Engine Teardown

CarBahn S58 Performance Engines

Every CarBahn engine is hand-built with championship-proven racing components and over 46 years of engineering expertise from Steve Dinan, delivering extreme reliability, massive torque capacity, and road-car refinement.

Free Engine Consultation

Tell us about your build goals

to speak directly with an engine specialist.

Race-Proven Engineering

Every CarBahn engine is built using development knowledge gained from decades of BMW racing programs engineered by Steve Dinan.

Built Around Your Power Goal

Each S58 engine build is configured around your turbo system, fuel type, torque target, and intended vehicle use.

Hand-Assembled Engines

Every CarBahn engine is assembled by experienced engine builders using carefully selected internal components designed for sustained high output.

Engine Selection Guide

What's the difference between Street and Race Engines?

Every S58 build is a little different. Power goals, turbo systems, fuel type, and how the car will actually be driven all play a role in determining the right engine configuration.

In this video, Steve Dinan walks through how we approach S58 builds at CarBahn and how to think about selecting the right engine for your application — whether you're building a refined street car or a dedicated race platform.

If you're unsure which configuration is right for your build, our team can help guide the process.

Speak With an Engine Specialist
S58 Build Guide

Choosing The Right S58 Build Path

Rather than thinking in “stages,” we recommend thinking about your S58 in terms of how the car will actually be used. Most customers fall into one of three lanes: OEM+ for refined street performance, Street for more aggressive power goals, or Race for dedicated competition-focused builds.

OEM+
Road-car feel
Typical Output
~UP TO 800 WHP
Strong gains with OEM-like drivability and thermal stability.
Best For
Daily-driven M cars that need more performance without giving up refinement.
Typical Supporting Mods
ECU calibration and basic thermal support, such as a heat exchanger.
Reliability Context
Closest to OEM-style drivability and reliability expectations when paired with the right supporting hardware and tune.
Street
Higher-output builds
Typical Output
UP TO 900 WHP
For customers targeting larger power gains, ethanol blends, or upgraded turbo systems.
Best For
Serious street builds where power, response, and long-term durability all matter.
Typical Supporting Mods
Flex fuel capability, upgraded cooling, larger turbo systems, and supporting fuel system upgrades depending on target output.
Reliability Context
Still very strong, but the demands on the engine increase substantially as torque and cylinder pressure rise.
Race
Competition use
Typical Output
1000+ WHP
Intended for extreme-output applications and dedicated race programs.
Best For
Track-only or competition-oriented builds operating at sustained load and high RPM.
Typical Supporting Mods
Extensive fueling, turbo system changes, race-oriented engine management, and full competition support hardware.
Reliability Context
Built around competition use, where service intervals and rebuild expectations differ from road-car ownership.

Final build recommendations should always be based on your turbo system, fuel type, intended use, mileage, and core condition. That’s why every CarBahn S58 engine build begins with a consultation.

Built for High-Output Inline-6 Performance

Forged Internals That Let the S58 Push Harder

The S58 is an exceptionally capable performance platform, but higher boost, repeated heat cycles, sustained cylinder pressure, and elevated RPM quickly demand more than stock internals were designed to handle. CarBahn Engines address these limitations with a reinforced rotating assembly, upgraded valvetrain control, and precision oiling refinements engineered for both serious street performance and full race use.

CarBahn S58 forged connecting rods and pistons
Forged pistons and Carrillo rods form the foundation of every CarBahn S58 rotating assembly.

Whether configured for a refined street build or an all-out race application, the S58 requires a rotating assembly and valvetrain package capable of maintaining control under far greater load than the factory engine was designed to sustain. Each engine is built with application-specific components selected to balance refinement, durability, and maximum output capability.

  • 01

    Forged Pistons Engineered for Application

    Forged pistons are selected based on intended use, with street configurations utilizing offset wrist pins for reduced piston noise and improved refinement, while race configurations use centered wrist pins for maximum strength and stability under extreme cylinder pressure.

  • 02

    Carrillo Forged Connecting Rods

    These rods are designed to withstand significantly increased cylinder pressure and sustained high-output operation, giving the S58 the bottom-end strength needed for harder use, higher boost, and a much more serious power ceiling.

  • 03

    Upgraded Valve Springs for RPM Stability

    Upgraded valve springs are installed across all builds to maintain precise valvetrain control at elevated RPM. Street configurations prioritize stability and longevity, while race builds utilize higher-rate springs to ensure consistent control under extreme engine speed, boost, and sustained track load.

  • 04

    Reinforced Sealing and Bottom-End Rigidity

    Upgraded head and main studs increase clamping force and structural rigidity, while performance or racing head gaskets are selected based on application to ensure reliable sealing under elevated boost, thermal load, and repeated high-cylinder-pressure operation.

