Just curious:

I have heard from Global West (and now a "tech" response in the latest Car Craft) about problems with stiff rear springs and rear sway bars on cars equipped with "Taller" front spindles (B-body, but I am assuming this would apply to Tall Ball Joints...)..

Just curious on the "Gurus" take on this...

I currently have a "Chromed" factory sway bar mounted on my GW lower rear control arms (TBC-4? with sperical and Delrin?)... Now I am getting ready to get tall ball joints (SC&C), and worried if I really should get rid of the rear bar, or if it won't be a big issue (no track time in this car...)...


Also curious what anyone here thought about Jeff Smith mentioning B-Body tall spindle swap as being the "Best" alternative for improving the camber on an A-body? Advertising pitch for Global West?

It’s not one of the same "gurus" at GW that recommends the tall spindles they sell is it? I would have a real difficult time believing anyone at GW has a single clue as to what it takes to make an "A" body turn a corner.

Since I haven't read the article yet i give him the benefit of the doubt and hear his argument (I'd really like to hear his argument for running "B" spindles as a favorable upgrade) for this. What did he state the big problems would be by increasing rear roll stiffness and using a tall spindle? I assume he had nothing negative to say about the front but rather blamed the rear since they sell the "B" spindle as part of their "high-end Cat V1" or whatever package.

The biggest problem is that the "B" spindles ruin the front geometry so bad that it is very easy for the rear to come around when the front wash’s out. So in essence there is some truth to it. “The front really sucks so we need to keep the rear real soft to prevent over steer”. That is like we need to de-tune the engine because it makes too much power and is breaking the tires loose….don’t fix the traction issue, just dump some power.:sad:

I have not read the article either... but one line of thought might go like this:

In stock form most all vehicles are designed/tuned to understeer. This is the safest approach for the general John/Jane Q Public driver.

On top of this we add the tall spindles (or tall ball joints) to change the camber curve and possibly (likely) the caster angles. Now the tire stays closer to vertical and gets much better traction. So it has a higher limit and we have less understeer.

Now we stiffen the rear which causes more weight transfer in the rear. This is how we tune/increase oversteer.

If we increase oversteer and decrease understeer at some point we go from overall understeer right through neutral into overall oversteer.

Although when you put the "snap" word in there it starts to sound like they are merely thinking/talking about the crummy C4L rear suspension design in the Chevelle.

Let me rephrase the question/info...

by "gurus", I meant the guys here with actual knowledge, like Dennis, etc...

For my car, Mostly street cruiser, but planning on the tall BJs. Have Hotchkis springs up front and a 1-1/4" swaybar... Should I keep the year bar? Will it make a difference either way??? What should i get for rear springs (I want to bring it down an inch or 2, and my rears are "New" stock replacements)??? I just want to minimize my risk...

In Car Craft (in the "What's your problem" tech section), July 2006 issue with the 68 Chevelle on the front, Jeff Smith says,"
The biggest hurdle to good handling... is the front camber curve... The best way to fix this is with a 1-inch-taller '77-'96 B-body spindle and a custom tubular upper control arm from either hotchkis or Global West... The tubular upper arm from Global, for example, alters the camber curve to roll negative camber, which is exactly what you want to improve handling. If you do this, you'll need to run the lightest rear coil springs you can find. Otherwise, the car will instantly oversteer in the corners very easily...

Way back when I bought my lower rear arms from GW, I inquired about how to mount he swaybar... I believe it was Doug I was talking too, and he said I don't want or need to run one (I WAS planning the tall spindle swap at the time).

I have heard it from a few other people, but not sure if they just heard this same info from GW, etc...


Jeff Smith DID achieve over 1g on the skidpad with this setup on his '65 Chevelle, and I still think its a great improvement over stock. but obviously not the BEST way to do this...

In his support, it probably WAS the best method for many, many years, and it seems as if we are just now getting bolt-on systems of better design...



Of course, in the same issue, there was the article on the 68 Chevelle( by Douglas Glad). The the "Tech Notes" there was a remark about the "Big meats"...
The 295/50-15 meats were the first thing we noticed, having owned and operated several Chevelles and El caminos with 255 and 275 tires that rubbed and smashed into suspension parts...

Wow, YOU'RE the editor, and you don't know how to properly check the backspacing on your wheels??? While not exactly "common", I have seen countless Chevelles over the past 10+years with 295s tucked in the back, without major mods, and even NO mods at all...

Makes me wonder why I still get this magazine... Its going downhill fast...

OK Tony, the guy who is writing tech for Car Craft needs a slap of reality right in the mouth. He is obviously not up to speed on the geometry woes of the "A" body. Keep in mind the guys who do the Q&A for most of the magazines are NOT industry experts, they just some guy at the magazine elected to answer questions.

Obviously the "B" spindle (we will refer to it only as the "B" spindle from here on out as I have finished my own "tall" spindle swap which works the way it is supposed to) is not the best or even one of the alternatives I would suggest for improving the handling of the "A" body. The editor doesn't even fully understand how the spindle/shorter arm works as he refers to the fact that the tubular arm will change the camber gain witch is not even remotely factual. The spindle changes the curve via its moving the location of the upper ball joint which is one of the 4 points that form the trapezoid used to measure FVSA length and determine items such as front roll center height, lateral RC migration, CAMBER GAIN during roll/bump, and even scrub to a degree.

In your application I would leave everything as you had already planned, for lowered rear springs, I like the SS replacements from the circle track supply houses. Stick with a 150# to compliment the 550# Hotchkis springs you are running on the front (I believe they are 550#). The rear bar is a tuning tool and you can only determine whether or not to use one based on driver input. Some cars and or drivers will want it; some won't depending on all of the specifics unique to each application. Every car is different and there is no blanket statement we can use like “no car should have rear bar if you have “B” spindle” (foolish editor mistake #3).

