Does anyone have any experience with the V6 in the JK? Is it gonna be enough for the Unlimited? Do you think that Jeep will offer any LARGER engines for the Unlimited, like maybe the 4.7L V8 or the 5.7L Hemi?

I am looking forward to upgrading from my YJ to the larger JK Unlimited.

 

Yeah, it's got enough power. I've driven both the auto and 6-speed and I think you'll be happy with either. That is, at least until you install bigger tires

 

its all about gearing, I would spend the extra $50 and get 4:10's

if i was buying the unlimited.

 

I've test driven both, and the 6-speed seems a better choice to me as you can hold the gear you wish to keep the RPMs where you want them. For me, then auto was way too frustrating. Flooring it on the freeway at 65mph, I felt NOTHING!!!

As for gearing, the 4.10 is fine if you're going to stick with the stock tires. I feel, as do virtually all the off-road/Jeep magazines, that the JK is moderately underpowered. Putting 35" tires on with the stock gearing will be frustrating at best, depressing at worst. Switching the gears to 4.56s with 35" tires would keep the ratio very near stock, but just the added weight of the larger tires will slow you down some. Once I spring for the 35" tires, I plan to upgrade straight to 4.88 gears front/rear. This should still leave me plenty of power with 35" tires, and if I go to 37" tires later, I'll still be very close to stock gearing again.

Just my .02 worth!

Tom
Bryson City, NC

 

I agree with 4.88's but you only have two options when ordering. and 4.88's is not one of them..

I'm stuck on everyone saying its underpowered,,, its a jeep not a mustang.

It'll be fine with 4:10 and a 6 speed, even with 35's which i'lll be running. Your not racing, your rock crawling.trail riding or for some mall crawling.

 

Supercharger..

I am sure they will develope a kit in no time for this application..A moderate boost level such as 4 or 5 psi..Would be easy to accomplish,even with the higher compression levels in the 3.8 v6 compared to the old 4.0..

An extra 100-125 hp never hurts

 

yea i agree more power isn't a problem but it is a jeep not a race car. I mean there really is no difference in power from the jk to the tj. Personally the 4.0L would get bogged down too with larger tires if you didn't regear. So this is the same sitch ppl were in a few years ago and now. U just gotta regear and also spring for an exhaust, power tuner, if ur really dissapointed in the power. Or do like many jeepers and after a while do the 4.7L swap or something bigger. theres a thing i saw where they are going to put the 6.1 outta the srt8 into a jk unlimited

 

There are tons of V6 motors out there and I feel the V design will be easier to adapt pro mods for. Hood clearance might be an issue and so might low end power. Keeping the power low will probably be the hardest part. This style motor we will probably see way more mods for than the 4.0 because of its simularities to everything else. What doesn't come with a V6?

 

True duals might fit. Exiting right before the back tires, yeah!!!

 

mmmm thats what im talkin about! headers running into high flow cat converters into some 2 chamber flowmasters... ooohhh yeah! Soon as my lift's on im goin strait to my local performance exhaust shop and seein if they can rig me up something!