Cost Breakdown: Building a 700 Hp Sc300 2jz with Garrett Gtx Turbo and Aftermarket Internals

Building a 700‑Horsepower Lexus SC300: The Complete Cost Breakdown for a 2JZ‑GTX Build

The Lexus SC300, with its nearly bulletproof 2JZ‑GE engine and rear‑wheel drive layout, has long been a favorite among enthusiasts seeking a high‑horsepower street machine. Swapping in a 2JZ‑GTE or building the existing block to handle 700 wheel horsepower while adding a Garrett GTX turbocharger and forged internals is a proven path, but the costs can quickly spiral without a clear plan. This expanded guide breaks down every major expense—from the long block and turbo system to fuel delivery, engine management, and labor—so you can budget realistically and avoid costly surprises.

Why 700 Horsepower Is the Sweet Spot

Building a 2JZ to 700 hp strikes a balance between daily drivability and serious performance. The engine architecture supports this power level with moderately upgraded internals, a single large turbo, and a properly tuned standalone ECU. Beyond 800 hp, you begin to chase diminishing returns with sleeved blocks, billet cranks, and every supporting system pushed to the limit. For most street‑driven SC300s, 700 hp offers exhilarating acceleration without requiring a dedicated race budget.

1. The Foundation: Engine Block and Cylinder Head

Your starting point matters. A 2JZ‑GTE (twin‑turbo) block from a Supra or Aristo comes with oil squirters and stronger main caps. A 2JZ‑GE block (as found in the SC300) can be used but often demands additional machine work. Here are the costs for each path:

2JZ‑GTE short block (used, core): $1,500–$2,500
2JZ‑GE block (machine work for forged internals): $500–$1,000 (includes hot tank, bore, and deck)
OEM head gasket (composite): $150–$250 (upgrade to MLS if boosting over 25 psi)
Head studs (ARP L19): $350
Cylinder head refresh (valve job, seals, springs): $600–$1,000

If you start with a used 2JZ‑GTE long block, plan on $3,000 to $4,000 for a complete rotating assembly ready for forged internals.

2. Forged Aftermarket Internals

To survive 700 hp and potential 30+ psi boost, the rotating assembly must be upgraded. The stock 2JZ crankshaft is good for 700–800 hp, but rods and pistons are the weak links. Below is a realistic pricing breakdown for name‑brand components:

Pistons

CP‑Carillo or JE forged pistons (86.5 mm bore): $600–$750
Wiseco pistons (same spec): $550–$650

Connecting Rods

Manley H‑beam rods: $650–$750
Pauter or Carrillo billet rods: $1,000–$1,300

Crankshaft

Stock 2JZ crankshaft (reconditioned): $300–$500 (if you already have one)
Aftermarket billet crankshaft (e.g., Eagle, Brian Crower): $1,200–$1,800

Bearings, Rings, and Machine Work

Main and rod bearings (Clevite or ACL): $200–$300
Piston rings (file‑fit): $100–$150
Machine shop (balance, bore, hone): $500–$800

Total for aftermarket internals (pistons, rods, bearings, machine work, rings): $2,500–$3,500 depending on brand and whether you reuse the stock crank.

3. Garrett GTX Turbocharger System

The Garrett GTX series—particularly the GTX3576R, GTX3582R, or GTX3584R Gen II—are ideal for 700 hp on a 2JZ. They spool quickly and deliver top‑end power without sacrificing response. You will also need the supporting hardware for mounting and wastegate control.

Garrett GTX3582R Gen II (ball bearing): $1,600–$1,900
Turbo manifold (stainless steel, divided T4 or T3 twin scroll): $600–$1,200
Tial or Turbosmart 44 mm wastegate: $350–$450
Tial Q blow‑off valve (50 mm): $250–$300
Front‑mount intercooler (3” core, 2.5” outlets): $400–$700
Intercooler piping (mandrel bent aluminum kit): $250–$400
Turbo blanket, oil/coolant lines, gaskets: $300–$400

Total for turbocharger and supporting mods: $3,500–$4,500 if you buy quality parts and a name brand manifold.

4. Fuel System Upgrades

700 hp requires approximately 80–100 lb/hr of fuel per injector at 3 bar base pressure (depending on duty cycle and pump voltage). A full return‑style fuel system is strongly recommended for consistency.

Injectors

Injector Dynamics ID1050x (1050 cc/min): $700–$800
Bosch 2200 cc (for flex fuel): $600–$750

Fuel Pump and Lines

Walbro 525 or AEM 380 in‑tank pump: $200–$300
Secondary surge tank/auxiliary pump (for e85): $300–$500
AN‑8 feed and AN‑6 return lines (full kit): $200–$350
Fuel rail (aftermarket billet, e.g., Radium): $300–$500
Fuel pressure regulator (Aeromotive A1000): $200–$300

Total fuel system expense: $1,500–$2,500 depending on whether you run a single pump or a complete surge system.

5. Engine Management and Tuning

No 700 hp build will succeed without a standalone ECU. The 2JZ is well served by a few popular options. Wiring and tuning add significant cost.

