Caltracs causing separation

First time at the track with my caltracs and now I have a new issue, when I launch the rear end hikes up big time. If I stay in the throttle it finally settles down at about half track. Or before the 60ft if I let off it goes down then stays down when I get back in the gas. This has never happened on the street probably because I could never hook on the roads. I had the caltracs in the bottom hole with a little preload and the 9 way adjustables on 5. I moved it to the top hole with neutral preload (was told to try but I thought it would be worse) and set it to neutral preload (just touching springs). Did the same thing, brought it back and set the shocks to 9 and it did the same thing. That's all I was able to do then I got eliminated. Truck kept slowing down every pass. Tire pressure at 24lbs, MT ET streets.

It's my first time with caltracs, so I'm unsure which way to go. I was also told to set my pinion angle more negative (around 6-7 negative). Does anyone have experience with this sort of issue?

setting pinion angle without moving the suspension components does nothing..... i always lol when I hear people refer to pinion angle as a chassis adjustment...... piion angle keeps u joints happy is all. now if your adjusting pinion angle by way of making suspension adjustments thats different.

cal tracs dont work very well on trucks, the front weight percentage is way high.

The whole point of those bars is to create anti-squat. Post a video if you can.

Here's a pass with the bar in the top hole, neutral preload, and the shocks set on 5. Could this be happening because the weight isn't shifting to the back due to the preload on the bars?

I've been down this rd already. The caltrac geometry is out to lunch on their truck setups. Ride height GREATLY affcts the geometry. I've went from getting the back tires off the ground to lifting the front tires. You need a set of my lazer cut dropped front brackets.....

putting the bar up higher makes it worse. you want antisquat but too much aint a good thing.

the brackets dirtworker hasnmight be the ticket...... bottom bar needs to come down to take some hit out of it.

Have you taken any leafs out of the rear spring pack ?

I am running them on my fairlane and have run the SSM. Lift bars.

dirt_worker wrote:I've been down this rd already. The caltrac geometry is out to lunch on their truck setups. Ride height GREATLY affcts the geometry. I've went from getting the back tires off the ground to lifting the front tires. You need a set of my lazer cut dropped front brackets.....

Do a search on Mikes posts, He has done a ton of research and development on the caltracks, and has a good insight on what it takes to make them work, well, as best they can on a truck.

Here is a member that is running caltracs https://www.youtube.com/watch?v=Bp2iq-H3igE

I was talking to "droppedf100" and "dirt-worker" a good amount when I bought the caltracs. I thought about making something up just because I don't have the money to get new brackets right now. I was also thinking about putting extra clamps on the leafs. They are stock f100 springs and no I have not added or removed any leafs. Just did an axle flip.

I think I need a bigger gap on the caltracs to help let the weight shift back, but still, the bars aren't parallel to the ground like I hear they should be.

It's not the springs wrapping it's the inability to get the instant center where it needs to be. With a truck being so high off the ground. Did you say you had the rebound full tight on the shocks ?

IDT-572 wrote:It's not the springs wrapping it's the inability to get the instant center where it needs to be. With a truck being so high off the ground. Did you say you had the rebound full tight on the shocks ?

with 9 ways they were at 5, then I tried 9. When I tried 9 the bars were switched to the top hole. Where do I need to move the instant center? forward?

You need to plot it out on paper or call Mike, every deal is different.

Instant center is the line drawn through both leaf spring mounts and the line the caltracs makes intersecting right? I'm calling Calvert tomorrow, and probably Mike if I can.

looks just like my clunker last weekend, except the mine is 4wd with a 6" suspension lift. I've wondered what trucks, 2-wheel or otherwise, would need to work decent.

Your IC is way too short and very high. The farther out I lengthend my IC the better it worked.
Moving your shocks behind the axle would also help although that's not gonna fix the issue you're having. Either lower the front of the bar, lower the truck more, or take them off.
I'm honestly not that impressed w my caltrac as delivered from calvert. Ive actually had my best 60ft w $20 slapperbars. Only reason I switched was because of a broken pinion due to "axle wrap".

Btw.....my IC was out in front of the front bumper last time I raced and we had air under both front tires

Calvert is sending me some spring clamps, they said to clamp the rear leafs and give it a shot because they are probably (and I saw it happen before actually) opening up too much. So I'm going to try that and see what's up first.

Caltracs are meant to generate a bunch of separation to help lower torque engine combos plant the tires. Add a bunch of extra engine torque to the picture and the Caltracs really start to generate some leverage.....way too much in some cases. Then you end up trying to calm things back down with real tight rear shock extension valving settings.

As long as everything is set up right the work great. We had a car going 1.15 60's on radials with that setup but it took time to get there.