  • 05

    Compression Strategy for Power Targets

    Compression ratios are optimized based on the intended power level, with lower-compression configurations used in more aggressive race applications to support extreme boost, improved detonation resistance, and long-term durability in harsher operating conditions.

  • 06

    VANOS Oiling Refinement

    Oil passage modifications improve oil delivery under sustained load and high RPM, helping the VANOS system maintain accurate cam timing control and more consistent tracking of requested cam targets across both street and race conditions.

Upgraded high-performance valve springs

Valvetrain Control at Elevated RPM

Upgraded valve springs play a critical role in maintaining stability as engine speed and boost increase. Street builds prioritize durability and smooth operation, while race configurations utilize higher-rate springs to ensure precise control under extreme RPM and sustained load.

CarBahn S58 engines are engineered to push beyond stock limitations. Whether configured for refined street performance or full race output, each build is designed to deliver the strength, control, and consistency required at higher power levels.

S58 Engine Lineup

Choose from CarBahn’s street-focused and race-focused S58 engine configurations below.

Street Engines

Designed for high-performance road cars with strong power capability, refined drivability, and long-term durability.

Street OEM+

S58 Street OEM+

Rated up to 800 WHP / 700 WTQ

Starting at $10,995
  • Forged connecting rods
  • High-performance valve springs
  • High-performance head studs
  • VANOS oil passage modification
Street S2

S58 Street S2

Rated up to 900 WHP / 800 WTQ

Starting at $20,995
  • Forged pistons with offset wrist pins
  • Forged connecting rods
  • High-performance valve springs + head studs
  • VANOS oil passage modification
Street S3

S58 Street S3 (3.2L Stroker)

Rated up to 900 WHP / 800 WTQ

Starting at $25,995
  • 3.2L forged stroker rotating assembly
  • Forged pistons with offset pins + forged rods
  • High-performance valve springs + head studs
  • VANOS oil passage modification

Race Engines

Built for competition environments, sustained load, and maximum-output S58 applications.

Race R1

S58 Race R1

Rated 1,000+ HP / 1,000+ WTQ

Starting at $21,995
  • Forged racing pistons with centered wrist pins + forged rods
  • Racing-grade valve springs
  • Racing head and main studs + racing head gasket
  • VANOS oil passage modification
Race R2

S58 Race R2

Rated 1,000+ HP / 1,000+ WTQ

Starting at $22,995
  • R1 rotating assembly foundation
  • Racing camshafts
  • Racing head/main studs + racing head gasket
  • VANOS oil passage modification
Race R3

S58 Race R3 (3.2L Billet Stroker)

Rated 1,000+ HP / 1,000+ WTQ

Starting at $32,995
  • 3.2L billet stroker rotating assembly
  • Forged race pistons with centered pins + forged rods
  • Racing camshafts + racing valve springs
  • Racing head/main studs + racing head gasket + VANOS oil modification

S58 Engine Core Charge

$14,000

If you need a replacement S58 core, a $14,000 core charge applies. For street engine builds, a $10,000 deposit is required to begin work. Once your original core is received and inspected, that deposit will either be applied toward the purchase price or used to cover any required machining or replacement parts. For race engine builds, a 50% deposit is required at the time of order.

Refresh Kit

$2,827

The S58 Refresh Kit includes the water pump, thermostat, oil spray nozzle, timing chain, guide rail, chain tensioner, and valve lifter components. It is required for engines over 50,000 miles and recommended at 40,000+ miles to help the surrounding wear components age evenly with the new build.

BMW S58 fitment background image

What Cars Use The S58 Engine?

The BMW S58 is the current-generation twin-turbo M inline-six found across BMW’s modern M models. Below is a concise fitment guide for all factory S58 applications that our CarBahn performance engines and components are designed for.

BMW M2 / M3 / M4 (G-Series)

  • 2023–present BMW G87 M2 (RWD)
  • 2021–present BMW G80 M3 (RWD, Competition, xDrive)
  • 2021–present BMW G82 M4 Coupé (RWD, Competition, xDrive)
  • 2021–present BMW G83 M4 Convertible (Competition xDrive)

BMW X3 M / X4 M (F-Series)

  • 2019–present BMW F97 X3 M (Base & Competition)
  • 2019–present BMW F98 X4 M (Base & Competition)

If you’re unsure whether your BMW is equipped with the S58 engine, contact our team with your VIN and we’ll confirm fitment for your specific model and market.

CarBahn Engine Program

Why CarBahn S58 Engines

These are not off-the-shelf crate engines built around a generic formula. Every CarBahn S58 build is structured around the intended use of the car, target torque load, turbo system, fuel type, and long-term durability expectations.

Championship-Proven Assembly

Every CarBahn engine is built using race-informed processes and decades of BMW engine development experience engineered by Steve Dinan.

Built Around Your Power Goal

From OEM+ street builds to full race configurations, each stage is designed around a defined torque target, supporting hardware package, and real-world operating environment.