Haltech Elite 1500 (plug‑and‑play for SC300): $1,500–$1,700
AEM Infinity 506 (with harness): $1,600–$2,000
Link G4+ Fury (wiring specialist optional): $1,300–$1,500
Wideband O2 sensor (often included with ECU): $150–$250
Professional dyno tuning session (on pump gas or e85): $500–$800
Wiring harness modification (if not plug‑and‑play): $400–$700

Total for ECU and tuning: $2,000–$3,000 (assuming a plug‑and‑play unit and one tuning session).

6. Supporting Systems: Cooling, Exhaust, and Intake

Cooling

Dual‑pass or CSF radiator (all aluminum): $400–$600
SPAL or Flex‑a‑lite electric fans (dual): $200–$350
Oil cooler kit (Setrab, 19‑row core): $300–$500

Exhaust

Custom 3‑inch downpipe with flex section: $300–$500
Full 3‑inch exhaust (stainless steel, resonator + muffler): $600–$1,000

Intake

3‑inch aluminum intake pipe with filter: $100–$200
Air filter (K&N, AEM, or equivalent): $60–$100

Total for supporting mods: $1,600–$2,600.

7. Drivetrain Upgrades

700 hp will destroy stock SC300 drivetrain parts quickly. You need a clutch, transmission, and differential that can handle the torque.

R154 transmission (used, rebuilt with stronger bearings): $1,200–$2,000
Clutch (twin‑plate from South Bend, ACT, or Competition Clutch): $1,000–$1,500
Aluminum flywheel (12‑15 lb): $350–$500
Driveshaft (custom 1‑piece): $400–$600
Differential (Supra LSD rebuild or Ford 8.8 swap): $800–$1,500

If you keep the stock A340E automatic, budget for a built valve body, torque converter, and trans cooler ($1,500–$2,500). Typical drivetrain budget: $3,000–$5,000.

8. Labor Costs

Labor rates vary by region ($100–$180 per hour). Having a professional shop assemble the short block, install the turbo system, and wire the ECU can add up fast. Below is an honest estimate for a shop doing the work (assuming you supply all parts):

Engine machining and short block assembly (by machine shop): $800–$1,200
Engine removal and installation (R&R plus accessories): $1,200–$1,800
Turbo system, exhaust, and intercooler fabrication/install: $1,000–$1,500
Fuel system plumbing and wiring: $600–$1,000
ECU wiring and base map (if not plug‑and‑play): $500–$800
Dyno tuning session (full day): $500–$800

Total labor (professional shop): $5,000–$7,000. A do‑it‑yourself builder can save $2,000–$3,000 in labor, but machine shop and tuning fees remain.

9. Budget Summary: Full Cost Estimate

Combining the categories above, here is the complete cost range for building a 700 hp SC300 with a 2JZ and Garrett GTX turbo:

Category	Low Estimate	High Estimate
Engine block and cylinder head (with machine work)	$3,000	$5,000
Aftermarket internals (pistons, rods, bearings, rings)	$2,500	$3,500
Turbocharger system (GTX, manifold, wastegate, intercooler)	$3,500	$4,500
Fuel system (injectors, pump, lines, regulator)	$1,500	$2,500
Engine management + tuning	$2,000	$3,000
Cooling, exhaust, intake	$1,600	$2,600
Drivetrain (clutch, transmission, differential)	$3,000	$5,000
Labor (full professional build)	$5,000	$7,000
Total Estimated Cost	$22,100	$33,100

Note: The original article’s $13,250 estimate covers only the engine, turbo, fuel, ECU, and labor for an engine build. When you factor in drivetrain, cooling, and professional machine work, the realistic total for a complete, driveable 700 hp SC300 is $20,000–$33,000. If you do all labor yourself (except machine work and tuning), you can reduce that to around $15,000–$18,000.

10. Where to Find Parts and Save Money

Used parts: Check Supraforums and Club Lexus classifieds for 2JZ blocks, used Garrett turbos, and aftermarket manifolds.
Budget brands: Consider K1 Technologies rods or Wiseco pistons for good quality at a lower price point than top‑tier billet options.
DIY wiring: Use a pre‑terminated harness from Haltech or AEM to avoid expensive wiring labor.
Local machine shop: Build a relationship with a shop that knows 2JZ engines; they can often source parts at wholesale.

11. Final Thoughts

Building a 700 hp SC300 with a 2JZ and Garrett GTX turbo is a fantastic goal that offers real street credibility and track capability. The cost breakdown above shows that while the engine itself might be $5,000–$7,000, a complete, reliable car requires budgeting for drivetrain, cooling, and labor. Plan for $20,000–$25,000 as a realistic budget for a well‑executed build on pump gas, and add $2,000–$3,000 more if you want e85 flexibility. Invest in quality parts from name brands like Garrett, CP, Manley, and Injector Dynamics, and don’t cut corners on tuning—an extra $500 on a proper dyno session will save you from a $5,000 rebuild down the road.

For additional reading on 2JZ‑GTE power levels and builds, check out Suprasd.com’s 2JZ Power Guide or visit Garrett’s official 2JZ tuning page. With careful planning and a thoughtful parts selection, your 700 hp SC300 will be a build you’ll enjoy for years.