Why the SR20DET for a Datsun 510?

The Datsun 510, often called the "poor man's BMW," is a lightweight, rear‑wheel‑drive sedan with a chassis that responds beautifully to more power. The stock L‑series engine, while reliable, struggles to reach even 150 hp without extensive work. Dropping in a Nissan SR20DET—a turbocharged 2.0‑liter four‑cylinder from the S13–S15 Silvia—gives you a modern engine with a proven aftermarket, robust iron block, and easy 200+ hp potential on stock internals. It’s a swap that transforms the 510 from a fun cruiser into a genuine performance car.

But the swap isn’t cheap, and costs can spiral if you don’t plan carefully. Below we break down every major component, the realistic price range you should expect, and the hidden costs that often catch first‑time swappers off guard.

Budgeting for the Swap: A Detailed Cost Breakdown

Prices are based on current market conditions (2024‑2025) from reputable suppliers, salvage yards, and enthusiast forums. Your location and the condition of components will shift these numbers.

1. Engine Purchase

The heart of the swap. A complete SR20DET includes the engine, turbo, intake manifold, exhaust manifold, and often the alternator and power‑steering pump. “Front clip” deals (whole front of a donor car) can be cheaper but add shipping.

  • Used stock SR20DET (80k–120k miles): $1,500 – $3,000
  • Rebuilt or low‑mileage JDM engine: $3,000 – $5,000
  • Long block only (no turbo, manifolds, accessories): $800 – $1,500

Tip: Always compression‑test a used engine before buying. A tired SR20 can still hit 200 hp, but reliability suffers.

2. Transmission

The SR20DET typically mates to a FS5W71C five‑speed. The 510’s original transmission won’t bolt up. You also need the correct clutch and throwout bearing.

  • Used SR20DET 5‑speed transmission: $500 – $1,000
  • Rebuilt unit with new synchros: $1,200 – $1,800
  • Aftermarket performance transmission (e.g., CD009 conversion): $1,500 – $3,500

3. Engine Mounts and Crossmember

You’ll need custom mounts to fit the SR20 into the 510’s engine bay. Most kits use polyurethane bushings and billet aluminum brackets.

  • Custom engine‑mount kit: $200 – $500
  • Modified or custom crossmember (if needed): $100 – $300

4. Wiring Harness and ECU

The SR20’s engine harness must be adapted to the 510’s body. A stand‑alone wiring harness from specialists like Wiring Specialties makes installation plug‑and‑play.

  • Modified OEM harness (by a pro): $300 – $600
  • OEM Nissan ECU (stock or chipped): $200 – $500
  • Stand‑alone ECU (Megasquirt, Haltech, Link): $900 – $1,800

5. Fuel System Upgrades

To hit 200+ hp reliably, the stock 510 fuel system is woefully inadequate. You’ll need a high‑flow pump, larger injectors, and an adjustable regulator.

  • Fuel pump (Walbro 255 or equivalent): $100 – $300
  • Fuel injectors (550‑770cc for 200‑250 hp): $200 – $500
  • Adjustable fuel‑pressure regulator: $100 – $200
  • Hardware (lines, filters, fittings): $100 – $300

6. Exhaust System

A free‑flowing exhaust is critical for spooling the turbo and reducing backpressure. The 510’s stock exhaust routing may need to be modified around the rear crossmember.

  • Aftermarket exhaust manifold (tubular, equal‑length): $300 – $600
  • Downpipe (3‑inch with flex section): $150 – $350
  • Cat‑back exhaust system: $300 – $700

7. Cooling System

The 510’s original radiator is too small for a turbo motor. An all‑aluminum cross‑flow radiator with electric fans is the standard upgrade.

  • Aftermarket aluminum radiator (dual‑core or triple‑core): $200 – $500
  • Electric fans (Puller style, wired to thermostatic switch): $100 – $300
  • Coolant hoses and overflow tank: $50 – $150

8. Intercooler and Piping

Even at 200 hp, an intercooler is strongly recommended to keep intake air temperatures in check and prevent detonation. Front‑mount kits for the 510 often require cutting the core support.

  • Front‑mount intercooler (core ~24x12x3): $200 – $500
  • Piping kit (2.5‑inch aluminum, couplers, clamps): $100 – $300
  • Blow‑off valve (recirculating or atmospheric): $50 – $200

9. Drivetrain and Suspension Upgrades

The 200+ hp will overwhelm the 510’s stock differential (R160) and flimsy suspension bushings. This is often overlooked in budget plans.

