We build Boss Wagon 4x4 to handle any road in any weather.
By Don Sherman
[used without permission]
Photos: Aaron Kiley
Project-car fever infects the C/D offices about this time every year. There's a general abandonment of typewriters, lunch runs all the way through happy hour, and "What-if" discussions rule the proceedings. Like, "What if we bolted a Pontiac engine into a Jaguar?" Or,"What if a Cadillac could be taught some handling manners?" Once in a while these fantasies jell into an idea that's actually practical, and some of us become Project Engineers. This is more fun than Christmas. We scour the aftermarket for the latest toys, and then order up a car or a truck from some unsuspecting manufacturer for "extended testing." Once it's in our hands, we rip it limb from transaxle to try out our ideas. Of course, we always put the pieces back together, usually with honest-to-Albert improvements. Sometimes we worry about safety, emissions standards, and fuel economy just like a real manufacturer, and sometimes we don't. When you're in the magazine business and building cars for fun rather than profit, you can do whatever you like under the guise of basic research.
Over the years, we've learned a couple of unshakable truths about these projects. The silk-purse-from-a-sow's-ear rule is inviolable: a Pinto will never be a Porsche no matter how determinedly it's re-engineered. Simple touches are usually the most rewarding, so we gave up trying to reinvent the wheel eons ago. And even though we're convinced that turbocharging is the only righteous path toward power and efficiency, it's quite possible to build a nifty project without a blower motor.
The whole idea is to take a good car and make it better. Which is exactly why we picked an AMC Eagle for this year's engineering endeavor. It has the most sophisticated powertrain Detroit has yet conceived: a full-time four-wheel-drive system that's smooth, quiet, and compact enough to work in a car. The car itself is plain, old, Sixties-vintage AMC. Hardly what you'd call state-of-the-art coachwork, but bursting with potential.
So we started with the order book. Some of us had hot Boss Wagon flashes the instant we saw an Eagle trimmed in AMC'S five-door (alias Sportabout) body style, so we never gave the two- or the four-door version much more than a passing glance. The Sport option bought a few pieces of blackout trim, a pair of Marchal driving lights, and Goodyear Tiempo tires. The heavy-duty-suspension and trailer-towing packages were irresistible at $147 for the pair. And just to keep things comfy year-round, we checked off a few power assists and the factory air-conditioning option. What we didn't expect was the extra "surprise" selections made by AMC's press department: the world's ugliest roof rack and a really nifty electric clock screaming "QUARTZ" from the tachometer's usual slot.
In stock form, this soon-to-be Project Eagle was our February road-test Eagle. Once all the staff's rave reviews were set to print, a couple of us blasted off cross-country with the beast to ponder its fate. That was when the Grand Plan came to mind - namely, to shift this Eagle as far as possible in the Jensen Interceptor FF direction. (In case it's slipped your mind, the late, great Jensen factory in England once built a four-place GT car with a big Chrysler engine under the hood and a Ferguson four-wheel-drive system a lot like the Eagle's.) The goal we picked for the Eagle was high-speed competency on any road, in any weather. The words "on" and "road" are far more important than "high" and "speed" in this context. What we didn't want was a Baja buggy in the usual four-wheel-drive, beat-rocks-back-into-the-earth tradition. Mr. Davis has a CJ-7 for that. And the high speed we're talking about is relative. Even the double-nickel is pretty fast if you can hold it through a blizzard without a nervous frenzy.
Before we plunge headlong into the lengthy modifications list, you should realize we did leave a few things alone. Namely, the whole powertrain, from spark plugs to spider gears. Althoughwe'd love to feel the persuasive pull of a small-block V-8 under the hood, we didn't want to sacrifice even one of the 4.2-liter six's 16 mpg. (At least not yet. But realize that these projects have a way of drifting into Phase Two.)
