2007-2011 Jeep Wrangler Tuning Tricks - 4-Wheel & Off-Road Magazine

The Ford Raptor and Jeep Wrangler Rubicon proved that enthusiasts are willing to pay dealers for aftermarket-influenced performance accessories. Still, these 4x4s have some room for improvement.

The Bully Dog GT tuner is an example of a product that increases Jeep JK functionality. For Rubicon models, the GT Tuner offers additional features, such as the ability to disconnect the front sway bar on-the-fly and/or engage the lockers in all ranges at speeds up to 30 mph.

Like most tuners/engine programmers, more power is the marquee feature. For the ’07-’11 3.8L Wrangler, Bully Dog’s dyno figures claim an increase of 11.5 hp and 15.3 lb-ft on regular fuel on the 3.8L V-6. The Jeep GT also works on the JK 3.6L V-6 and Grand Cherokee/Commander 4.7L, 5.7L, and 6.1L Hemis. Bully Dog reports gains of up to 35 hp and 40 lb-ft on the 6.1L Hemi. This can help overcome the compromised power/weight ratio from running larger tires, aftermarket bumpers, and other accessories. (The Jeep GT isn’t approved for sale or use in California.)

We demo’d a Bully Dog GT on a ’10 Wrangler Rubicon JK, and the job is fairly straightforward. Our only recommendation is to update the included SD card online during business hours, particularly if you use a Mac—Bully Dog’s website downloading is optimized for PCs running newer versions of Windows.

Other than that, the instructions are straightforward but not vehicle-specific. The biggest time-consumer is pulling the power wire to a key-hot fuse in the fuse box. Also, reflashing takes a lot of battery juice. The GT will stall if the voltage drops during the reflash. Putting a charger on the battery and maintaining a minimum 20-amp boost will speed up the process.

Finally, prior to your taking the Jeep to the dealership for service or any warranty work, Bully Dog recommends returning the vehicle’s programming to stock, then unplugging and removing the GT tuner. The company claims that dealership diagnostics can tell that something has been plugging into the OBD-II port, but not that the PCM has been reflashed.

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What It Fixes

• A choice of three tuning modes. Regular/Tow mode adds a claimed 12 hp, 15 lb-ft of power on regular gas. Off-Road/Trail mode has all the power of Regular mode but with decreased throttle sensitivity to minimize wheelspin. Premium mode adds a claimed 15-plus hp and 20 lb-ft with 91-octane gas.
• Engages lockers in all transfer case ranges and any speed up to 30 mph (Rubicon models).
• Disconnects sway bars in all ranges at speeds up to 30 mph to increase articulation (Rubicon models).
• Recalibrates the speed sensor for nonstock tire diameters (up to 45 inches) and axle ratios (2.0:1 to 8.0:1).
• Rev limiter adjustment. Up to 6,200 rpm for 3.8L engines, 6,700 rpm for 3.6L V-6s.
• Idle adjust, ideal for operating alternator-driven underhood welding systems and maximizing winch performance.
• Disable traction control.
• Fan control. Turn off the engine fan for water crossings or run it in high speed at any engine temperature.
• TPMS adjustment allows expanding the acceptable range for as wide as 10 to 60 psi before the warning light comes on.
• Powertrain monitoring and specifiable warnings. Parameters include fluid temperatures and engine load.
• Read and clear Check Engine codes.
• Expandability to accept a pyrometer and O2 sensor.
• Driving Coach makes suggestions for improving fuel economy.