Best front end changes for high speed stability?

Wageslave

Wageslave

Royal Smart Person
Jan 25, 2017
1,042
113
Now that I have the drivetrain on the Bonneville in a pretty good place, I was thinking about going to the track this spring to see what it can do. My main problem is that my estimated trap speed is about 105 mph and these cars get floaty above 90-95.

What is the best way to get the steering a little more stable? I would prefer to not lower the front end much if possible, since the roads around here look like they have been through a war, but am open to the option.


Thanks
 
B

bracketchev1221

G-Body Guru
Jan 18, 2018
578
93
Pretty much what has been said. good front end parts to make everything tight, a good alignment will help greatly. Otherwise, a good idea is a front end alignment at ride height. When I had the race car we would raise the front end up an inch or 2" and perform the alignment at that height to simulate going down the track. My car went dead straight over 150 mph with stock front end parts. Another helper if you are really serious is front end travel limiters to keep the front end from changing angles.
 
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motorheadmike

motorheadmike

Comic Book Super Hero
Nov 18, 2009
4,844
113
Ottawa, Ontario Canada
Tires.

I had my wagon up to 116mph last Summer and it was very uneventful.
 
Macguyver

Macguyver

SOUTHSIDE MACHINE PERFORMANCE
GBodyForum Sponsor
Mar 21, 2017
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Fix the geometry! Toe, and Caster play a huge role.
We have several write ups on here discussing this.

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.

THE SSM STAGE 4
SSM ULTIMATE FRONT END KIT "THE GAME CHANGER!" G-BODY



SPINDLES


Tall Pro Touring Forged Performance Spindles for the G-Body. Raises Roll center, lowers center of gravity (0"-3" drop), virtually eliminates bump steer and creates a negative camber curve that surpasses the C7 Corvette. Uses larger bearings with a wider separation and will accept OE GM 11-14 inch rotors. Huge single piston to 8 piston caliper options as well. Bolt on fast ratio steering arms. Even the ball joint tapers are larger.

Designed around stock and aftermarket lower control arms.

Powder Coated Black


ADJUSTABLE A-ARMS

GM G-Body adjustable upper A-Arms come with QA1 XD Series Chromoly PTFE Lined Heim Joints and 4130 chromoly adjuster sleeves, optional 6061 -T6 aluminum.

These Adjustable upper control arms adjust on car and allow extreme camber and caster change for the ultimate performance. These adjustable arms also allow the use stock of the huge OE Mopar Muscle car ball joints and no need for alignment shims and you also gain header clearance. Powder Coated Black



Kit includes 2 of the following...



  • SSM Tall Forged Spindles
  • SSM Adjustable Upper A Arms
  • SSM Fast Ratio Steering Arms
  • QA1 or Moog Upper Ball Joints
  • SSM QA1 Hybrid Lower Ball Joints
  • Moog Oversized Premium Tie Rod Ends
  • Moog 575# Touring Springs
  • Call about Coilover Options





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!

The low-friction ball joints are legal for classes that require non take apart joints or OE style joints. Additionally, all low-friction ball joints have 32 degrees of swing angle for maximum suspension travel.



FRONT LOWER CONTROL ARM BUSHING KITS

The newest G Body out there is 30 years old, most are older. Time to face the fact that your stock rubber bushings are shot. Stock rubber bushings wear out in as little as 5 years. Road oils and heat are their death, they get hard then crack.

Not just on the lower control arms but on the whole car. They wear out due to age not miles. You already know this if you are replacing suspension parts such as front or rear control arms. If your car's handling seems a bit on the sloppy side lately, then replace your mushy rubber bushings with our solid or polyurethane control arm bushing sets. These polyurethane bushings are unaffected by oil, smog, road salt, and most chemicals, so they won't soften, compress, or distort like rubber does. The steel 2 piece have grease zerks and are designed for competition cars. So, next time you turn the steering wheel, take a high-speed corner, or accidentally hit some potholes, our housing bushings will give your ride the buffer and control to handle the roads ahead. Both sets come with new grade 8 hardware.



SSM CORRECTION - Copy - Copy (3).jpg
 

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Supercharged111

Master Mechanic
Oct 25, 2019
423
93
You could also try to reduce lift at speed by venting the hood, adding an airdam, and lowering the car. Yes the stock geometry and alignment specs blow, but that doesn't mean much in a straight line.
 
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Clone TIE Pilot

Clone TIE Pilot

Royal Smart Person
Aug 14, 2011
2,179
113
Galaxy far far away
A rear frame brace will improve steering. I made my own brace out of square tubing stock from Lowes.
 
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ssn696

ssn696

Older Than My 1980 Malibus
Supporting Member
Jul 19, 2009
4,099
113
New Mexico
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pontiacgp

pontiacgp

Canadian Prime Minister
Mar 31, 2006
27,206
113
Kitchener, Ontario
if you want a G body to handle you need to start with a boxed frame, frame braces ,new body mount bushings, new control arm bushing. You also need to lower the car and use tall ball joints is required to get your front upper control arm ball joint above the cewnter point of the arc so the camber increases as you compress the suspension. With the stock set up the control arm is pointing down so as youn compress the suspension the top of the tire goes out give you positive camber before it starts to give you the negative chamber that you need in a corner
 

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