1971 C/S. All original other than 1" rear sway bar and new boxed lower trailing arms. Bilstein shocks all way around. Ride quality/handling, in my opinion, has noticeably improved. Inspected front suspension and components and found no slop/play. Power steering works exceedingly well. One finger. It seems a liitle fast for my liking and as I'm driving I find myself minutely correcting it often. Feel the straight line tracking wanders. New tires and alignment. Seems like most want faster steering (quicker ratio gear boxes) Will recheck how many turns stop to stop is, but last I remember it was 3.25. So I.m guessing 14 to 1?

To help with better straight line tracking: Try more positive caster? If so, how much? Would the steering arms from Global West help enough to warrant the expense and labor? https://www.globalwest.net/a-body-19...bumpsteer.html. Looking for straight line stability. It is a cruiser, never raced. Always driven at or slightly less than posted speed limit. George

 

George, I had the same problem as you described with slight wandering on my 1970 Vista Cruiser. I felt I needed to make frequent small steering corrections.

I put in the Global West upper control arms and longer upper ball joints. I told the alignment technician to dial in as much positive caster that he could reasonable attain. That was about +2 1/2 °

I also installed a set of gears in my steering box that would give me in the range of 12:1 ratio.

The result was transformative for tracking on the highway. It tracks as well as a modern car.

You ask if "more positive caster" would help. With my original parts, I couldn't reach positive territory. If you have your alignment checked, you will probably find the same. Make your goal "positive caster."

I had a similar experience to yours when adding a 442 rear stabilizer bar. At 7/8" diameter, it eliminated most cornering sway and the car responded better to steering changes.

And I learned something about vehicle dynamics. With a car having 53% of the weight on the rear tires, a 442-size stabilizer bar with a 15/16" front bar results in OVERSTEER. It sure was fun, but I was concerned about other people who would drive the car. So I increased the front stabilizer to 1 3/8." That sharpened the steering response even more and changed the handling to almost neutral. Increase in ride harshness was not easily felt.

Gary

 

As Gary notes, while positive caster will benefit handling and tracking, it can be difficult to achieve this with the stock suspension components. This caster change is one of the primary reasons for the difference in steering feel from older cars to newer ones. Back when manual steering was standard equipment, caster angles were chosen to minimize steering effort. With power steering this is no longer necessary. The 73-77 A-body cars, which were praised for their improved handling and steering feel over the 72-earlier cars, used 4-7 deg of caster angle.

 

Thanks for your reply. Your experieces fell right in line with what I was thinking. Will look at a 1.25" front stabilizer bar. See that recommendation repeatedly on here. Hoped someone had experience with the steering arms from Global West. Never thought about the Vista Wagon having a rear weight bias. Hate to get too carried away with changing away from original. Glad to benefit from your gains and experiences. Thanks again.

 

The 64-72 A-body cars are understeering pigs from the factory, especially with a heavy big block over the front end. Herb Adams would use a larger rear bar than the front bar to get neutral handling - 1.375 front and 1.5 rear. I've managed to stumble across a couple of the 1.5" rear bars. The 2nd gen WS6 TransAm 1.25" front bar can be used on the A-body cars with the F-body end links. I've bought a bunch of these at swap meets in the $25-$50 range.

 

Joe, read the article you posted about the later models improved suspensions. A lot of Gm models, seemed to me, improved from 74 up. Reading your posting is where I came up with the positive caster maybe working. Not smart/educated enough to have figued that out on my own. Sharing information really helps us inexperienced mechanically. Have seen suggestions on longer spindles from 98's. Taller ball joints. Tubular "A" arms. Offset upper "A"arm crossshafts. Saw the global west steering arms for bump steer and wonder if they would help? Plus they are easy to install. Thanks.

 

The biggest problem with the suspension on the 64-72 A-body cars is the camber curve that changes with suspension travel. The stock suspension moves the tire in the opposite direction from what is desired for handling. This is why the aftermarket offers tall spindles/tall ball joints to correct that problem. H.O. Racing first publicized the B-body spindle swap back in the 1980s to correct this problem. Unfortunately the integral steering arms on those spindles introduces bump steer that somewhat negates the handling improvement from the tall spindles. In addition, the tall spindles require a lot of shim to get the correct alignment, which causes a problem with big blocks or headers. The Global West short upper control arms were designed to fix this problem. Today you can get tall stock-type spindles with bolt-on steering arms or tall ball joints that use the original spindles.

Bump steer is a different problem. If you are serious about this, the best thing to do is to get a bump steer gauge to both figure out where the car is today and to dial in the steering arm corrections.

https://www.motortrend.com/how-to/measure-bump-steer/

 

Thanks for the almost instant replies. I will study the supplied technical data thoroughly and determine my level of seriousness. If this was my daily driver I'd be all over the recommendations. I probably will put around 2500 miles a year. I certainly have gained knowledge wise about suspension terms and geometry. As I maintain my suspension and parts need replacement. I will use the recommendations to improve the car. I now have member proven options. Wow, what a community.