4TH GEAR PERFORMANCE / DALLAS, GEORGIA

S-CHASSIS SERVICE & PERFORMANCE

S13 · S14 · S15

Your chassis is a starting point. We look at what is installed, its condition and your goals to plan maintenance, repairs and upgrades around the car you have today.

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THREE GENERATIONS. INDIVIDUAL COMBINATIONS.

Choose Your Chassis

S13CA18DE/DET · SR20DE/DET · KA24E/DES14SR20DE/DET · KA24DES15SR20DE/DET

Explore S13

01 / 04OVERVIEW
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Nissan S13

01 / OVERVIEW

S13

S13 / EARLIER GENERATION / CURRENT SETUP FIRST

The S13 generation includes different market specifications and body styles. A long history of ownership can matter as much as its original badge. Identify the installed engine, transmission and supporting hardware before choosing a service or upgrade path.

Engine bay of this Nissan S13; configurations vary between individual cars

02 / SERVICE NEEDS

START WITH A MECHANICAL BASELINE

Before recommending repairs or upgrades for your S13, we establish its configuration, previous changes, current condition, and which systems need attention.

Identify what is installed — Confirm the engine, transmission, fuel and cooling configuration, including any documented swap work.

Review age and integration — Evaluate hoses, wiring, mounts and earlier repairs where condition or symptoms warrant.

Connect the chassis systems — Check steering, bushings, hubs, brakes and drivetrain concerns in the context of street or track use.

S13 driving on a drift course

03 / UPGRADE PATHS

BUILD TOWARD A DEFINED GOAL

A street refresh, a sharper performance car, and a larger build should not follow the same path. We match each change to how you want the car to perform and what the rest of the vehicle can support.

Street Refresh

Review service history, address leaks and cooling needs, then prioritize steering, bushings, brakes and drivetrain wear.

Street Performance

Match suspension, brake, differential and cooling improvements to the actual engine and the owner’s street or track goals.

High Performance

Plan the installed or proposed engine with fuel, cooling, clutch, transmission, driveshaft, differential and chassis support as a complete combination.

Detail view of the Nissan S13

04 / FAQ

S13 questions, answered.

I bought an S13 with an unknown modification history. Where do we start?

Bring any records, parts lists and symptoms you have. We start by identifying the current hardware and condition, then agree on the checks needed to fill the gaps.

Can you assess an engine-swapped S13?

Share the engine, transmission and known swap details first. We can discuss diagnosis and supporting-system needs, then confirm the scope for that particular combination.

Does drift history change the inspection priorities?

Usage and symptoms help set priorities. Steering, suspension, hubs, brakes and drivetrain may warrant closer attention, but previous track use alone does not establish a fault.

Can I refresh an S13 for street use without building a drift car?

Yes. The plan can focus on dependable maintenance, comfortable suspension behavior, braking and the existing drivetrain. The intended use guides the choices.

Explore S14

01 / 04OVERVIEW
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Nissan S14

01 / OVERVIEW

S14

S14 / MIDDLE GENERATION / VERIFY FITMENT

The S14 followed the S13 with a different coupe body and its own fitment considerations. Market, year and subsequent changes all affect the combination underneath. We verify the present powertrain and chassis hardware rather than order parts from the chassis code alone.

Rear view of a modified S14, showing this vehicle’s body and wheel setup

02 / SERVICE NEEDS

START WITH A MECHANICAL BASELINE

Before recommending repairs or upgrades for your S14, we establish its configuration, previous changes, current condition, and which systems need attention.

Understand the driveline — Identify the transmission, clutch, driveshaft and differential combination before investigating noises or drivability concerns.

Check chassis compatibility — Review suspension, steering, hubs, wheel clearance and brake conversions where fitted.

Follow the evidence — Maintenance history, fluid condition, leaks and the quality of system integration determine the next checks.

Modified Nissan S14

03 / UPGRADE PATHS

BUILD TOWARD A DEFINED GOAL

A street refresh, a sharper performance car, and a larger build should not follow the same path. We match each change to how you want the car to perform and what the rest of the vehicle can support.

Street Refresh

Restore a dependable baseline by addressing overdue fluids, cooling needs, worn mounts and chassis components that inspection identifies.

Street Performance

Improve braking, suspension and differential behavior around the current driveline, with compatible supporting hardware and street or track priorities.

High Performance

Build the plan around how engine output, heat, fuel delivery and driveline loads affect the brakes, suspension and chassis combination.

Closer rear detail of the modified S14

04 / FAQ

S14 questions, answered.

My S14 has parts from other generations. Is that a problem?

Not automatically. Identify the parts and how they are installed, then check compatibility, clearance and operation. A mixed combination should be assessed on its actual condition.

Can you evaluate the suspension and differential already fitted?

Tell us the parts you know, how you use the car and what you want to change. The existing setup and any symptoms guide an appropriate assessment.

Should I replace previous-owner work before upgrading?

Replacement is not the starting assumption. We first understand the installation and its condition, then explain any repairs or supporting changes the proposed upgrade needs.

What information helps with an S14 driveline concern?

Bring details of the engine, transmission, clutch, driveshaft and differential if available. Describe when the noise or vibration occurs and any recent work.

