Help with preload for a ladder bar/coil over car
 

looking for help suggestions

Re: Help with preload for a ladder bar/coil over car
 

What is the issue?

Re: Help with preload for a ladder bar/coil over car
 

Re: Help with preload for a ladder bar/coil over car
 

Does it go left or right off line?

This suspension always is a struggle for me for as simple a deal
that it is!

Re: Help with preload for a ladder bar/coil over car
 

Car usually works well and leaves straight. Every so often it will tend to go right, and the rare occasion when it spins it goes to the right.

Re: Help with preload for a ladder bar/coil over car
 

if the car is working good and goes straight most of the time then I would say maybe you are out of the groove when the car goes right. There are only a couple of reasons that a ladder bar car will go left or right at the hit. first is the rear is not square in the car. Second the front holes in the ladder bar mount are worn or elongated. Check both very carefully. Typically preload is not needed if the car is set up properly. My car I ladder bar and coil over. One other thing is I don't set the car up with the shocks on it. I have some struts that I made to go where the shocks mount the same length that I run the shocks. Set it up neutral with the struts then re install the shocks and set the ride height of the shocks exactly where it was with the struts.

Re: Help with preload for a ladder bar/coil over car
 

Check that the rear is square in the car, measure circumference of slicks and compare.

Re: Help with preload for a ladder bar/coil over car
 

That's really not unusual OP, the rotation of the rear-end on low hp cars controls the dynamics of the chassis. A little pre-load takes care of that, but pre-load is a last resort. There's other avenue's besides pre-load depending on what we're working with. Do you have double adjustable coil-over shocks on the back of the car? What kind? How many clicks of adjustment?

Do you have double adjustable struts/shocks on the front? or single? or no adjustment up front?

Re: Help with preload for a ladder bar/coil over car
 

If it’s only on occasion , are both tires getting an equal burnout and heat? Out of groove like previously mentioned would make sense too.

Re: Help with preload for a ladder bar/coil over car
 

If the rear of the car has a tendency to go right on the burnout. it's wearing the left rear tire. If this is the case, this can be taken cleaned up with a shock adjustment, if we have D/A shocks in play on the car.

Re: Help with preload for a ladder bar/coil over car
 

Resisting the urge to tell you to buy something, let's start here.
Assuming everything is square, and sitting on the tires, you would want the left front bolt out, and your weight in the driver's seat.
Now you would adjust the left bar until the bolt just easily slips into the hole.
That would be zero pre-load, and where you want to start.

Re: Help with preload for a ladder bar/coil over car
 

Pretty hard to do that with a coil over car

Re: Help with preload for a ladder bar/coil over car
 

Not a bad read, a bit scholarly and maybe a bit dated as opinions, techniques and hardware has changed over time, even though the physics don't change. Also available for a more reasonable price from some other places. S&W for one, maybe others.

When chasing a problem and/or something has changed in the car, first look at the parts. How old are the shocks and springs, tires, rod ends. I've seen guys with cheap 10 year old SA shocks, beat up and leaking, dead springs and/or a bent housing, complaining that they can't adjust an issue out of the car. Verify the condition of the parts and pieces and/or update accordingly. This should be part of the regular schedule.

Weigh the car, 4 corners. Know where the weight is and what the preload (or lack of it) is. Keep track of it. If it moves around a bunch, something has worn out or bent. Good DA shocks are a necessity on a ladder bar car with decent power.

There are different ways to adjust the weights beside preload, but I would verify and baseline everything, then let the car tell you what it wants from there. Video and playback (30 fps min.) is valuable as well.

Re: Help with preload for a ladder bar/coil over car
 

Good point, Mike..I keep forgetting that S/S cars are steadily becoming GT car under the skin.

Re: Help with preload for a ladder bar/coil over car
 

Quick and dirty way to check preload (assuming you don't own scales): park the car on a flat floor, load weight into the driver seat to simulate driver weight, locate floor jack under rearend center section and slowly start jacking the rearend up. If you see the right or left tire raising first, you have preload on the other side. If you see the left rear tire clear the floor before the right side, you're likely going to be having problems.

Re: Help with preload for a ladder bar/coil over car
 

This way works perfect for me.I do mine on my full deck open trailer and it’ll go straight as a string