The Factory Five Racing GTM is a mid-engine supercar replica that demands a well-sorted suspension to match its potential. Whether you are building a GTM from a kit or upgrading an existing car, choosing the right suspension parts is critical for handling, ride quality, and safety. This guide covers the essential FFR GTM suspension parts, what to look for, and how to make informed decisions for your build.
Stock vs. Aftermarket Suspension
The factory-supplied suspension on the GTM is functional but leaves room for improvement. Stock components include basic coilover shocks, control arms, and sway bars. While they provide a baseline, many builders find that aftermarket parts offer better adjustability, durability, and performance. Aftermarket options allow you to fine-tune spring rates, damping, and geometry to match your driving style—whether that's street cruising, track days, or autocross.
Key FFR GTM Suspension Components
Coilovers
Coilovers are the heart of the GTM suspension. They combine a shock absorber and spring into one unit, controlling both ride comfort and handling. For the GTM, popular choices include QA1, Aldan American, and Koni. When selecting coilovers, pay attention to spring rates: a typical street setup might use 400-500 lb/in front and 500-600 lb/in rear, while a track-focused build may go higher. Adjustable damping is a must for dialing in the ride.
Control Arms
Control arms connect the chassis to the uprights and define the suspension geometry. FFR GTM uses upper and lower control arms in the front and a multi-link setup in the rear. Aftermarket control arms are often made from tubular steel or aluminum for weight savings and strength. Look for options with adjustable ball joints or rod ends to adjust camber and caster. Stock arms work, but upgraded arms improve alignment range and reduce flex.
Sway Bars
Sway bars (anti-roll bars) reduce body roll during cornering. The GTM benefits from thicker or adjustable sway bars, especially for track use. Aftermarket bars allow you to fine-tune roll stiffness independently. Pair them with upgraded end links for reliability. Common brands include Hotchkis and Speedway Motors.
Spindles and Uprights
Stock GTM spindles are robust, but aftermarket options can reduce unsprung weight or improve geometry. If you are changing ride height or alignment drastically, consider adjustable uprights. These allow for more camber adjustment without binding.
Bushings and Hardware
Polyurethane or spherical bushings replace the factory rubber to reduce deflection and improve precision. Installing bushing upgrades in control arms and sway bars tightens up the suspension feel. Use high-quality bolts and lock washers for safety. Avoid cheap hardware; suspension loads are significant.
Springs and Rate Selection
Springs are separate from coilover shocks in some setups, but most GTM coilovers use threaded spring perches. Choose springs with the correct diameter (usually 2.5-inch ID) and length. Spring rate selection depends on weight distribution: the GTM has a rear weight bias with the engine behind the driver. Softer front, stiffer rear is typical. Consult with a suspension specialist or use online calculators.
Choosing the Right Parts for Your Build
Understanding Your Goals
First, define your primary use. A street-driven GTM needs comfortable ride quality and predictable handling. A track car demands high cornering grip and adjustability. Autocross builds need quick transitions and firm damping. Your budget will also guide choices—coilovers range from $800 to $4000 per set.
Compatibility and Fitment
Factory Five designed the GTM around specific suspension dimensions. Most aftermarket parts marketed for the GTM are direct bolt-on, but double-check with the manufacturer. Some control arms require minor modifications or different brackets. Call the vendor if you are unsure.
Adjustability Levels
Not all adjustable parts are equal. Some coilovers offer only ride height adjustment, while others allow independent compression and rebound damping. For serious corner balancing, get shocks with separate adjustments. Control arms can have slotted holes for camber and caster—more adjustability means more setup time but better tuning potential.
Quality and Reputation
Stick with brands known for street and track use: QA1, Aldan, Koni, Öhlins (if budget allows), and Ground Control. Avoid no-name parts from unknown sellers. Quality shocks are built to withstand heat and abuse. Check for warranties and serviceability (rebuildable shocks last longer).
Installation Considerations
Installing suspension parts on a GTM is straightforward if you have mechanical experience. Most components bolt to the chassis with standard tools. However, setting alignment after changing parts requires precision. You will need a flat surface, camber/caster gauge, and toe plates. Many builders prefer a professional alignment shop that understands race cars.
Torque all fasteners to spec using a torque wrench. Use thread locker on critical bolts (e.g., shock mounting bolts). Grease any zerks on aftermarket control arms. After installation, cycle the suspension through full travel to check for binding.
Budget vs. Performance
Your suspension budget should reflect the total car value. For a $30,000 GTM build, spending $2000 on coilovers is reasonable. If you are building a trailer queen track car, double that. Here is a rough breakdown:
- Budget: $1000-$1500 for a basic set of adjustable coilovers (e.g., QA1 Proma Star) and stock control arms.
- Mid-range: $1500-$3000 for better shocks (Koni or Aldan) and tubular control arms.
- High-end: $3000+ for Öhlins or MCS units with multiple adjustments, plus spherical bushings and custom springs.
Don't neglect the sway bars and bushings—they are inexpensive upgrades that yield noticeable improvement.
Recommended Brands and Setup Tips
- QA1: Offers affordable, rebuildable coilovers. Their Proma Star series is popular for street and track. Spring rates available off the shelf.
- Aldan American: Known for American-made shocks with adjustable ride height and damping. Good for street/strip.
- Koni: The Koni Sport (yellow) shocks are a trusted upgrade for many cars. They improve damping control without being too harsh.
- Ground Control: Custom spring rates and coilover sleeves if you want to reuse your stock shocks or upgrade gradually.
For control arms, consider:
- Speedway Motors: Tubular arms with adjustable ball joints.
- Local race chassis builders: Some custom fabricators make arms for the GTM with better geometry.
For sway bars:
- Hotchkis: Adjustable bars with multiple attachment points.
- Addco: Solid bars with poly bushings.
A typical setup for a dual-purpose GTM: QA1 Proma Star coilovers with 450/550 springs, Speedway tubular control arms (adjustable), Hotchkis sway bars, and polyurethane bushings in all mounting points. Alignment: -1.5° front camber, -2.0° rear, 0.10° total toe-in front and rear.
Final Recommendation
For most GTM builders, a well-matched set of QA1 or Aldan coilovers, combined with upgraded control arms and sway bars, provides the best balance of performance, adjustability, and value. Start with the coilovers and sway bars—they offer the most noticeable improvement. Add control arms later if you want more alignment range or reduced weight. Do not skip bushing upgrades; they transform the feel of the car. Always prioritize quality and compatibility. If you are unsure, consult a suspension tuner who has worked on mid-engine cars. Invest in the setup time to dial in the alignment; it makes a bigger difference than any single part. With the right FFR GTM suspension parts, your car will handle like the supercar it is meant to be.