Fellas - just daydreaming about potential winter projects. I'd like to have my steering box rebuilt to a more responsive ratio- likely using one of the services I saw mentioned here instead of a total swap. I'd thinking of going with the lowest ratio they'd install, I think its a 12 or 12.5:1. Anyone have any experience with making that ratio variable? Would it effectively reduce the responsiveness of the new ratio? Or would it help just make straight line cruising more forgiving.... I likely won't be auto crossing anytime soon. Rather I like to make mods to the car that modernize the feel and performance from a sportier perspective. How's that for a poorly described auto upgrade genre? Let me know your thougts - thanks....

I have a 12.5 straight ratio and have no issues with general straight line cruise at all. Personally I would not bother with a variable ratio box.

The one thing I *would* change about my box is to have the largest torsion bar they make to increase the steering feel/effort a bit. As it is now it has the traditional over boosted too easy feel to it.

I had a 69 variable ratio box rebuilt and ran it for about 2,000 miles. Had no problem, and had just the correct road feel for me (steering effort). Was rebuilt by Harrys Steering in Frager Mi. No I don't know the T-bar size in this bo after rebuild. I purchased a Grand Cherokee box 82-89 12.1 fast ratio box low milage, from a wrecking yard. This box is fast and also very low effort. Not much road fell if any. At hwy. speed. Dont sneeze or reach for anything in the seat next to you or you may endup 1/2 way into the next lane. Around town or at any low speed its great.
Acording to Jim Shea, retired engineer from Saginaw, his charts shows that the Grand Cherokee box has a steering effort of 20-26 with a T-bar of 0.195.
His list of boxs also shows the 1969 variable ratio 16-12.4-1 with a steering effort of 15-21 with a T-bar of 0.175.
I don't know how these steering efforts measurments are obtained, but I have to guess this is in the vechicle loaded on the road surface and running. The Cherokee has the (large) the large stock 31 inch 245-70-16 tires from the factory.
I am running a rebuilt older style Chevelle power steering pump with the newer preasure relief valve that was used from 1970, about 1400 psi.. Tires on the Chevelle are 225/60/15. Car 1965 El Camino was orginaly manual steering. All front end components have been repaced with new components.
Just my $.02.

Fast???

Well my daily driver is a rack and pinion Mustang GT so my idea of fast steering might be a little biased ;-) I know driving our Honda Odyssey van can drive me nuts because it steers slower than I am used to. I seem to have to make unsettling corner steering corrections for a few hundred miles until I get recalibrated.

I don't think I would ever describe the steering on anything as long as an El Camino as fast.

It has the same steering feel or turning effort at speed as it does 5 mph. Except at speed, 70 mph, your moving at about 100 ft. per sec. No difference in steering effort. At least in my car. I am thinking of swaping the varailable ratio box back on. I sure would like to know what NASCAR steering ratios are in the medium length tracks, like one mile one.
Anyone.

The more I drive it the more I feel like home. Just a quicker wheel than any of my last 6 cars. But just like my 1999 Grand Cherokee, it uses a different steering box.

Very true, there is no speed sensing or feedback as there is on some of the power rack and pinion systems. But part of this is the front end suspension geometry. Put about 4* of positive caster in and it will get much more stable at speed. Of course it takes some special parts to get that much caster in an old A-body, but it can be done.

The valve efforts that I quoted are obtained with the gear fixtured on a test stand. It is not obtained with the gear in a car. However, it is a good comparison measure of one gear valve versus another. I am surprised that the Jeep Grand Cherokee 12.7:1 gear seems to have light effort complaints because the valve specs would indicate that it has moderate effort. They use a 0.195 diameter torsion bar in the valve. (The larger the bar diameter the heavier the effort.)

Most of the Caprice 12.7:1 police car and handling gears actually have lighter effort valves than the Jeep gears. Most Caprice gears have 0.185 diameter torsion bars. However, I don't hear light effort complaints with those gears.

BTW, the quoted torsion bar diameter is the measure of the diameter of the necked down portion of the bar inside the valve. You cannot get to the bar to measure it without destroying the valve.

JIML82

PS: The real problem with the Saginaw variable ratio (VR) gears is that they were designed strictly to reduce the number of handwheel turns (full lock to full lock.) They do that by speeding up the ratio as you approach full lock. However, the on-center (straight down the road) ratio is typically 16:1. This is just a bit faster than the late 60s Chevelle power gear ratio of 17.5:1. So I wouldn't expect to get much of a crisp, responsive feel on center from a Saginaw VR gear.

vroom3440,
after installing the 500in. lbs. front springs and the tall ball joint with the stock height chevelle disk spindles and the SC+C adjustable upper control arms the front is adjusted with caster 4* positive caster, 1/2* neg. camber, toe-in 1/18. I found a front end shop that does not have the fancy computer allinment but the older method. So he could not give me a print out of the exact set he obtained but guaranteed it was the dim. I asked for He said he had no way of checking the rear. I am using both upper and lower adjustable rear arms At 70 mph I can release the steering wheel and it does not pull or wonder. Car sits about 3 in. lower than stock in front and about 2 in lower in rear, depending on psi. in air bags.
JIM82,
You are correct there is not much of a quick response feel on center with the variable box, when turning off center.

Sounds like about where I would like to take my '68 Elky... where did you come up with 500 lb/in springs for the front? Custom wound?

What spring/rate do you have in back?

Custom wound by Coil Spring Specialties 632 W. Bertrand St. Mary's Ks. 66536 Ph. 785-437-2025. This is a small block with iron heads, copper radiator 3 core. Using 1 1/8 front sway bar.