  • Limited‑slip differential (R200 or R180 LSD): $500 – $1,500
  • Heavy‑duty axles (300ZX or custom): $300 – $800
  • Suspension bushings (polyurethane set): $200 – $400
  • Upgraded springs/struts or coilovers: $600 – $2,000

10. Labor Costs

If you don’t have a well‑equipped shop and fabrication skills, paying a specialist is the safest route. Many shops that build classic Japanese cars charge a premium.

  • Professional swap labor (engine, transmission, wiring, basic fabrication): $1,500 – $4,000
  • Clutch and flywheel installation (if bundled): $200 – $500
  • Dyno tuning: $400 – $800

Beyond the Core Components: Hidden Costs

The items above cover the “big ticket” parts, but the 510–SR20 swap almost always reveals additional needs once the engine is out.

  • Clutch and flywheel: A new clutch kit (organic or puck‑style) and lightweight flywheel — $300 – $700
  • Radiator hoses and custom routing: $50 – $150
  • Oil cooler and thermostat: $150 – $400
  • Gauges (boost, oil pressure, water temp, wideband AFR): $200 – $600
  • Brake upgrade (front big brake kit or Z32 calipers): $400 – $1,200
  • Rewiring the 510’s chassis fuse box for the SR20 sensors: $100 – $300
  • Miscellaneous hardware, gaskets, and fluids: $200 – $400

DIY vs. Professional Installation

Performing the swap yourself can save $1,500–$3,000 in labor, but it requires a solid mechanical background, welding skills, and access to a lift. You’ll also need specialty tools: a transmission jack, engine hoist, torque wrenches, and a crimper for weatherpack connectors.

If you’re new to engine swaps, consider budgeting for at least 40–60 hours of labor (a professional shop can do it in 25–35). The hidden time cost of research, troubleshooting, and redoing mistakes can add weeks to the project. For many enthusiasts, paying a shop like Z Car Works or a local Datsun specialist is money well spent.

Achieving 200+ HP: Tuning and Supporting Mods

A stock SR20DET (around 200–205 hp from the factory in S13 form) will get you to your goal with just a comprehensive exhaust, bigger intercooler, and a boost increase to 10–12 psi. But to keep it reliable, invest in a proper tune.

  • ECU tuning: If you use an OEM ECU, an EPROM chip from Nistune allows real‑time tuning — $200 – $500 for the board plus tuning session.
  • Boost controller (manual or electronic): $100 – $300
  • Wideband oxygen sensor (for tuning): $150 – $300

With a good tune and the supporting fuel system, the SR20 can safely produce 250–280 hp on stock internals. Pushing beyond that requires forged pistons, rods, and a larger turbo — adding $2,000–$5,000 to the build.

Total Cost Estimates: Realistic Scenarios

Here are three real‑world budgets for a 200+ hp SR20DET–510 swap. Prices include engine, transmission, mounts, wiring, cooling, fuel, exhaust, intercooler, and labor if indicated.

  • Budget DIY build (used parts, home wiring, no LSD): $4,000 – $6,000
  • Mid‑range build (rebuilt engine, professional wiring, basic suspension): $7,000 – $10,000
  • Premium build (low‑mile JDM engine, stand‑alone ECU, coil‑overs, LSD, tuned): $12,000 – $16,000

These are estimates; actual costs depend on how much fabrication and problem‑solving your specific 510 requires. For example, some 510s need steering column or heater box modifications to clear the turbo manifold—that’s time (and therefore money) you didn’t plan for.

Conclusion: Is the SR20DET Swap Worth It?

For the Datsun 510 enthusiast who wants a reliable, modern powertrain and the ability to embarrass much newer cars on the track or back road, the SR20DET swap is one of the best upgrades you can do. The engine is plentiful, parts are cheap, and a well‑executed swap will hold its value—or even increase the car’s worth.

But be realistic: you’re looking at a minimum of $4,000–$5,000 for a scrapyard build with considerable DIY sweat, and a turn‑key, fully sorted car will run $10,000–$15,000 by the time you’re done. Plan your budget, stock up on patience, and join a community forum like Ratsun.net for real‑world advice. A 200‑hp SR20 510 is a joy to drive—but it won’t come cheap.