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LS JK: 2009 Jeep Wrangler Unlimited Rubicon

Posted in Features on July 1, 2012
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It's no secret that JK Wranglers are underpowered. Even the 2012s, while better than earlier JKs, aren't great. Wranglers scream for V-8 power and torque, and the aftermarket answered with Chrysler Hemi swaps, as the Hemi mills and transmissions worked with the JK's CANbus. The HEMIs worked well, but those who liked GM power weren't invited to the party.

GM fans, it's party time! The crew at Motech in Las Vegas, Nevada, has cracked the code and are installing GM LS-series aluminum block V-8s, along with 6L80 (or, 4L60/65/70) transmissions into JK Wranglers. The powerplants integrate seamlessly with the JK's CANbus and there are no warning lights or issues. The cruise control and GM Tap Shift shifter also work fine in the Wrangler. Motech informs us that they now use the 2012 JK paddle shifter to shift the six-speed 6L80.

Motech brought two of their JK Unlimiteds here so we could drive and photograph them. When thinking about that day, the word that comes to mind is “Wow!” Anyone who has driven GM vehicles equipped with V-8s knows how well they work. Remember when we used to put the General's mills in our Jeeps? Remember how well they worked, with two to three times the horsepower yet still returning better fuel economy than stock? Those days are back. The Motech 5.3L- and 6.2L-equipped JK Wrangler Unlimiteds work the way JK Wranglers always should have. They both had plenty of off-idle torque and screamed at higher RPM. The power delivery through the 6L80 six-speed automatics was smooth and immediate. The 6L80 features a low 4.027 first gear and two overdrives, 0.852 fifth gear and 0.667 sixth gear. There is never a time when you can't find the right gear.

The Motech JKs returned great fuel economy, too. The aluminum block 5.3L JK is otherwise stock and regularly returns an average of 20 mpg. The 6.2L LS3 Jeep had just been modified with a complete complement of MetalCloak suspension, armor, and 35-inch Goodyear tires. On its shakedown cruise to the photo shoot in Southern Utah and back to Las Vegas, it averaged 16 mpg. Not bad, especially considering our stock 2012 JK Wrangler Unlimited Rubicon with 3.6L VVT V-6 is averaging around 14 mpg.

We've always been wary of the Wrangler's TIPM, Wireless Module, and PCM. If any of them fail (and they do), our JKs are dead, dead, dead. So might we be if we're too far from civilization. The Motech GM LS V-8s are stand-alone and run even if the OE electronics fail. Those of us who worry about these things can finally have peace-of-mind.

Motech LS swaps look OE as almost all the parts are OE from either Chrysler or GM. The V-8s run cool, no matter how hot the day. The LS-series aluminum block V-8s weigh just a few pounds more than the Jeep cast iron block 3.8L V-6, so there are no suspension problems created by a heavier mill up front. VVT and AFM are supported.

Motech can perform a turnkey swap at its shop in Las Vegas, Nevada, or sell itsr Basic Builder’s Kit so you can do it yourself. The kit includes a GM E38 computer, MoTech’s JK to LS wiring harness with power distribution center (PDC) that supports AFM/DOD and VVT engines, ECM and PDC mount, emissions kit, aluminum coolant recovery bottle, Motech frame brackets that work with GM hydraulic motor mounts, alternator mount, power steering mount, AC mount, and lots more.

Check out the photos and captions for more information on this, their first 6.2L LS3 JK. Motech has done it. They've put reliable, awesome GM LS V-8 power into the JK Wrangler. GM powertrain lovers can finally come to the party — and be the life of that party!

PhotosView Slideshow

Vehicle: 2009 Jeep Wrangler Unlimited Rubicon
Owner/Hometown: Motech/Las Vegas, Nevada
Engine: GM 6.2L aluminum block LS3 V-8
Induction: MPFI
Transmission: GM 6L80 six-speed automatic
Transfer case/low range ratio: Jeep NVG241J/2.72:1
Front end: Jeep Rubicon 44
Rear end: Jeep Rubicon 44
Ring and Pinion: 4.10:1
Front Differential: Jeep Rubicon Tru-Lok E-locker
Rear Differential: Jeep Rubicon Tru-Lok E-locker
Suspension: MetalCloak 3.5-inch with 6Pak shock absorbers
Tires: LT315/70R17 Goodyear Wrangler DuraTrac
Wheels: 17x8.5 Raceline Monster Beadlock

PhotosView Slideshow


Las Vegas, NV 89145

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