Explore S15

01 / 04OVERVIEW
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Side view of a Nissan S15

01 / OVERVIEW

S15

S15 / LATER SILVIA GENERATION / HISTORY MATTERS

The S15 is the later Silvia generation, with its own body, trim and mechanical configurations. Imported and modified examples need an individual approach: records, identification and inspection establish what is fitted today and how it supports the owner’s goals.

Rear view of a Nissan S15, showing this individual vehicle’s exterior setup

02 / SERVICE NEEDS

START WITH A MECHANICAL BASELINE

Before recommending repairs or upgrades for your S15, we establish its configuration, previous changes, current condition, and which systems need attention.

Confirm specification and history — Establish the current engine and transmission, service records and any imported or replacement hardware.

Review supporting systems — Evaluate cooling, fuel delivery and electrical integration according to the installed setup and symptoms.

Match checks to use — Assess steering, suspension, brakes, hubs and driveline where wear, earlier preparation or current behavior calls for it.

Nissan S15 on a drift course

03 / UPGRADE PATHS

BUILD TOWARD A DEFINED GOAL

A street refresh, a sharper performance car, and a larger build should not follow the same path. We match each change to how you want the car to perform and what the rest of the vehicle can support.

Street Refresh

Identify current service needs and address age-related wear in cooling, fluids, mounts, brakes and chassis components before adding more hardware.

Street Performance

Balance suspension, steering, brakes and driveline changes with the existing engine and cooling setup for the desired road or track behavior.

High Performance

Agree on the intended use, then coordinate engine, fuel, cooling, transmission, clutch, driveshaft, differential and chassis requirements.

Closer side detail of the Nissan S15

04 / FAQ

S15 questions, answered.

Can you discuss service for an imported S15?

Yes. Share the vehicle identification, available records, installed powertrain and concerns. We confirm the service scope and parts requirements for that individual car.

Should an S15 still have its original engine and transmission?

Do not assume it does. Previous changes and replacement parts may differ from the original specification; the actual hardware needs to be identified.

Does an S15 need drift-oriented upgrades?

No. The plan can prioritize street reliability, comfort, braking or another intended use. Action photography does not define what your car should become.

What should come before a larger S15 performance project?

Understand current condition, parts compatibility and the existing supporting systems. Address relevant repairs and maintenance, then plan the larger combination around your goals.

COMPLETE-CAR SERVICE

S-CHASSIS SERVICE, FROM BASELINE TO BUILD.

Maintenance, diagnostics, repair, and performance work approached with the engine, cooling, drivetrain, brakes, suspension, and chassis in context.

  • Maintenance
  • Diagnostics
  • Engine repair
  • Cooling systems
  • Fuel systems
  • Turbo & exhaust where applicable
  • Suspension
  • Brakes
  • Clutch & drivetrain
  • Performance upgrades
  • Mechanical refresh
  • Wiring & electrical diagnosis
  • Steering
  • Differential

DEFINE THE OUTCOME

WHAT DO YOU WANT THE CAR TO DO?

01

Maintain It

Keep the car healthy, reliable, and current on the service that protects it.

02

Refresh It

Correct age, wear, deferred maintenance, and previous work so the car feels right again.

03

Upgrade It

Improve performance with changes chosen to work with the car's current configuration.

04

Build It

Plan a larger combination by matching the performance goal with the fuel, cooling, drivetrain, braking, and chassis support it needs.

Engine bay of an S13, showing the configuration of this individual car

BASELINE BEFORE UPGRADES

UNDERSTAND THE CAR YOU ACTUALLY HAVE.

On an S-Chassis, the chassis code rarely tells the whole story. Engine swaps, wiring changes, mixed driveline components, suspension conversions, and decades of previous work can completely change what the car needs.

We identify the combination that's actually in front of us first. Then we can separate maintenance from problems, preserve the parts that already work, and build a reliable path toward what you want the car to become.

Discuss your starting point
Modified S14 photographed as an example of an individual S-Chassis setup

PARTS THAT FIT THE PLAN

THE RIGHT PART SHOULD MAKE THE WHOLE CAR BETTER.

Good parts choices start with the exact vehicle, the hardware already installed, and what you're trying to accomplish. We use fitment and the larger plan to connect the part to the system around it.

SHOP S CHASSIS PARTS

HOW WE WORK

A CLEAR PATH FROM ASSESSMENT TO EXECUTION.

  1. 01

    TELL US ABOUT THE CAR

    What it is, what has been changed, what it's doing, and what you want from it.

  2. 02

    UNDERSTAND THE SETUP

    We verify the configuration, condition, service history, and previous work that matter to the job.

  3. 03

    DEFINE THE WORK

    We prioritize maintenance, repairs, and upgrades in the order that makes sense.

  4. 04

    EXECUTE THE PLAN

    We complete the agreed work with the supporting systems and end goal in mind.

WHY 4TH GEAR

PLATFORM KNOWLEDGE. WHOLE-CAR THINKING.

4th Gear combines a focused approach to Nissan, Infiniti, Supra, and modified JDM platforms with a systems-based approach to service and performance. We diagnose before replacing parts, account for the work that's already been done, and plan around how the engine, fuel, cooling, drivetrain, brakes, suspension, and chassis work together.

The goal isn't to put more parts on the car. It's to make the car better at what you want it to do.

BUILD THE PLAN AROUND THE CAR YOU ACTUALLY HAVE.

S13, S14 or S15: start with the current setup, define the goal and move forward from a solid baseline.

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