torque multiplier, but the baseline torque is still the determining factor. There is no combination of gearing that will allow the 237lb/ft produced by the JK 3.8 to keep up with the 711lb/ft produced by my Vette, even if I leave the Vette in 4th gear and eliminate the torque multiplying effect of the gears.

Gearing is a great thing. But it's no substitute for actual power.
 
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Dirty Dog

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I realize that in saying this I may offend some members here which truly isn't my goal.

I've driven both extensively and the 3.6 is superior to the 3.8 in every way imaginable. All the 3.8s I've driven are complete dogs and not much better than the 4.0 engines that preceded them. I always tell people to avoid buying 3.8 JKs if they can. Sure, you can get more power out of them with a supercharger or turbo, but the 3.6 is just phenomenally better in every way. It has nearly 100 more horsepower and it shows.
Agreed. As her Jeep approaches 200,000 miles, I'm nudging Mrs. Dog towards swapping in either a 3.6L or an LS when her 3.8L gives up the ghost.
 

Dirty Dog

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Yep, a bad 3.8 is a perfect excuse for a V8 swap or an upgrade to the 3.6. The 3.6 really is a great engine for all intents and purposes.
It's still underpowered for a vehicle with the aerodynamic characteristics of a barn, but it's certainly better. Or maybe I'm just spoiled...
 
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JerryD

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I'm a contrarian here... I was hesitant to drop the dough for a Pedal Commander (although I liked the bluetooth capability) so I tried 9-Drive. Yeah, the response was better. But after driving it a while, it just felt jittery. Not like a carb/cable set up which is probably what I was expecting. Also, after getting codes for the 3rd time, I sent it back. I was really hoping it would be a good purchase, especially when used while passing . I hate the drive-by-wire response in those situations.

I know people think they're great and all, but color me unimpressed.

I accept the fact that a JK isn't a hot rod, not everyone embraces that reality. :cool:
 

Dirty Dog

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Yeah it’s a bit of a dog (3.8). Is it worse in a JKU? Doesn’t seem that bad in my 2 door.
Of course it's worse. A JKU is heavier. In a 2-door, soft top, manual trans JK without any added metal it will feel better (though it's still a dog...) than in a 4-door, hard top, auto trans JKU with a bunch of aftermarket mods.
 
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Dirty Dog

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Don’t know about Colorado but speed limit here is 70. Do that easily. Usually don’t do that in the woods. Never been confused with a sewing machine factory😝
The signs here say 75, but that's just a suggestion, right? My Vette has never been confused with a sewing machine factory either. :)
 
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BigAL07

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Heard that. Can’t speak on vettes. I put them up there with 300 hundred thousand dollar motor homes that sit in people’s driveways 51 weeks a year. If I can’t use it 365, it’s useless to me. Besides the ladies already know I have lots of money and a huge member. Wouldn’t really serve ME any purpose anyway 🍺
 
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Speartip

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I'm a contrarian here... I was hesitant to drop the dough for a Pedal Commander (although I liked the bluetooth capability) so I tried 9-Drive. Yeah, the response was better. But after driving it a while, it just felt jittery. Not like a carb/cable set up which is probably what I was expecting. Also, after getting codes for the 3rd time, I sent it back. I was really hoping it would be a good purchase, especially when used while passing . I hate the drive-by-wire response in those situations.

I know people think they're great and all, but color me unimpressed.

I accept the fact that a JK isn't a hot rod, not everyone embraces that reality. :cool:
Thanks for the Intel . Was kinda debating about the whole pedal
commander / 9 Drive . So response intermittent at times and
caused a few codes. Thats all I needed to hear to put this idea
on the back burner .
While gearing isn't a replacement for HP or Torque . It does allow
the Jeep to climb hills, manoeuvre over obstacles and get up to
speed on the HWY much easier .

100 percent not a hot rod , Aerodynamics of a brick. Its a
Jeep that many of us take off road into
the bush . Max speed 10-20 MPH . Lol
 

Speartip

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I realize that in saying this I may offend some members here which truly isn't my goal.

I've driven both extensively and the 3.6 is superior to the 3.8 in every way imaginable. All the 3.8s I've driven are complete dogs and not much better than the 4.0 engines that preceded them. I always tell people to avoid buying 3.8 JKs if they can. Sure, you can get more power out of them with a supercharger or turbo, but the 3.6 is just phenomenally better in every way. It has nearly 100 more horsepower and it shows.
But I guess the ultimate question. Is the 3.6 more reliable
than the 3.8? On average will a 3.6 last longer than a 3.8
before a major rebuild is needed.
This is a question I asked myself more than once as considering
a 3.6 JKU but as I read the forums on here. Many many issues
one way or another with 2012+ JKU's. If not the motor, suspension
related problms or something in the electrical is messing up.
 
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Largehit71

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Of course it's worse. A JKU is heavier. In a 2-door, soft top, manual trans JK without any added metal it will feel better (though it's still a dog...) than in a 4-door, hard top, auto trans JKU with a bunch of aftermarket mods.
Worded that wrong. Is it that much worse is what I was getting at. I need to proofread before I post. Lol
 
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MacGuyver

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A thing I would do is change out the plugs and wires. It's not something a person thinks about, and the power boost I got when I did that for my 3.8 was quite noticeable. It's pretty easy on the 3.8. Mine is going strong at almost 210K

As has been stated, working on the 3.8 is its main advantage. The 3.6 is a pain in the a** to work on. You have to take the top of the engine off just to change the plugs.