Consultation Before Order

We review your vehicle, fuel system, turbo setup, intended use, and core condition before finalizing the correct build path so the engine package matches the application.

Engine Warranty & Additional Information

CarBahn engines are engineered to support significant power levels while maintaining durability. Long-term reliability often depends on the quality of the tune and supporting components used with the engine management system.

Engines with CarBahn Software Tunes

All engines listed with a stage number (ex. Stage 1 & Stage 2) are designed to be road car engines and are covered for 2 years or 24,000 miles, provided the engine is running a CarBahn tune and no other components on the vehicle have caused a premature failure.

Engines with Another Company's Tune

Stage engines remain covered for 2 years or 24,000 miles provided the engine remains below the recommended torque limits listed on the product page. Failures caused by the tune, aftermarket fuel injection systems, or other components are not covered.

If torque limits are exceeded, warranty coverage applies only to materials and workmanship. CarBahn retains sole discretion in determining the cause of failure.

Racing Engines

Racing engines are designed for competition environments and are covered for materials and workmanship only. Racing engines should be periodically rebuilt based on runtime or mileage.

Warranty does not cover failures caused by tuning, fuel systems, or other aftermarket components. CarBahn retains full discretion in determining the cause of failure.

Engine Core Acceptance Parameters

All engines supplied for rebuilding must be a complete factory core (from oil pan to valve cover).

Block Requirements

  • No holes or cracks in casting
  • No holes or cracks in covers
  • No bore damage that cannot be honed out
  • No thrust surface damage
  • No journal surface damage
  • No bolt hole damage that cannot be repaired

Cylinder Head Requirements

  • No holes or cracks in casting
  • No holes or cracks in covers
  • No thrust surface damage
  • No journal surface damage
  • No bolt hole damage that cannot be repaired

Possible Additional Repair Charges

Additional charges may apply if the following items are damaged and cannot be serviced or repaired:

  • Valves
  • Crankshafts
  • Camshafts
  • Guides
  • Valvetronic mechanism
  • VANOS mechanism

QUESTIONS ABOUT THE PROCESS?

Common questions about CarBahn S58 engine builds, consultation, timelines, core requirements, and how we help match the right configuration to your goals.

How do I know which S58 build is right for me? +

The right build depends on how you use the car, your target power level, your turbo system, fuel type, and how much torque you plan to carry over time. Our consultation process helps determine whether an OEM+, S2, S3, or one of the race engine configurations is the best fit.

Do I need to send in my original engine core? +

In most cases, yes. If you are supplying a usable core for a street engine build, a $10,000 deposit is required to begin work. Once your engine is received and inspected, that deposit is either applied to the purchase price or used to cover any required machining or replacement parts.

If you need a replacement S58 core instead, a $14,000 core charge applies.

What happens if my engine core has damage? +

Your core must meet CarBahn’s acceptance standards. If inspection reveals damage that requires machining, replacement parts, or repair work beyond a typical overhaul, those costs are deducted from the deposit or billed accordingly.

Common examples of additional-charge items include valves, crankshafts, camshafts, guides, Valvetronic components, and VANOS components when they cannot be serviced or repaired.

How long does an S58 engine build usually take? +

Build timing depends on engine configuration, parts availability, machine work requirements, and current production scheduling. Street and race builds can vary significantly depending on scope.

The best way to get an accurate timeline is to submit the consultation form or call the team directly so we can review your target setup and current core situation.

Do I need the refresh kit? +

The Refresh Kit is required for engines over 50,000 miles and recommended at 40,000+ miles. It includes the water pump, thermostat, oil spray nozzle, timing chain, guide rail, chain tensioner, and valve lifter components.

This helps ensure the surrounding systems and wear items can age evenly with the fresh internal build.

What tune should I run with a CarBahn stage engine? +

CarBahn stage engines are designed around defined power and torque targets. For the strongest street warranty position, we recommend running a CarBahn tune.

If you run another company’s tune, warranty terms still depend on staying within the recommended torque limits shown on the product listing, and failures caused by the tune or related aftermarket fuel components are not covered.

Are race engines covered under warranty? +

Race engines are built for competition use and are covered for materials and workmanship only. They should be rebuilt periodically based on runtime or mileage.

Failures caused by tuning, aftermarket fuel systems, or other related components are not covered, and CarBahn retains full discretion in determining the cause of failure.

Can I use these engines on a California road car? +

Racing engine configurations must carry the following statement: NOT LEGAL FOR SALE OR USE IN CALIFORNIA ON ANY POLLUTION CONTROLLED MOTOR VEHICLE

If you are building a street-driven vehicle and need help selecting a compliant path for your intended use, contact the CarBahn team before ordering.

Still have questions? Submit the consultation form or call (866) 558-4314 x1 to speak with an engine specialist.