Introduction: Unlocking the Lexus IS500's True Potential

The Lexus IS500 F Sport Performance arrives from the factory with a naturally aspirated 5.0-liter V8 producing 472 horsepower and 395 lb-ft of torque. While that makes it the most powerful IS ever offered, the engine—the venerable 2UR-GSE—has significant untapped headroom. Enthusiasts seeking to push beyond OEM limits have turned to forced induction, with the Garret GTX3584RS turbocharger emerging as a top candidate. A well-engineered turbo kit using this turbo can deliver over 100 rear-wheel horsepower gains for a parts investment of roughly $5,500. This article provides an in-depth look at the turbocharging process, the components involved, installation considerations, and what owners can realistically expect in terms of performance, cost, and reliability.

The 2UR-GSE Engine: A Naturally Aspirated Powerhouse

The Lexus IS500 shares its engine architecture with the RC F and GS F. The 2UR-GSE is an all-aluminum, 32-valve V8 featuring dual independent Variable Valve Timing (VVT-iE) on the intake side and D4-S direct injection combined with port injection. The high compression ratio (11.8:1) and Yamaha-developed cylinder heads contribute to its free-revving nature and linear power delivery. However, the stock induction and exhaust systems are restrictive, and the ECU is calibrated for emissions and drivability rather than peak output. Forced induction addresses these limitations by increasing air density, but the high compression ratio requires careful tuning and often a lower static compression or water-methanol injection for safe boost levels. The 2UR-GSE's closed-deck block and forged steel crankshaft offer a robust foundation, but the factory pistons and rods—while strong—become a limiting factor beyond a certain power level.

Turbocharging vs. Supercharging: Why a Garrett GTX3584RS?

For the IS500, forced induction options include centrifugal supercharger kits and turbocharger systems. Superchargers offer immediate boost response and a linear power curve, but they also create parasitic drag and can be limited in top-end flow. Turbochargers, on the other hand, convert exhaust energy into pressure, allowing for higher peak power potential and often superior mid-to-high RPM performance. The Garret GTX3584RS is a ball-bearing turbocharger that bridges a gap between quick spool and massive airflow:

  • Compressor Inducer/Exducer: 58mm inducer, 84mm exducer wheel with GTX dual-port technology for reduced backflow and higher efficiency.
  • Turbine: 68mm turbine wheel with low-inertia design for faster spool without sacrificing top-end flow.
  • Power Capability: Rated to support over 700 horsepower in automotive applications, providing a substantial safety margin for 550-650 wheel horsepower targets.
  • Ball Bearing Core: Reduces friction and oil volume requirements compared to journal bearings, improving transient response.

For comparison, a typical supercharger kit for the 2UR-GSE might add 90-120 horsepower at the wheels, but a properly sized turbo system like the GTX3584RS can deliver 130-170 wheel horsepower gains with the right supporting modifications. The spool time is well-managed—full boost can arrive as early as 3,200-3,500 RPM when paired with a correctly sized turbo manifold and downpipe.

Components of a Complete Turbo Kit

A $5,500 turbo kit for the Lexus IS500 (or RC F, GS F with minor variations) should include all necessary parts for a bolt-on or semi-custom installation. While some systems are sold as "kits" from vendors like RR Racing or custom fabricators, the core components typically include:

  • Garret GTX3584RS Turbocharger Core – The heart of the kit.
  • Cast or Fabricated Turbo Manifold – Designed to fit the 2UR-GSE exhaust ports; usually equal-length stainless steel or schedule 40 mild steel.
  • Wastegate – External 44mm or 50mm unit (Tial or Turbosmart) for boost control.
  • Blow-Off Valve – Required to release pressure between shifts and protect the compressor wheel.
  • Air-to-Air or Air-to-Water Intercooler – A 3” or 3.5” core sized for the power target; placement is often in the lower bumper trim with custom ducting.
  • Mandrel-Bent Aluminum Piping – From turbo compressor to intercooler to throttle body.
  • Downpipe and Exhaust System – A 3” downpipe merging into the cat-back; provisions for O2 sensors.
  • Oil and Coolant Lines – Braided stainless steel lines with AN fittings for turbocharger lubrication and cooling.
  • Intake and Filter – A high-flow cone filter with heat shield to avoid drawing hot engine air.
  • Gaskets, Hardware, and Clamps – Necessary for sealing and assembly.

Additional parts that may not be included but are strongly recommended: upgraded fuel injectors (e.g., Fuel Injector Clinic 850cc-1000cc), a higher-flow fuel pump (Walbro 525 or similar), and a boost controller with map sensor integration for the ECU tune.

Installation Walkthrough: What to Expect

While the IS500 engine bay offers decent access, installing a turbo kit is a major job that typically takes 30-50 hours for an experienced mechanic. The process involves significant disassembly and custom fitting:

Preparation and Disassembly

  • Disconnect the battery and drain the coolant and oil.
  • Remove the front bumper, radiator fan shroud, intake manifold, exhaust manifolds, and OEM air filtration system.
  • Remove the catalytic converters and lower exhaust system to provide clearance for the downpipe.

Turbo Mounting and Piping

  • Install the turbo manifold onto the cylinder heads. Torque the bolts to spec (typically 30-35 lb-ft in sequence).
  • Mount the GTX3584RS to the manifold using provided gaskets and hardware.
  • Attach the wastegate and blow-off valve; route vacuum lines to the boost controller.
  • Position the intercooler and measure custom piping routes. The 2UR-GSE engine has tight clearances near the driver’s side strut tower—be prepared to trim or modify piping for proper fitment.
  • Connect oil feed line from an oil pressure port (often at the top of the engine near the camshaft) and oil drain line to the oil pan. Coolant lines can be tee'd into the heater core loop.

