RamblinChet,
I appreciate your experience in the racing world, but I'm not sure how extensively it translates to the world of slide-in campers. Certainly, increasing the rear spring rate or roll stiffness on a car without doing anything else will increase understeer—I've experienced the effects myself on a Porsche 911 and a BMW 2002. But doing so on a pickup truck on which you've just plopped a 1,000-2,000-pound camper is a different matter. Even on a 3/4-ton pickup doing so is going to alter the balance built-in at the factory to some extent. The majority of the camper weight is going to be over the rear wheels, so it only makes sense that there is where the majority of the alterations need to be done. It's easy to suggest buying a truck that has "been engineered to carry your particular load on a regular basis," but the fact is that few trucks are actually made to do so on a
regular basis, and since camper weight goes up with size, even the balance of an F250 will be altered if you put a 2,000-pound camper on it. Much less a Tacoma and a 1,000-pound camper. Not everyone wants or can afford an F350.
In my own most recent example, we put a Four Wheel Camper on our 2012 Tacoma. I added Boss air bags to the stock rear springs, and adjustable Boss shocks—thus allowing us to adjust the ride height, spring rate, and shock rebound depending on whether the camper was on or not. I did
not do anything to the front suspension, as I consider the stock Tacoma front suspension to be far too stiff to begin with. The truck rode and handled safely with this configuration—and trust me, I tested the emergency handling when a car pulled out in front of me on a two-lane highway as I was heading toward it at 60 mph, and I had to swerve hard enough to break a turnbuckle and stress-crack the skin of the camper. I wrote about it
here. Other mid-size trucks might be different, but altering the front suspension on that truck would have been a mistake.
I recently helped a friend mount a FWC Grandby on a 3/4-ton Ram, which is rated to carry more than this weight. Nevertheless, the truck sagged in the rear enough to completely throw off the headlamp alignment. Adding slightly firmer rear springs was enough to re-balance the truck. Again we saw no need to alter the front; all we did in essence was to re-calibrate the rear roll stiffness to where it should be.
Edit: I actually thought of a race car analogy. Remember the Renault R5 Turbo, the outrageous rally car of the 1980s? Renault started with the mild-mannered, front-engined front-drive R5, ripped out the existing powerplant and instead stuck a turbo race engine in the back. They flared the rear fenders and bolted on wider wheels—and I'm willing to bet they also installed stiffer springs and shocks back there to increase rear roll stiffness.
