Status
Not open for further replies.

Macguyver

SOUTHSIDE MACHINE PERFORMANCE
GBodyForum Sponsor
Mar 21, 2017
285
63
Why Modified Front End Geometry is Needed

If you want to improve the handling of your ride, you must first understand what is wrong with the original geometry. From the factory, these cars were designed to understeer. To make them do this, they used a very short spindle with the upper A-arm at a steep downward angle, which results in a backward camber curve making the tires lean out of a turn, using only the edges of the tire. Not only is this bad for mechanical grip, it's also why every stock Chevelle, S-10 or G Body wears the outside edges of the front tires. Below is a diagram of the stock geometry at rest, and then in a hard turn. Notice the severe angle of the tires. All of the cornering forces are placed on a very small area of the tire.



To deal with this problem, there are several things that will help. Simply lowering the car will help to some extent, but not nearly enough to correct the whole problem. Bigger sway-bars will reduce the amount of bad camber gain, but again, it's not enough... it's like a band-aid on a gunshot wound.
To fix the bad geometry, you need a taller effective spindle height. The "effective height" of a spindle is from the pivot center of the upper balljoint to the pivot center of the lower balljoint. Tall spindles with stock balljoints, or stock spindles with extended balljoint studs will both achieve this goal.
Below is a diagram of the same car equipped with a taller effective spindle height. Notice that the tires remain near vertical using the entire tread evenly across its contact patch. This is key to getting the most grip, and life out of your tires.

FRONT END HANDLING KITS EXPLAINED.

Improve handling and fulfill your rides built-in performance potential by installing our tubular upper a-arms. The relocated ball joint plate on these a-arms permits greater positive caster. Expect improved steering feedback courtesy of increased caster and a precise feel due to the deleted bushings and replaced with roller bearings. Features include grease-able steel cross shafts and improved header clearance. These track-tested, jig built DOM a-arms are supplied with a durable gloss black powder coat finish which guarantees your performance parts stay beautiful on your street car, drag car, autocrosser or Pro-touring machine.

The SSM Stage 1

The secret is the combination of the extra tall ball joint to match your new tubular upper arms which greatly improves the camber curves and relocates the roll center. This means more grip and less body lean. The 1" EXTRA tall upper ball joints reverse the backward factory camber curves for a huge increase in grip. They also raise the extremely low factory roll center to dramatically reduce body roll

For stock and lifted cars this radically corrects poor ball joint angle and helps the arm clear the frame when lifted properly.

For drag racers SSM Stage 1 Plus allows faster weight transfer and more positive caster for better top end stability.



The SSM Stage 2

The stage 2 goes even a step beyond the Stage 1 Plus and further corrects the terrible backward geometry of the factory front suspension, by using Racing Series ball joints, the ONLY ball joints made 100% from US materials in the USA!

They are much stronger, smoother, and longer lasting, than original GM, or any other aftermarket ball joint. The .5" taller lower ball joints further improve the camber curves and roll center location, significantly reducing lateral roll center migration for more predictable behavior.

They also correct the factory bump steer issues by raising the tie rod ends into proper alignment.Now with extremely improved geometry designed for the rigors of SCCA, TransAm and NASCAR your car will truly dominate the street and track!

Additionally, all low-friction ball joints have 32 degrees of swing angle for maximum suspension travel and contain no springs or plastic parts. Dust boots are not included but available.



Changing just the upper A arms can only do so much. The length and offset of the arms has very little effect on camber change, roll center or overall handling. They add + caster which can make the car track straighter at speed and improve turn in. However too much can make the car feel vague and the steering sluggish so that only goes so far. As the + caster is increased there is a tiny improvement in camber as a side effect when the wheels are turned. Our upper arms have this benefit as well as more caster adjustment. To make any profound improvement in the suspension geometry of cars that need it the actual pivoting points (pickup points) that determine that geometry need to be moved vertically. Road race cars like SCCA, TransAm, LaMans Series race cars and fast DRAG CARS use special taller spindles, raising the upper ball joint pivot points like our Stage 1 and 2 packages do. This was the genesis of our AFX tall spindles for the GM A Body platform cars. For years circle track racers that run stock G or F body chassis have used taller truck upper ball joints, which seated improperly to improve the geometry. They’ve been doing this kind of thing for years by fabricating new parts, mixing and matching stock parts, modifying suspension/frame mounts etc. That’s how to win races with a less than perfect factory chassis and a small budget. We’ve taken that race experience, applies new technology and brought it up to date with our SSM STAGE 2 package. Major suspension improvements, not just shiny parts.

