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Suspension Isn’t a Guessing Game

Suspension Isn’t a Guessing Game

Posted by Flatout Suspension on Jan 28th 2026

How Flatout Suspension Builds a Proper System From Real Data, Not Hunches

Most people think suspension tuning is mostly preference. Stiffer springs mean “sporty,” softer springs mean “comfortable,” and you just pick something in the middle and hope it works.

That’s not how we operate.

At Flatout Suspension, every kit starts with data. Hard numbers. Repeatable measurements. Real-world testing on the chassis you drive. Because when you’re building suspension for daily drivers, overlanders, rally cars, and mixed-use machines, “close enough” isn’t good enough.

A proper suspension setup is engineered, not guessed, and here’s how we do it.

1. Vehicle Weight Isn’t Optional — It’s the First Input

Weight determines everything.
Not just the curb weight you see on a spec sheet, but the actual running weight your vehicle carries:

  • factory curb mass

  • distribution front to rear

  • added accessories

  • overland load

  • passenger/cargo patterns

Why does this matter? Because a coilover doesn’t know what bumper you bolted on. A spring only knows force. Shock valving only knows velocity. If you add 250 pounds of tools in the rear or a roof rack with a spare on top, your suspension needs a different spring curve to maintain proper sag, travel, and comfort.

We start with weight because it anchors the entire setup.

2. Motion Ratios: The Hidden Multiplier Most People Miss

Every chassis multiplies or reduces effective wheel rate through suspension geometry. That multiplier, the motion ratio, dramatically changes how stiff or soft a spring feels at the wheel.

For example:

  • A 200 lb/in coilover spring on a 0.8 motion ratio doesn’t give you 200 lb/in at the tire.

  • It gives you roughly 128 lb/in of effective wheel rate.

Ignoring motion ratios is one of the biggest reasons generic lift kits ride poorly. We measure and model each chassis so we know exactly how the wheel responds to a given spring and damper setup.

3. Ride Frequency: The Science Behind “Comfortable but Controlled”

Ride frequency is the heartbeat of suspension tuning.
It’s a calculation based on sprung mass, spring rate, and motion ratio, and it tells us how quickly the body wants to oscillate.

Passenger cars and crossovers have a target frequency range from the factory that balances comfort and control. When we engineer a Flatout Suspension kit, we don’t throw that away, we build around it.

Depending on the intended use, we keep spring rates within a certain percentage of OEM frequency:

  • Daily driver comfort: typically within 0 to 15 percent of OEM

  • Heavy load / overland: slightly elevated to compensate for weight and prevent sag

  • Rally and performance: deliberately higher within a tested window for quicker response

The key is that none of this is random. Every number is tied to a frequency target we choose based on how the suspension is actually used.

4. Real-World Use Matters as Much as the Math

Data drives the foundation, but real-world use shapes the final tuning.

A Crosstrek driven on washboard gravel at speed needs a different rebound profile than a Forester carrying tools, a roof rack, and a spare. A lifted Outback Wilderness with 250 pounds of camping gear demands more low-speed support than the same car unloaded.

So after we model the setup, we adapt it based on:

  • expected load

  • surface type

  • travel goals

  • driving style

  • how the chassis behaves with additional accessories

  • expected sag targets (often ~25 percent for off-road use)

The result is a package that isn’t just mathematically correct — it’s correct for you.

5. Shock Valving and Spring Rates Work as a System

A shock isn’t tuned in isolation. Spring rate, travel, nitrogen pressure, piston design, and digressive or fluttered compression curves all influence how the suspension reacts.

So each Flatout Suspension kit is designed as a matched system:

  • Springs chosen based on weight and motion ratio

  • Valving chosen based on spring rate and intended use

  • Travel chosen to prevent bottoming under load

  • Nitrogen pressure selected for consistency and heat resistance

This is why our kits ride and handle the way customers expect: controlled, predictable, and comfortable without being vague.

6. Why This Matters for You

Anyone can bolt together random springs and dampers.
Most companies pick generic rates, claim “performance,” and call it a day.

We don’t.

When we say our GR Lite, GR Plus, or GR40 systems are engineered, we mean:

  • They maintain proper sag

  • They run the correct effective wheel rate

  • They stay within a smart and safe frequency range

  • They’re valved for the type of driving you actually do

  • They’re built to handle the loads you carry

  • They’re tested on real vehicles in the real world

That’s why Flatout Suspension kits feel planted, stable, and comfortable even over rough terrain. They’re not lucky guesses. They’re the result of real engineering.

Suspension isn’t a guessing game. Not here.

If you want a setup tailored to your vehicle, your weight, and your driving style, we’ll build the numbers and the hardware to match.

Your suspension shouldn’t be generic. It should be correct.

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