131 0311 Ult 09 Z - Photo 9041920

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The ram we got from POS has a 2 1/2-inch bore and a 1 1/2-inch-through hardened chrome shaft and looks like it belongs on a tractor. With an 8-inch stroke, we should have enough throw for quite a bit of rear steering, definitely more than on the GM-equipped trucks we tested in the past.

131 0311 ult 01 z

131 0311 ult 01 z

Our Avalanche is pushed around by an 8.1L engine, but the exhaust made it sound like 49.6 cubic inches rather than 496. While we were in Santa Rosa, California, we visited the headquarters of Flowmaster Exhaust to put some rumble in our jumble. It seems that many OE exhaust systems these days have the efficiency and flow just about perfect, but the sound leaves quite a bit to be desired. Lee Thompson from Flowmaster quickly had our old tubes torn out with the help of a plasma cutter and a Sawzall.

Our stock exhaust sent the fumes on a wild goose chase through the baffles of the muffler (top), and in turn muffled every grunt the engine made. The Flowmaster 50 series muffler (bottom) has dual 3-inch inputs and a single 3 1/2-inch output, plus a more direct flow to get the gases and some more sound out.

The tailpipe was one of Flowmaster's four-piece universal kits and went together with a small bit of cutting and welding. The installation tucked the exhaust up nice and neat to clear the rear suspension and then capped the end with a shiny 4-inch chrome tip, so we could be cool like all the kids these days in Hondas. Did you hear the one about how our lug nuts have more torque than import cars?

We headed to KC Customs for a paint job. Bryan Kinney had our truck cleaned with lacquer thinner and grease remover and taped off in just a few hours. This was followed by a wet sanding with 800-grit paper and then another cleaning. You may wonder why a wheeling truck should have a good paint job, and our only answer is identity. Paint doesn't make a truck perform better, but it does make a rig stand out and can give it personality. Here is a tip for you guys trying to get in the magazine--bright colors usually show up better on film than blacks, browns, and darker shades.

With the tape removed, Kinney grabbed his airbrush to give the silver scallops some extra kick. With some simple details and slight shadows, the new design seems to jump off the red background. Some light buffing followed this and within 24 hours we were done. It was pretty amazing how quickly Kinney and his crew worked, plus they had helped us out by convincing Santa Rosa Chevrolet to lend us a car during the paint and rollcage work.

A few months back we showed you these billet aluminum fuel doors from Amp Research in our New Products section. Though we usually hate shiny things, these caught our eye. Again, no better performance, but hopefully it will make us look a little bit cooler.

In order to make our 130-inch wheelbase steer like 100 inches, we took a lesson from GM and had a custom rear-steer Dana 60 axle built by Dynatrac. For strength, we installed the CTM axleshafts and U-joints. But what's really tricky is steering that axle around obstacles. For this we contacted Performance Off-Road Systems (POS) about a double-ended ram and mounting setup. But first we mounted a bridge over the rear differential made of 1 3/4-inch tubing with a 0.120 wall thickness.

The ram we got from POS has a 2 1/2-inch bore and a 1 1/2-inch-through hardened chrome shaft and looks like it belongs on a tractor. With an 8-inch stroke, we should have enough throw for quite a bit of rear steering, definitely more than on the GM-equipped trucks we tested in the past.

First we mocked up the exact location of the ram so as to not block the differential cover and still be within reach of the Dynatrac high-steer arms. Though the ram usually comes with either steel or aluminum brackets for mounting, ours were not ready yet, so we improvised with a steel clamp and some gussets.

On the ends of the ram are two CNC-machined 4140 chromoly clevises for attaching to the mini-tie-rods via some 3/4-inch-shank by 5/8-inch-bore rod ends. We attached them with Loctite and made sure they were perfectly level with each other.

Making the rear wheels return to center quickly so we can continue down the trail is very important, so we contacted Staz Works Extreme Off-Road about its return-to-center setup. The kit includes a pump, a hydraulic manifold, a control module, some switches and wiring, a sensing ram, and a joystick. Our first step was mounting the pump so that it would be protected and out of the way. We mounted it under the bed, aft of the rear axle on a steel platform, and cut a hole in the floor of the bed to be able to fill the hydraulic fluid tank.

The manifold is what controls the direction of the hydraulic fluid flow, and thus pushes the ram in different directions.

We mounted this above the passenger-side shock on another fabricated platform. The plumbing from the pump to the manifold and then to the ram was done with hoses and connectors from Orme Brothers, who can supply hosing and fittings for many different motorsports.

Next we mounted the sensing ram. This piece tells the system where the hydraulic ram is during the stroke and also recognizes when the ram is centered. In addition, ours was fitted with sensors to light small LEDs on the dash to keep us informed on the direction of the tires.

The Staz Works setup is an electrical controller within the cab going to a hydraulic system under the vehicle. This helps protect against any hydraulic leaks within the cabin of the rig, though on most 4x4s using a custom rear steer, this is probably not a concern. The control switches and joystick were mounted on a custom steel platform in the center console. To arm the system, you first switch the main power aircraft switch that energizes the pump, and then steer with the joystick. The return-to-center single-push switch and the aircraft safety switch are both made by K-Four Switches. The LED lights installed in the dash tell the driver which direction the front of the rear tires are pointed.

Another great place to find supplies for our trip was Extreme Outback Products. We rounded up a Black Rat Towing Kit and some winch extension straps, as well as some thick winching gloves and a set of No Loss valve-stem caps. However, one of the best things that we found was the Outback Sleeping Pad, which we used on our night of camping. Never before have we had such a comfortable night's rest while camping--it was better than some of the hotels we have stayed at.

In addition to the camping and recovery supplies, we also got a set of tire pliers and spoons from Outback Extreme Products, and an Extreme Aire Severe Duty Compressor. This 12-volt compressor has a 3/4hp fan-cooled motor that produces 150psi working pressure. We also mounted a reserve tank under the bed of the truck and mounted the compressor itself within one of the side compartments on the Avalanche's bed.

Our Ultimate Adventure Trip is sponsored by BFGoodrich, and we have been bugging them for a bigger tire. The crown jewel for the Avalanche has got to be our 39x13.5-inch Krawler T/AKX tires. These tires are not yet available, but we were assured that they would be coming eventually. BFGoodrich let us be the guinea pigs with this prototype tire, and we are really excited about them. The fact is that these tires were designed first and foremost for the off-road market, with road handling abilities as an afterthought. But don't get us wrong--we can vouch that driving across country on them at excessive highway speeds was never a problem. Our tires were mounted on cast-aluminum 17-inch Walker Evans Racing Beadlocks. With years of desert racing and rockcrawling experience, the Walker Evans team knows how to make a seriously strong wheel.

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