rack angle?

Does anyone know what the maximum allowable angle of the tie rods, fore-aft, of the rack, back to the tie rods can be?

Needs to be in the best position as to have the least amount of bumpsteer.

What Jon said.

Rack fore/aft placement has an effect on bump-steer, just like rack height does. The greater the suspension travel, the greater the effect might be of unwanted bump-steer. The rack's main body/shaft width vs the width between the lower control arm's chassis mounting points also has an effect.

Mechanically speaking, to the point the shaft (round) portion of the tie rod interferes with the ball's socket located in the rack & pinion unit ..... if that's possible! Attempt to locate the rack unit near the middle of your spindle's travel or a bit lower on a drag race car.

Dave.

Is there a point where you can actually mount it too far forward thus hindering the ability to turn the wheels? Say when the outboard wheel is turned more then the inboard and doesn't want to turn back?

jbozzelle wrote:Is there a point where you can actually mount it too far forward thus hindering the ability to turn the wheels? Say when the outboard wheel is turned more then the inboard and doesn't want to turn back?

I always thought this was one of the problems with the 71-72 Pinto front end that Morrison and Alston made. I had a quick look at their sites and Morrison doesn't have them anymore and I swear the Alston clip has moved the rack back from where it was years ago.

jasonf wrote:I always thought this was one of the problems with the 71-72 Pinto front end that Morrison and Alston made. I had a quick look at their sites and Morrison doesn't have them anymore and I swear the Alston clip has moved the rack back from where it was years ago.

If I remember correctly the Pinto & Mustang II designs had a bump-steer problem from the factory anyway. And the spindles of both having two slightly different body heights didn't help any either thus adding to the confusion for the drag & street aftermarket. It wasn't till many years later that some of the aftermarket manufactures decided to correct the problem (after they had sold tons of kits with the problem never addressed).

Some of the older Pro Stocks were really limited on engine setback amounts on the smaller body styles. So they pretty much had to really throw the racks forward to clear the oil pans regardless of what it did to the bump-steer geometry. The Yuill Brothers old Pontiac J2000 P/S had the rack so far forward that it had decent bends in each outer tie rod shaft so the rack could reach struts & still keep the ball sockets from binding. But the car didn't really work very well & was axed.

Removing suspension/steering geometry from the picture for a second, the mechanical limits for the rack's ball socket joints max rotation (before reaching a binding point) is probably going to be a little different from one rack manufacture to the next. The factory Pinto rack's ball socket joints look similar to Flaming river's, but they are not exactly the same design/construction.

The Flaming River Pinto rack pictured has a ball socket joint binding limit of about 26*-27* in any direction.