Fuel System Upgrades

  • Replace fuel injectors with larger units matched to the desired fuel flow (gasoline or E85).
  • Install a fuel pump controller or upgrade the in-line pump to handle increased demand.
  • If using E85, upgrade fuel lines and ensure compatibility with the flex-fuel sensor if desired.

Reassembly and Final Checks

  • Reinstall intake manifold with new gaskets; bolt on the throttle body with the new intercooler piping.
  • Reconnect all vacuum lines, hoses, and electrical connectors.
  • Fill oil and coolant, bleed the system, and check for leaks.
  • Reattach the front bumper and cooling fans, ensuring adequate intercooler airflow.

Tuning: The Critical Step for Safe Power

No turbo kit can deliver gains without a proper ECU calibration. The Lexus IS500 uses a proprietary ECU that is not easily reflashed like some European counterparts. Options include:

  • ECUTek or Delicious Tuning Piggyback – A common solution that intercepts sensor signals to adjust fuel and timing. Requires a professional tuner with 2UR-GSE experience.
  • Standalone ECU – MoTec or Haltech units offer full control but require extensive harness modifications and cost >$3,000 plus mapping.
  • Fueling Adjustments – The stock ECU can often handle modest boost with a piggyback, but for over 550 wheel horsepower, direct injection timing and port fuel trim become critical. Professional tuning on a chassis dynamometer is non-negotiable to avoid knock damage.

Target boost pressure for the GTX3584RS on pump gas (93 octane) is typically 7-9 psi, yielding around 580-620 wheel horsepower. With E85 and higher boost (12-14 psi), 680-720 wheel horsepower is achievable, though the factory pistons become a weak point beyond 650 wheel horsepower consistently.

Expected Results: Dyno Gains and Real-World Performance

On a mustang dyno, a well-tuned IS500 with the Garret GTX3584RS kit (including fuel upgrades and exhaust) can produce:

  • Stock Baseline: ~400 hp at the wheels (SAE correction).
  • Turbocharged (93 octane, 8 psi): ~530-560 wheel horsepower; ~480-510 lb-ft torque.
  • Turbocharged (E85, 11 psi): ~600-630 wheel horsepower; ~550-580 lb-ft torque – a gain of over 200 wheel horsepower.

Even the conservative 8 psi tune provides a significant improvement in acceleration: 0-60 times drop from 4.4 seconds to the mid-3.5-second range, and quarter-mile traps increase from 113 mph to 125+ mph. The power delivery remains linear with minimal lag, as the GTX3584RS is sized to spool efficiently on a 5.0-liter V8.

For reference, a build thread on Club Lexus documents a similar installation with video evidence of back-to-back dyno pulls. The Garrett website provides official specifications for the GTX3584RS: Garrett Motion GTX3584RS.

Cost Breakdown: Budgeting for Boost

The $5,500 figure for the turbo kit typically covers the turbocharger, manifold, wastegate, BOV, intercooler, and piping. However, a complete installation budget should include:

  • Turbo Kit Parts: $5,500 – includes all major components as listed above.
  • Fuel System Upgrades: $800-1,500 (injectors, pump, lines).
  • ECU Tuning and Software: $1,500-2,500 (piggyback, dyno time, tuning fees).
  • Labor (if not DIY): $2,000-3,500 (30-50 hours at $60-100/hr).
  • Miscellaneous (gaskets, fluids, heat wrap, boost controller): $400-800.

Total investment: $10,000-$13,500 for a fully functional, reliable turbo system. While $5,500 for the kit alone is an entry point, skimping on fuel system or tuning can lead to engine damage. Many owners choose to install the kit themselves to save labor costs, but professional tuning remains essential.

Reliability and Maintenance Considerations

Adding a turbocharger to any high-compression engine requires diligence. Key points for longevity:

  • Heat Management: The exhaust gas temperatures (EGTs) can rise with boost. Ceramic coating the manifold and downpipe helps, along with turbo blanket installation.
  • Oil Quality: Use a high-performance synthetic oil (0W-40 or 5W-40) and change it every 3,000-4,000 miles. The turbo bearings rely on clean oil.
  • Coolant Circulation: Consider an upgraded radiator and electric fan controller to maintain operating temperatures during track use.
  • Inspection Intervals: After the initial tune, monitor fuel trims, knock retard, and boost levels. A catch can in the PCV system prevents oil blowby from entering the intake.
  • Fuel Quality: Always use top-tier fuel with adequate octane. Forced induction on minimum octane reduces margin for knock.

With proper maintenance, a turbocharged IS500 can be a daily driver. Many owners report thousands of trouble-free miles. However, abuse from continuous high-boost runs without proper cooling can shorten component life. The factory transmission (the Aisin AA80E eight-speed automatic) is robust and handles up to 700 lb-ft with minimal issues, though a transmission cooler is recommended for track use.

Conclusion: Is the $5,500 Turbo Kit Worth It?

The Garret GTX3584RS turbocharger kit presents a compelling upgrade path for the Lexus IS500. For just over $5,000 in parts—and a total outlay of $10,000-$13,500 with supporting modifications—owners can achieve a transformed driving experience with 100-200 extra wheel horsepower. The kit’s power ceiling far exceeds that of a supercharger, and the ball-bearing turbo provides brisk spool characteristics that complement the 5.0-liter V8’s character. Installation is not a weekend project for a beginner, but the results are measurable and adrenaline-fueling. For anyone looking to elevate their IS500 from a luxury cruiser to a serious contender against compact supercars, this turbo kit is a practical and proven solution. Always source components from reputable suppliers and consult with a tuner experienced in 2UR-GSE forced induction to ensure a safe and high-performing build.

For more information, refer to the official Garrett Motion product page and the IS F/500 technical discussion community on Club Lexus for real-world build logs and dyno results.