In our road test, we found the Eagle's stopping ability quite impressive (195 feet from 70 mph), and it's due in no small part to the anti-lock effect of the limited-slip center differential. So wealso left the brakes alone and focused on the Eagle's one principal advantage - four-wheel traction - to make the best of it. We had two applications in mind: dry-pavement drivability (what we usually call "handling" in this book) and bad-road tractability. Ideally, our Boss Eagle would never have to ease back from good, quick progress through life for such concerns as freeway entrance ramps, mountain switchbacks, rain, snowdrifts, glare ice, and mud. What we had in mind was sort of the ultimate Postman's express.
The dry-handling part was easy. We used conventional techniques, well proven in past projects: more roll stiffness to control the natural tendency for the tall body to teeter in the turns; the biggest, stickiest tires that would lit under the fenders; and higher steering effort to feed back more road feel. The one advantage we had here and really intended to capitalize on was the Eagle's all-wheel drive. Since tractive effort is spread over four wheels instead of just two, driving forces are far less likely to screw up cornering attitudes. The suspension can be tuned race-car neutral with practically no chance of an embarrassing spin-out, even if the office gopher lifts off the gas and jumps on the brake at the wrong time on a flat-out run to the post office.
Quickor Engineering supplied the largest sway bar it makes for the front- a meaty 1.125-inch job - and three bars to choose from for the rear. We base-lined the car in stock trim on a 200-foot skidpad and a 600-foot slalom course, and then tried the big front bar in combination with the biggest of the three rear bars (0.875-inch diameter). In stock form, the Eagle plowed like a John Deere and tipped like the Titanic. The maximum cornering traction was 0.70g. The Quickor bars boosted skidpad speed to 0.73g, flattened out most of the body roll, and did a better job of distributing the cornering work over all four tires. Transient responsiveness was also improved. The Eagle's slalom-course speed was 42.4 mph, compared with 41.5 mph stock. We saw no chance of improving the situation with less rear roll stiffness, so we stopped tuning while we were ahead.
Once the chassis was under control, we attacked the steering system. The Eagle uses a steering gear supplied by GM's Saginaw division that just happens to be very similar to hardware fitted to various GM car lines. Such as the Firebird Trans Am. And to get that T/A racerlike feel through the wheel once you've got the Saginaw gear under your hood, all it takes is the right spool-valve assembly, GM part number 7832057. The key difference is a stiffer torsion bar that sends a lot more road feel through before the power assist takes over. One presto-changeo operation on the garage floor, and the Eagle had true sports-car steering sensitivity.
This was where we reached a fork in the development path. For ultimate dry handling, the Boss Eagle needed super-stickum, low-profile tires. For bad-road running, it needed a knobby set of mud-and-snows, the taller and skinnier the better. We compromised with the latest all-weather tires from Goodyear, which they called Arrivas. In essence, these are improved Tiempos - quiet-running on dry pavement, grippy on wet or snow-covered. In addition the Arriva represents major advances in tread life and rolling resistance, according to Goodyear; it embodies the latest thinking in steel belting, open-block tread design, and neutral-contour sidewalls. According to our test results, the Arrivas aren't quite as skidpad-sticky as Tiempos, but they definitely ride as well. We'll report on their bad-road ability at a later date, once we've logged a few weeks of nasty Michigan weather.
One modification that should keep the big bird rolling come hail, sleet, snow, or whatever is our adjustable-ride-height system. At the flick of a dashboard switch, we can raise the Eagle from its normal stance (more than seven inches of ground clearance) to an altitude where the roof snags low-hanging branches. This bootstrap jacking system is simply a set of four Gabriel Hi Jacker air-shock units fed by an electric air compressor under the hood. Maximum boost is 2.6 inches in front and 3.0 inches in the rear. Stability of course suffers with elevated ride height, so this capability is.meant for low-speed extraction from snowbanks, or the occasional stream-bed crossing. It's also great for oil changes.
We hope the Eagle won't spend all its time tiptoeing through bad weather. When it's basking in the warm glow of summer staff excursions, it should look the part, so we spent some time on cosmetics. AMC's original intention of a neatly chiseled red box trimmed in black was a good one, so we kept that theme - minus most of the gingerbread that AMC baked on at the factory. We blackened all the shiny stuff, ripped off and threw away the stand-up hood medallion, the roof rack, and the hubcaps; and generally tried to wipe extraneous trappings off the exterior in the hope that good, basic proportions might have a chance to shine through. Alloy wheels don't exist for the Eagle as yet, so we modified a set originally designed for a front-drive Cadillac Seville and bolted them on.
