After years of collecting parts, wrenching, procrastination, miscellaneous sidetrack projects, and other distractions we finally finished our Garage Project GPW. The most tedious part of any frame-up build is the plumbing, wiring, and all the finishing detail work. The same was true of our flatfender.
Fortunately, at least part of that was simplified for us with the use of a Team 208 Motorsports engine wiring harness and computer that were designed, built, and tuned specifically for the swapped-in ’02 4.3L GM V-6 under our GPW’s hood. The company had us take several measurements and asked us many questions about exactly what we wanted before creating the engine harness and programming the factory GM computer for us.
The result was a simple plug-and-play system that allowed the engine to start right up on the first try. Even though our 4.3L is stock, the company also specializes in wiring and proper tuning for high-horse engines via Wi-Fi as well as complete power packages. The rest of the finishing touches came together in good time, and the GPW only had a few minor hiccups on its maiden voyage. For more on that, check out the “How Does It All Work?” sidebar. Don’t forget to check out the first startup video at jpmagazine.com. Also, if you’re wondering, yes, we plan to paint the windshield frame. We simply got distracted again. However, Dr. Frankenstein would be exclaiming, “It’s alive!”
How Does It All Work?We built this GPW using knowledge and experience we gained from building several different flatfender Jeeps and other 4x4s over the last two decades. As with any project, they are never actually “done.” We feel that there are still some things that could be changed or upgraded. The 4.3L V-6 turned out to be the right choice for us. The V-8s we have used in the past were simply too heavy and too much engine to take advantage of the lightweight and nimble flattie chassis. Still, fitting the drivetrain and installing an in-frame exhaust cleanly takes a lot of planning. There isn’t a lot of space to work with. A T-18 transmission might have been a better choice than the SM420 we used. Of course, we were able to fit the SM420, but everything is very tight under there. The Headshield Products Lava Tube and Heatshield Armor made routing the exhaust possible without cooking the nearby wiring and other vitals.
Our first romp in 90-100–degree desert temps resulted in the engine running at 210-220 degrees, which is warmer than we prefer. We’ve opted to upgrade our smallish 960 cfm Spal 14-inch electric fan with a more powerful Spal fan (part number VA08-AP71/LL-53A), which draws more than twice the airflow. We also replaced the stock 195-degree coolant thermostat with a 180-degree piece. If these changes don’t help, we may have Team 208 Motorsports reprogram the fan via Wi-Fi and the OBDII port in the wiring harness. The fan currently kicks on at about 210 degrees and off at about 190 degrees. A kick on at 195 and a kick off at 180 might be a better setup for our desert Jeep.
Our brakes have been working great. However, the combination of parts that we used for our hydraulic clutch resulted in a heavy pedal. We may dive back in and upgrade to a complete CNC, Tilton, or Wilwood pedal and master cylinder assembly with a 3/4-inch clutch master cylinder to solve the problem.
The coilover radius arm suspension rides smooth over rough surfaces. As expected, the Land Rover radius arms and 10-inch-travel Fox coilover shocks don’t allow a ridiculous amount of suspension flex. The Jeep will lift tires on extremely jumbled sections of trail, but the Eaton ELockers front and rear keep it moving forward. If you are looking for an RTI ramp champ, you’ll be better off with a four-link suspension. However, the radius arms allow the Jeep to handle twisty, high-speed on- and off-road sections with confidence. Our GPW suspension handles like a four-link suspension Jeep with heavy sway bars.
The 3- to 4-turn steering boxes found on most Jeeps are adequate in most applications, but we wanted a faster steering system on this Jeep. Adding the 2:1 Howe Racing Stealth HD steering quickener was the right choice for us. Combined with the 2.5-turn Camaro steering box, it makes the Jeep drive and handle like a go-kart, which is not something everyone likes. Our current aftermarket 5.5-inch crank pulley is underdriving the OE GM 6.5-inch power steering pulley, making the steering feel a little heavy at lower rpm. We may better match the shaft rotation speed of our stock GM power steering pump to the crankshaft with a smaller aftermarket power steering pump pulley from PSC Motorsports, which would provide something closer to a 1:1 crank/pump ratio. Making this switch should improve steering assist in the rocks at lower rpm without affecting the high-speed steering feel.