Pulling my hair out

When you say you tightened up the shock 2 clicks, what did it change? As in did it make it stiffer in bump and rebound or did it make it stiffer in one direction and looser in the other. If I could understand what change happens when you move the clicker it would be easier for my simple mind to understand.

I know Calvert says it changes both when you turn the knob but I don’t know if it’s making both directions stiffer at the same rate or what exactly happens.

My cousin bought a set of Calverts for his flaming chicken (Firebird) and he claimed he had wheel hop with a set of Caltracs.

So I had his girlfriend take some close up video of it and what was happening wasn't “wheel hop” but the tire bouncing back after the hit. He got some of it out but not all of it. Calvert told him to buy a different tire.

The tire gets hit like you are hitting it with a big hammer. The harder you hit the tire, or if you use a bigger hammer or both, the more the tire will try to push the hammer back off the tire. That’s the same thing that happens in the car. The tire is fighting back. I’m not saying that’s exactly what’s happening. Now you have another box to test to rule that part out.

This kind of thing can drive you nuts, especially when you have to go to the track to make the car do what it’s doing. That gets expensive real quick. And frustrating.

BTW, you can get to the point where the valving of the shock can’t handle the shaft speeds it’s seeing. The only fix for that is to revalve the shock or buy a different shock.

Interestingly, Dave Morgan of the “Doorslammers” chassis book either wrote an article about shock speeds, or I heard it at one of his seminars or both.

Anyway, he was tuning on a big block Camaro with a stick and ladder bars. A horrible combination to say the least. Anyway, they had a data logger on the car so they hooked a potentiometer up to the rear shocks to measure how fast the shock was coming apart at the hit. With the shock on the stiffest rebound setting, the shock came apart so fast the computer showed the shock was essentially not controlling anything.

Like I said, that is a worst case scenario but I can be rather easy to overcome a shock’s ability to dampen in either direction. And that is the shock’s job. It has to control the motion of the rear axle. The instant center sets the maximum speed the tire gets hit and the shock needs to dampen that movement so you have some ability to tune the hit, and any motion of the tire/axle trying to bounce back into the wheel well.

I’m not saying that’s your issue. Just pointing out how important the shock is. As the engine makes more power and with a short, high IC like a Caltrac or similar system that hit can be incredible and the tire just can’t deal with it.

That’s why Pro Stock has a rule that sets the MINIMUM weight for the rear axle. If the PS guys had their way, they would put more static weight on the front suspension so they could hit the tire harder with the 4 link. There is more to it than that, but that’s the simple explanation as to why that rule exists. It’s also one reason you don’t hear the PS teams screaming for aluminum blocks. They don’t want to give up that forward weight.