Other than a few words from our sponsor on the front fenders, we added nothing that wasn't black. The hole in the roof is a Britax Sunliner. This electrically powered glass panel is packaged in a black "cassette" that mounts on the outside of the roof panel. The advantage over flush sunroofs is that this one doesn't sacrifice a micron of headroom. The rear third of the roof became a functional load platform after we screwed down a "Magik-Rak,'' made by Amco. Its cleverly designed stainless-steel strips accept a variety of clamping devices to lash down everything from surfboards to snow skis. The clamps can be slid anywhere along the length of the rails, they can be flipped up to act as luggage stops, and they also adapt to crossbars, bike racks, and nylon tie-down straps.
Once the exterior was properly flat-blacked, we turned our attention inside. Basically, we stripped out all the AMC early-baroque furniture and started over. Recaro subcontracted the seating work. Front buckets are N-Wide models upholstered in a special sueded vinyl. The rear seat is trimmed to match, right down to net headrests. This vinyl material feels like animal hide, grabs like Velcro, and resists soiling like iron. Just the ticket for every occasion from those sloppy hunting trips to black-tie evenings on the town.
To keep the entertainment level at a fever pitch, we selected the aforementioned hole-in-the-roof for rolling sunshine, a new Momo "Elegante" steering wheel to get a grip on driving, and enough electronic toys to fill a Hewlett-Packard catalog. The CB is a state-of-the-art CR520 remote unit by Motorola; all you see is a microphonelike device that places command over all CB functions in the palm of your hand. The audio entertainment center is a Fujitsu Ten model EP-820 Dashboard Wizard. For once, the name is no exaggeration. This miracle of modern electronics packs an AM/FM-stereo receiver, a cassette deck, a graphic equalizer, and a digital clock all in one in-dash console. It's loaded with so many seek, scan, station-memory, Dolby noise-reduction, fast-forward, and auto-reverse features that it's a party just sitting in the driveway playing the thing. The Wizard also makes some good sounds, particularly with the Fujitsu Ten model PA-150F power amplifier (twenty watts per speaker) driving a pair of Fujitsu SSB-4G65 two-way speakers in back and the original AMC door speakers in front.
For the video portion of our entertainment program, we wired in a new Zemco ZT3 Driving Computer. This is a simplified version of the Compucruise device we've used with great success in the past. The ZT3 has no cruise control, but it spits out the same speed, distance, time, and fuel-economy information (both instantaneous and averaged over a trip) as the Compucruise. The ZT3's major advantage is that it's easier to use. You can talk to it through only nine keys, while the other fourteen, which are needed only for calibration, are tucked away behind a cover panel.
All these new whiz-bang accessories looked a bit out of place in what was left of the Eagle's late-sixties interior, so we again exercised our rip-out and throw-away option. A factory tachometer plugged neatly into the clock hole. The grotesque parcel shelf was torn from its moorings and sent to the shredder. And we peeled back one particularly offensive patch of fake wood surrounding the heater controls, only to discover a tasteful 'island of textured black plastic. The final touch involved one long afternoon and a gum eraser, with which we eradicated most of those fine chrome edges that interior stylists are so fond of wrapping around every spare rectangle.
The next step is to press the Boss Eagle into service. We're eager to see if what we've wrought is actually as usable as we planned. Mr. Davis's dogs must pass judgment. Our associate editors will each take a shot at their favorite cloverleafs, while pondering, "Pinto or Porsche?" The Exec. Ed. has one of those button-punching, upholstery-scuffing daughters. And there are trailers to be towed, romance to be pursued, birds of prey to be hunted, slopes to ski, and a picnic or two on the Eagle's agenda. We'd also like to bounce our work off the AMC guys to see what they think. We'll let you know.