What broke:
If you think building a rally car is a lot of work, you should try maintaining one. Consider this running list of battle damage fair warning.
The First Body Damage
Event: Rim of the World 2002
Solution: Try not to crash
Technically, the first body damage happened when John Thawley, Sr., author of the Datsun geek's bible "How to hot-rod and race your Datsun 510," stopped over to buy the rally beater's old engine and immediately backed his truck into the Spec-V's front bumper. Being a bumper, all it did was move some paint.
The first real rally damage was from almost as innocuous a source. A simple metal post used to delineate the short spectator-friendly Stage 1 of Rim of the World. Bouncing around with no front shocks, I plowed right over it.
Injector Sub-harness
Event: Rim of the World 2002 and Gorman Ridge 2002
Solution: Zip Ties
Maybe it's the pre-production wiring harness, maybe it's the lack of balance shafts, maybe it's all those jumps. For whatever reason, the injector harness keeps breaking about 0.25 inch from the injectors. This, it turns out, is really bad for power. What we have learned, however, is that a QR25DE on three cylinders sounds just like a Subaru, and on two cylinders, it sounds just like a Harley.
The quick and dirty solution is one, a new harness; and two, zip tying that harness securely to the fuel rail to prevent any further vibration and hopefully any further metal fatigue in those little wires.
The longer term solution is to find some ICBM wire and make a bomb-proof harness.
We were running on three cylinders and I didn't know why. We had been passed by five cars on one stage. The bouncing from our blown front struts was making me sick. Attrition had claimed one of our competitors, but it was not going to take out the whole field. The more we raced, the more damage we would have to repair. My pride said we had to finish the stage, but after that we would retire.
Then, within sight of the finish, on the last bump of what would have been the last stage, BAM!
My first thought was, "I didn't hit anything. Why is the front of my car smashed?"
Then I remembered my prediction from earlier that day. "I'll probably put a strut through the hood today," I had said.
Glad I didn't get that carbon-fiber hood I had been dreaming of.
Shock Suey
Event: Rim of the World 2002
Solution: Billet pistons
Most experiments end in failure. This is a perfect example. Progress Technology wanted to see if its street and road racing shocks could be adapted for rally use, so the first experiment was to simply re-valve some road racing struts and see what happened. We expected them to overheat and fade (they did), we thought perhaps they might bend (they didn't), but we never expected this. Never before on any street or road racing application has a piston broken in a Progress shock. In the first four stages of Rim of the World, we had broken two.
When the pistons break, the damping goes away, and when the damping goes away, the car starts jumping off the ground whenever it hits a bump. After a few dozen miles like this, what's left of the piston will eventually get ripped right off the end of the shaft. That's when the shaft pops out the top of the strut, misses the hole on the way down, and BAM, goes through the hood.
The solution: New billet pistons with Delrin rings look indestructible so far, and allow more damping than the old pistons. The fade was eliminated with a simple high-pressure nitrogen charge that raised the boiling point of the shock oil. So far the redesigned Progress shocks are working brilliantly.
Teflon Be Gone
Event: Rim of the World 2002
Solution: all-metal spherical bearings
The same first four stages that destroyed our front struts also wore out the spherical bearings in our Ground Control camber plates. Widely regarded as the best road racing camber plates available, they nonetheless couldn't handle rallying. The spherical bearing that holds the top of the strut is rated to handle a 7,000-lb load, but the constant pounding of rough roads is apparently worse than the weight of a mere Ford Excursion. These bearings have a thin Teflon lining for durability and reduced noise, but the pounding pushed the lining out, leaving the bearing loose and noisy. Despite the missing lining, the bearings never failed, but they did lose precision and make an incredible racket. For a solution, Ground Control pressed in all-metal aerospace bearings. These are slightly tighter and make a bit more noise, but they're holding up well.
Skidplate Damage
Event: Gorman Ridge 2002
Solution: Slow down
Adding material, cutting and bending charges, this skidplate costs about $100. That's a lot cheaper than all the parts that would have broken had it not been there. The material came from a scrap heap, so the alloy is unknown. Clearly, it is too soft. The material--6061--is very difficult to bend, making fabrication a challenge, but that same property makes it a far better skidplate material than whatever this was. For the brutal southwestern rallies, a 1/4-inch to 3/8-inch plate will be necessary. This one only lasted one and a half rallies.