Much of it also has to do with alignment. A lot of folks think if their car goes straight and doesn't chew up the tires that it's aligned properly and working as well as it can. They're kidding themselves and they're missing out on a LOT of performance. The alignment specs recommended in the `60s and `70s (and even `80s!) were anything but performance oriented. In fact they've changed little since the 1940s. Today almost every car is using power steering and we're all running high performance radial tires (except for the resto guys but that's another story...) these tires are often more than twice the width of the originals, we've also got another 40 years or so of experience to draw on. What's more, once we've corrected the geometry so that it works like a new performance car it demands the same type of alignment those cars run to achieve peak performance.

Modern performance cars run a LOT more + caster and - camber. The + caster helps the cars track better at highway speeds and gives better steering feel. The - camber helps keep the tire's contact patch flat on the road surface during cornering. It's part of what makes new cars drive like new cars. Using these kinds of settings on older cars yields a BIG improvement in drivability and performance but because they were designed around different specs it's usually impossible to attain the best numbers with stock parts and shims. Lowering the car or increasing the effective spindle height with taller spindles or taller ball joints all add more + camber making it ever harder to dial in a - camber setting (which is what we want). That's the big reason for different upper arms. The taller spindles or tall ball joints make the big geometry improvements and the proper upper A arms make it possible to combine the new parts and geometry with the proper performance alignment, an unbeatable combination!
 

Attachments

  • SSM CORRECTION - Copy.gif
    SSM CORRECTION - Copy.gif
    227.1 KB · Views: 656
  • 1.png
    1.png
    133.6 KB · Views: 632
  • 2.jpg
    2.jpg
    38.9 KB · Views: 486
  • 3.jpg
    3.jpg
    37.9 KB · Views: 453
  • rs=w_600,h_600 (2).jpg
    rs=w_600,h_600 (2).jpg
    42.5 KB · Views: 516
  • rs=w_600,h_600 (4).jpg
    rs=w_600,h_600 (4).jpg
    32.6 KB · Views: 505
  • Like
  • Informative
Reactions: 5 users

MechMan

Master Mechanic
Sep 13, 2018
294
28
Long Island NY
I am interesteed in your ultimate handling kit. Is this just for the front end? Would the control arms work well with the QA1 coilovers?
 

vanrah

G-Body Guru
Apr 16, 2013
852
93
Near Afton, Wisconsin
Greetings [B]Macguyver[/B] & all; Thank you for an excellent write up. This is what I've been trying to say for years but is hard to put into a few senescences. I started the project (Geometry change) back in 2003 with just uppers then as hobby money became available I was able to finish with lowers back in 2011. Total different car would be understatement. And from reading your fine write up I've learned a bit more (retaining the new info will be the challenge) that could add a bit more of improvement.
I would suggest to our fine moderators that this should be saved & made easy to access. Thanks again, Ole' Bob.
 

Attachments

  • IMG_6269 (2).jpg
    IMG_6269 (2).jpg
    556 KB · Views: 221
  • Like
Reactions: 3 users

Silent viewer

Royal Smart Person
May 9, 2007
1,459
63
Is there any issues not having bump stops on these arms? I am worried that an arm like that would come in contact with my frame. Thanks
 

melloelky

Comic Book Super Hero
Oct 22, 2017
3,155
113
mass
they will contact the frame when the suspension is @ full droop,say when you have stands or lift arms on the frame.
 
  • Like
Reactions: 1 user

Silent viewer

Royal Smart Person
May 9, 2007
1,459
63
I think that is the single biggest thing pushing me away from this kit. Not just for when lifted but when driving.
 

melloelky

Comic Book Super Hero
Oct 22, 2017
3,155
113
mass
I think that is the single biggest thing pushing me away from this kit. Not just for when lifted but when driving.
i agree,i was in your shoes a few years ago and ended up polling three company's. like you i was turned off by the sc&c because not only did i body work my frame and didn't want the non bumpstop thing but after following another members build about the fits he had that was adjusting those turnbuckle style arms that are straight out rather than down towards the spindle itself.
 
