Exhausting Aspirations
Jeep Commander to the Rescue — Part 2Last month we introduced our "Commander to the Rescue" project vehicle, a brand new Jeep Commander destined for a life of high-mountain adventure with the Placer County, California Search & Rescue Team. Now when we say high-mountain adventure, we're not talking about rescuing cats out of grandma's maple tree. "Commander to the Rescue" will become an integral part of a team: one that fields calls for lost skiers, off-track mountain bikers, and whitewater rescue or recovery. That said, we had our work cut out for us to transform it from a luxo mallcruiser, to a backcountry bruiser. We left off with our initial upgrades: an adjustment in altitude and gription with a Superlift four-inch suspension and a set of ProComp All Terrains wrapped around 17x8 ProComp Extreme Alloys. This month we are enhancing its ease of aspiration and exhaust with a Airaid Quick-Fit air filter system and MagnaFlow cat-back exhaust.
There is no question that Daimler Chrysler's 5.7 liter Hemi is one of the hottest power plants to hit the industry in some time. But with the Commander weighing in at over 5000 lbs, and with fuel prices climbing, it stands to reason that more power, improved throttle response and more fuel efficiency would be at the top of the "must have" list for Commander owners. And the fact that our Project Commander will be spending most of its time in the high-country of the Sierra Nevadas, improving its ability to breath easier and expel spent gases was a natural upgrade.
The heart of AIRAID's Jeep Commander intake is the High-Flow Air Filter. In terms of filtration, the SynthaFlow™ filter is a specially blended combination of gauze and synthetic layers that consistently filter airborne contaminants down to two microns, providing superior filtration at no extra cost in terms of airflow.
The QuickFit™ system utilizes the lower portion of the factory air box, but the bulky stock plastic plenum has to go. With the upper section of factory air box, air filter and oil cap removed, the engine cover can be raised slightly to allow removal of the stock intake assembly. In the process, the wire tie holding the breather tube must be clipped and the factory temperature sensor removed.
The QuickFit™ airbox is a two-piece assembly that utilizes the hood of the vehicle as its upper barrier. Once assembled, a flexible weather strip is pressed over the upper edge to form the seal with the hood.
Carefully insert the temp sensor into the new crossover plenum. It is a tight fit and may need a little lubrication. Use water, don't use an oil based lubricant.
For starters, MagnaFlow's engineers have developed a new bolt-on cat-back exhaust for the Hemi mill. MagnaFlow's high quality stainless steel systems not only have a long reputation for looking and sounding great on the road, they also have the durability and strength to handle extreme off-road driving conditions. The mandrel bent free-flowing design, paired with MagnaFlow's straight through muffler design, reduces backpressure while providing a significant boost to horsepower and torque. The dual muffler configuration gives the Commander a "commanding" smooth tone when you stand on the skinny peddle, but keeps sound at a minimum inside the cabin.
With the AIRAID airbox and filter installed, and breather hose reconnected, the new plenum slips right in. Done deal!
Don't throw it out! The SynthaFlow™ filter is designed to be cleaned and reused. This bright yellow sticker should keep some knucklehead from tossing it in the trash, should your wife (or husband for you wheeling girls) take it to the local quick lube. AIRAID suggests cleaning it with a Filter Tune-Up kit, available from AIRAID.
Installing the AIRAID system is a breeze and can be accomplished with ordinary hand tools in under 30 minutes. In addition to enhancing aspiration, the new look cleans things up under the bonnet, and exposes the 5.7 Hemi mill.
The MagnaFlow cat-back system is another truly bolt-on application. Crafted of 2.5-inch mandrel bent tubing, the unit implements a primary muffler to stifle spent gases. A secondary unit is then used to manage tonal control and noise levels heard from the driver's seat.
AIRAID was the first company to step up to the plate with a filter system for the Commander. And given the company's track record for improving aspiration, we didn't have a problem calling them. Using its expertise with other Hemi applications, AIRAID has developed a simple, bolt-on system for the Commander that boosts horsepower, torque and improved efficiency. In addition to improving throttle response, the company states that on a dyno, the QuickFit™ air intake system generated an additional 11 horsepower and 16 foot-pounds of torque at the rear wheels.
After unbolting the stock tailpipe and disconnecting the grommet mounts, it can be removed and the MagnaFlow unit slipped in. A polished 5-inch round muffler just forward of the double-wall stainless steel tip controls final noise levels.
The OEM muffler is as big as a coffin and not much to look at. In comparison
The OEM muffler is as big as a coffin and not much to look at. In comparison
As with the stock exhaust, the MagnaFlow system uses compression fittings rather than exhaust gaskets. After hooking up the grounding strap, make sure the fore and aft sections are in fairly straight alignment as you tighten them up. All MagnaFlow stainless steel exhaust components are manufactured to ISO9001 quality standards and include MagnaFlow's lifetime warranty.
For the next few stages of "Commander to the Rescue," we've summoned the assistance of Wyotech Automotive Institute, a leader in providing quality technicians to the automotive industry. Scott Swafford, Chassis Fabrication and Street Rod Coordinator for Wyotech's West Sacramento facility, instructor Nate Sanso, and their current team of chassis-fab students, will be handling a large chunk of the work from here. In addition to the Magnaflow and AIRAID enhancements, they will be assisting in a slew of other upgrades.
Follow up from last month: Do as we say, not as we do! We had several issues with last month's installs. During heavy acceleration, we had some driveline contact with the exhaust and cross member. The fix: Had the muffler shop lower the exhaust just ahead of the forward cat, then we took a grinder to the crossmember.
Due to the flexible nature of the differential mounts, the exhaust mods will most likely be required. And we need to restate the importance of the crossmember support bracket, provided with the Superlift kit, it must be fully seated on the lower horizontal surface of the crossmember to avoid contact with the driveline. Our bad. Lastly, the tire pressure sensor warning light blazed brightly on instrument panel after installing our ProComp wheels. The fix: We didn't install one of the sensors. Duuh!.
What's next? Our fabrication team goes crazy with chop saws and welders as "Commander to the Rescue" goes under the knife. Stay tuned while we scrap the shiny stock bumpers for some serious body armor, rock sliders and a Warn Winch.
From its beginnings in a 9,000 square foot building in 1966, Wyotech's Laramie Wyoming (hence the name) is now comprised of over 298,000 square feet of shop, classroom and administrative facilities. Add that to a comprehensive curriculum the fact that they have seven such campuses, and that puts them at the leading edge of automotive training institutes in the country. Some of Wyotech's grads include Spike TV's Xtreme 4x4 show co-host Jessie Combs.
SOURCES
Jeep Commander
www.jeep.com
Pro Comp Tires & Wheel
www.procomptires.com
Superlift
www.superlift.com
Magnaflow
www.magnaflow.com
AIRAID
www.airaid.com
Wyotech Institure
www.wyotech.edu
Next month: Due to the fact that the Commander is so new that no one makes body armor and skid plates yet, the Wyotech guys will be put to the task of designing and fabricating a winch-mount bumper, belly protection and rock sliders from scratch.