S197 Mustang GT Suspension Overhaul

The Problem

This 2008 Mustang GT came in with classic S197 complaints:

• Vague steering feel
• Excessive body roll in corners
• Rear end “walking” over bumps
• 85,000 miles on original suspension components

The owner wanted a proper handling car for spirited canyon driving, not a drag strip queen.

Inspection Results

We put the car on the lift and found what we expected:

Front Suspension

• Control arm bushings cracked and deteriorated
• Ball joints had play (not dangerous yet, but not great)
• Struts blown - no resistance on compression

Rear Suspension

• Lower control arm bushings completely shot
• Panhard bar bushing worn out (causing the “walking” sensation)
• Shocks similarly blown

Chassis

• Factory spot welds holding, but chassis flex noticeable
• No subframe connectors from factory (convertible has them, coupe doesn’t)

The Build Plan

Rather than just replace worn parts with OEM equivalents, we spec’d upgrades that address the S197’s known weaknesses:

Front End

• BMR tubular control arms: Stronger than stock, adjustable caster
• Koni STR.T coilovers: Height adjustable, valved for street performance
• Steeda bumpsteer kit: Corrects geometry when lowered

Rear End

• BMR adjustable lower control arms: Allows pinion angle adjustment
• BMR adjustable panhard bar: Properly centers rear axle
• Koni STR.T rear shocks: Matched to front

Chassis Reinforcement

• Maximum Motorsports subframe connectors: Ties front and rear subframes together
• Welded in, not bolt-on (much stiffer)

Installation Highlights

Subframe Connectors

This is where the real improvement comes from. The S197 coupe chassis flexes significantly under load. The MM subframe connectors:

1. Required welding along the entire length (8 feet total)
2. Car was on rotisserie for access
3. Seam-sealed and undercoated after welding
4. Immediately noticeable difference in chassis rigidity

Coilover Installation

The Koni STR.T coilovers went in smoothly:

• Set initial height to 1.25” drop (front and rear)
• Left damping at factory recommended settings
• Torqued all fasteners to spec with car on ground

Rear Suspension

The adjustable control arms and panhard bar allowed us to:

• Set pinion angle to 2 degrees down (optimal for street)
• Center the rear axle perfectly in the wheel wells
• Preload the bushings at ride height

Alignment

With the new components installed, we did a full corner balance and alignment:

Spec	Front	Rear
Camber	-1.2°	-1.0°
Caster	+5.5°	N/A
Toe	0”	1/16” in

This setup provides excellent turn-in response while maintaining good tire wear for daily driving.

Results

Before and After

The transformation is dramatic:

Steering: Direct and communicative. The vague-on-center feeling is gone.

Body Roll: Reduced significantly without harshness. The car stays flat through corners.

Rear Stability: No more wandering. The rear tracks true over bumps and transitions.

Ride Quality: Firm but not harsh. The Koni valving is perfect for street use.

Owner Feedback

After 2,000 miles, the owner reports:

“It’s a completely different car. I actually look forward to curvy roads now instead of dreading the body roll. Best money I’ve spent on this car.”

Cost Breakdown

Category	Cost
BMR Components	$1,200
Koni Coilovers/Shocks	$950
MM Subframe Connectors	$250
Steeda Alignment Parts	$180
Labor (20 hours)	$1,800
Alignment	$150
Total	$4,530

For under $5,000, this car handles better than many cars costing twice as much. That’s the value of addressing the fundamentals rather than chasing horsepower.