Last edited:

69hurstolds

Geezer
Supporting Member
Jan 2, 2006
5,639
113
One of the things you have to remember is these types of kits, et al, are designed for the people that run off-road. This isn't for your daily driver or street cruiser. Another example of sh*t you likely don't actually need on the street. Not all of it, but some of it doesn't add up to a hill of beans stoplight to stoplight. If you're going to carve corners on the track, then you can use all of this stuff to take advantage of the increased handling abilities of the car to the max. Another example of parts designed for one type of application and potentially used in another. Will they work? Yes. Is it the smartest idea for street use? Overall- No. Sure, taller ball joints, or special spindles, or anti-bump steer stuff, that's all good for street stuff too. But know what your goal is and build the car accordingly.
 
  • Like
Reactions: 2 users

69hurstolds

Geezer
Supporting Member
Jan 2, 2006
5,639
113
You are gonna have a real hard time trying to convince me that a stamped steel arm is as good as a tubular arm. Ibhave personally driven a car that had all of the work that I am currently doing to mine done to it. It handled night and day difference compared to a stock g body. I am pushing 40 and have owned a g nodybof some sort since I was 13 or 14 before I could even drive. I have had them dead stock, had them on many different sizes of wheels, full air ride setups, had buddies with hydraulics on them. You name it, I have riden in it. My buddies monte ss that had everything i am doing to his car drove beyond what i ever imagined a g body could do. Everyone seems to be trying to tell me not to do this stuff. Sure start with a stock car, been there, done that. This one is starting from a bare frame literally. Built ground up regardless of what everyone else is telling me to do. I have driven what I want and I'll be famned if some internet experts tell me I'm waisting my money. This site use to have encouraging people, more folks anymore with opinions. And sorry, that isn't directed at you per say, several folks today trying to bash what I'm doing. I left this site twice already and told myself I was done with the internet bullies but I keep coming back. Sorry a beer or 3 has me ranting now. Sorry
I think you're misunderstanding. I never tried to convince anyone that a stamped arm is as good as a tubular arm. Nothing I said was directed at anyone in particular. I wouldn't tell you what or what not to do to your car. The original post makes great sense out of things to consider when looking at parts to make your car handle.

I was simply rhetorically speaking trying to help people understand that there's a time to apply these parts and a time that you should rethink purchasing expensive parts that might not get you where you want to go if you don't use them as intended. As with engine performance parts, suspension components need to compliment each other. You probably aren't surprised, like I am, at the strong lure of throwing money at a project only to be disappointed because you didn't get the combination right. Just because it's a race part doesn't mean it's automatically transferable to street use.

I'm not going to be a cheerleader for spending other people's money for no good reason. Your personal build has a purpose, so if it's a carving machine you want, I'm with you on the fact you aren't going to get there with a G-body on a flimsy frame and stamped steel arms. I get that. But because YOU'RE doing it with maximum handling in mind, you were never the target of my opinion. In fact, you reinforce it. There's a whole lot of wannabes out there who buy all this stuff to put on their car that will never push it to the limit and for what? Because it's pretty colors and looks cool? Ok. Nothing wrong with looking cool while you're doing something, but if you're throwing hard-earned $$ at your car, I'm of the strong opinion that you should make it count for something.

This goes right back to my opinion of only putting money into hard parts on a project where and when it makes sense. Tubular A-arms will not help you all that much in the handling department if that's all you do to a street car. Sure, there are advantages of having them, but everything has to work as a team with suspension components. Only as good as your weakest link.
 

Max Headroom

Master Mechanic
Sep 8, 2011
369
63
There is a lot of sense in what 69hurstolds is saying. It's not about whether or not you (as in anybody) buy some of the suspension parts for your project. It's that if you don't buy the parts that work in harmony to achieve what your handling goals are, you are not going to reach those goals and you might as well not spend any of the money. I think he is saying, "Know what you want the end result to be and then buy what it takes to get that result." I don't think he is bashing what you or anyone is doing to their ride. It's your ride and should be exactly what you want it to be.
 
Status
Not open for further replies.
G-Body Performance Upgrades

GBodyForum is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to amazon.com. Amazon, the Amazon logo, AmazonSupply, and the AmazonSupply logo are trademarks of Amazon.com, Inc. or its affiliates.

Please support GBodyForum Sponsors

Classic Truck ConsolesDixie Restoration DepotMike's MontesP-S-TSouthside Machine PerformanceUMI Performance

ContactAdmin@GBodyForum.comfor info on becoming a sponsor