[jhein]

Originally Posted by b-man

Drag or street.

Pick one.

For my Tempest I decided turning corners would be the focus of the build.

18x9 all around with 245/40 and 275/40 tires, will switch the fronts to 245/45 next time.

Previously ran 17x8 steel wheels with 235/45 tires all around. Very nice handling and fun to drive, the short 25.3” tires worked well with the 2.56 rear end and somewhat limited room up front (wheels could have used a little more backspace).

Yes, maybe I'm trying to have it both ways. As you previously said, I'm more of a "canyon carver". So if I had to pick just one, cornering would be it. Do you think the Caltracs would have any adverse effects on that type of driving?

Your car looks great with either set of wheels on it. Maybe I'm weird but when I see those big wheels on 2nd gen F bodies, most of them just don't look good to me. It's the combination of the thin sidewall and how well it fills the opening. Also wondering about ride quality. As Formulabruce points out with a stock suspension it can be harsh. How do those feel to you?

[JLMounce]

Originally Posted by jhein

Yes, maybe I'm trying to have it both ways. As you previously said, I'm more of a "canyon carver". So if I had to pick just one, cornering would be it. Do you think the Caltracs would have any adverse effects on that type of driving?

Your car looks great with either set of wheels on it. Maybe I'm weird but when I see those big wheels on 2nd gen F bodies, most of them just don't look good to me. It's the combination of the thin sidewall and how well it fills the opening. Also wondering about ride quality. As Formulabruce points out with a stock suspension it can be harsh. How do those feel to you?

Cal-Tracs change the angle at which force is applied to the front spring eye. As power is applied and the pinion starts to climb the ring gear, that force is sent through the cal-trac bar upwards towards the spring mount. This creates separation in the chassis from the suspension, pushing the tires into the ground. It straightens the leaf instead of the minor amount of tilt going on, so as the car is leaning into a corner, you're actually picking up the inside tire. Basically it creates a lot of bind which initially creates understeer as your losing contact patch on the inside tire, then you reach a point where there's too much bind, the suspension unloads and you have snap oversteer.

It's important to note that this happens with leaf springs naturally. Because they are also an axle locator, they tend not to want to tilt. They do a minor amount due to compressibility of the bushings, flex in the shackles as well as in the leaf itself. It's not a lot though and as you take up that bit of tolerance, you get a rising spring rate and an axle that is picking up the inside tire. The CalTrac makes it worse.

It's also why in many situations, leaf sprung cars don't run rear sway bars unless the springs are very soft or there is a very wide and sticky tire in the back.

The CalTrac is of course adjustable and as the lower bar is leveled, it's effect is less. You could of course try a set and play around with them. You could leave them in their least effective state for most street driving and canyon carving, then drop the bar if you know you want to play around with hard acceleration runs.

Really, the cure where leaf springs are concerned here is a leaf that can support the power you're making. You probably need more than a 200 lb rate and the leaf pack should be built so that the second leaf in the pack extends all the way to the eye and is banded there to help control spring wrap. It's probably gonna ride incredibly stiff though.

Edit: An idea I've had in my head is to run a split mono leaf which a heavy enough front section to keep up with the amount of power and of course the lighter rear section to help with ride quality. This type of setup sucks as an axle locator though, so I would employ a watts link to take care of that. That's all theory though and I have no idea how that might actually play out. Considering the cost of a good split mono leaf and a watts, I'm not sure it's anything I'll ever try.