BTW, I'm sure it wasn't intentional but Steve is a really bright guy. Engineer, right Steve?

Sorry not trying to make anyone feel dumb, just doing my typical answer explaining how to fish rather than providing the fish. It can be frustrating if you are just looking for canned fish/answers though.

I got the impression initially you were trying to understand what the magazine writers were thinking, so I tried to provide a line of reasoning...

Now if you really want to match up some rear springs... you need to know what the sprung weights are front/frear, the front wheel rate (can be figured out from front spring rate but *not* from "Hotchkis"), a natural frequency graph, and the desired rear fitted spring height. Then you just need to find the product that best matches the spring rate and length parameters you come up with. And when you are all done, tune the front and rear lateral weight transfer characteristics to your tastes with anti-roll bar selections.

Or you can just take and trust whatever Dennis says :thumbsup:

Yeah I do make a living as an engineer which, combined with my budget, makes me take more of an analytical perspective rather than a expiremental approach. Not to mention that I find learning/figuring how it works quite entertaining. Don't get me started on my current topic: EFI fuel systems.

Since I run GW stuff (right now anyways) and have spent a lot of time on the phone with them and a lot of seat time with them I'll chime in.

I had most of my snap oversteer issues running Hotchkis boxed arms with all poly bushings-- the rear roll stiffness was so high and the suspension action so unpredictable because of the bind that the rear had a very nasty tendency to "skip" over bumps during cornering and step out of line. It was OK on perfectly smooth corners but toss a little bump in the corner and out came the rear end in a BIG hurry. To make things worse, because the roll stiffness was so high and unpredictable because of the binding it was difficult to get it back under control. The snap oversteer issue in my experience has much more to do with bound up rear suspension action because of the non-linearities induced by not only the poor geometry but also the boxed arms and poly bushings binding up movement. Best thing to do is reduce as much bind as possible. Oh, and make sure you aren't contacting your bump stops in hard turns because of a drastically lowered ride height because you'll also get snap oversteer. Wheee! Fun lesson the first time it happens.

However, even with the binding reduced too much rear spring rate or roll stiffness (via a too-big sway bar) can also cause nasty excessive oversteer tendencies-- so you will have to tune with rear spring rate / sway bar. Tire size front to rear will also play a big role in this area.

My preference is to take care of the bind issues as best you can and then work with spring rates from there to tailor the handling to your liking-- because the rear sway bar mounting on our cars from the factory is definately not ideal and not a very effective mounting solution. Should you need a rear bar you would be FAR better off retrofitting a 3rd-Gen F-body setup where the sway bar is attached to the axle tubes via large clamps and then the end links are connected up to the frame. This is a much more effective setup than the factory method and actually would not be very hard to adapt to our cars.

As far as the rear bar, as Dennis said that is very dependant on the entire combination. Right now my car in max-effort turns has just a bit of rear rotation and will very controllably slide the rear around the entire turn based on throttle input. With a vehicle with a huge wheelbase such as our cars this is about the fastest way to get it to go around a turn. I will admit that it's a bit "on edge" for the street because of the rear slip angle but that could be tamed by going a bit softer on the springs out back to put a bit more understeer back in it. It will not snap oversteer or get WAY out of hand-- in fact if you botch a corner entry it will typically push; but if you get the corner entry right and then use the throttle to get the back slipping a bit the rear is very predictable throughout the entire turn.

For reference, my current setup is:

Front:
GW LCA/UCA with del-a-lums
B-body spindles
750# springs
1.125" front sta-bar
Alignment: 4.5 degrees caster / -0.375 of camber / 3/32" total toe in

Rear:
GW TBC-4 lowers (spherical bearing)
Edelbrock uppers with rubbers in the rear end
No sway bar
175# springs

I will probably be going to either 850# or 1000# springs up front when I re-do the front suspension and I'll re-evaluate the rear spring rate at that time. I'm also going to wider wheels and tires in the next few weeks which will undoubtedly change the handling; if anything it should reduce the rear oversteer condition and require slightly heavier rear springs to bring it back to where I like it.

Thanks guys,

Troy, make sense about the binding of the C4L being the likely culprit of the "snap" gossip... I too had the "skipping" of the rearend with all-Poly in the rear, and switched back to new rubber bushings in the stock upper arms ( and the TBC-4 lowers)... Plan to go Edelbrock/Currie uppers in a few months (maybe with Wolfe racecraft spherical bushings)...

Dennis, I realize often the tech guys don't have much clue, but when the answer came from Jeff Smith (I liked the articles where they got his 65 Chevelle to pull 1g years ago), I was a little confused...

I too am an engineer (okay, so my degree is in Civil, but still have some background and that analytical way of thinking about stuff), and when I read anything (even here), I take it with a grain of salt... And even IF I agree it makes sense, I still try to apply it to my situation, and then look at my budget to figure where I want to be...


Since its a "street" car (maybe someday I'll try to AutoX it), and I don't drive as crazy as I used to, my main concern is keeping it under control in normal driving situations (hence the worry about the snap oversteer). While not "ideal", stock geometry probably wouldn't kill me, but nice to take it to the next level... Probably never as in depth as Troy and Dennis (at least in this car)...

Thanks,

Tony

Dennis, I realize often the tech guys don't have much clue, but when the answer came from Jeff Smith (I liked the articles where they got his 65 Chevelle to pull 1g years ago), I was a little confused...
Tony
It's easy to hit 1g with the right tires. "G" measurements are very deceiving also as they are measured in a stable wide circle where no dynamic changes are being made. I have seen cars that pull 1g on a skid pad but handled awful attempting to negotiate a mild road course.