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The Datsun 510, often called the "poor man's BMW" for its rear-wheel-drive layout and independent rear suspension, has earned a loyal following among vintage Japanese car enthusiasts. Built from 1968 to 1973, this compact sedan and coupe offered a lightweight body and nimble chassis that made it an ideal platform for modification. While the stock L-series four-cylinder engine provided decent economy, its 96 horsepower left much to be desired for anyone seeking real performance. In this article, we’ll walk through performance testing a Datsun 510 before and after several popular modifications, comparing the power gains and real-world driving improvements. We’ll also cover the testing methodology, costs, and what to expect from each upgrade path.
Why the Datsun 510 Is a Tuner Favorite
The Datsun 510’s appeal lies in its simplicity. Weighing around 2,200 pounds (997 kg) in stock form, it’s light enough that even modest horsepower increases yield impressive acceleration. The car’s double-wishbone front suspension and independent rear suspension gave it handling that was advanced for its era. These factors, combined with a huge aftermarket following, make the 510 a perfect candidate for both bolt-on modifications and serious engine swaps. Enthusiasts have swapped in everything from turbocharged L-series engines to SR20DET and even V6 or V8 powerplants. But even without an engine swap, you can extract meaningful gains with careful tuning.
Establishing a Baseline
Before we began testing with modifications, we needed to record the car’s stock performance. We used a chassis dynamometer for power measurements, a GPS-based accelerometer for 0-60 and quarter-mile times, and conducted all runs on a flat, straight section of closed airport tarmac. Ambient temperature was 70°F, and the engine was warm. The test car was a 1971 Datsun 510 four-door sedan with the original 1.6L L16 engine, a four-speed manual transmission, and 3.90:1 rear axle gearing. Fuel was 93-octane pump gas. Here are the baseline numbers:
- Engine power output: 96 hp at the wheels (crank estimate: 108 hp)
- 0-60 mph: 10.0 seconds
- Quarter mile: 16.8 seconds @ 84 mph
- Peak torque: 96 lb-ft @ 3,600 rpm
These numbers align well with period road tests. The car felt peppy around town but struggled to merge onto highways. The exhaust note was quiet, and throttle response was lazy. We knew the car had potential—now we needed to unlock it.
Modification Round 1: Bolt-Ons & Tuning
We started with the easiest upgrades: a cold air intake and a performance exhaust system. These modifications require no internal engine work and can be done in an afternoon with basic tools.
Cold Air Intake
We installed an aftermarket short-ram intake with a washable cone filter and a heat shield. The stock air box was restrictive, especially at higher rpm. The new intake reduced airflow restriction and lowered intake air temperatures compared to the factory setup. We kept the factory carburetion for now, but we rejetted the primary and secondary jets slightly richer to match the increased airflow.
Performance Exhaust System
We replaced the stock cast-iron manifold with a 4-into-1 header, a 2.25-inch mandrel-bent intermediate pipe, a high-flow catalytic converter (for street legality), and a turbo-style muffler. The system reduced backpressure significantly. The car sounded more aggressive, but we were after performance, not just noise. After the exhaust and intake install, we re-dynoed the car.
Results after cold air intake and exhaust:
- Wheel horsepower: 108 hp (crank: ~122 hp)
- 0-60 mph: 8.8 seconds
- Quarter mile: 16.0 seconds @ 88 mph
We gained 12 wheel horsepower and 0.8 seconds in the quarter mile. The engine now revved more freely past 5,500 rpm. Throttle response improved noticeably.
Modification Round 2: ECU Tuning (Distributor Advance & Rejetting)
The Datsun 510’s stock distributor uses mechanical and vacuum advance. By recurving the distributor and adjusting the timing curve, we could optimize spark timing for the new airflow. We also switched from an electronic ignition conversion kit to a high-energy unit. On the carburetor side, we dialed in the air/fuel mixture using an air-fuel ratio gauge. We set the idle mixture to target 13.5:1 and the main circuit to 12.8:1 under full throttle. Total ignition advance was increased from 10° to 14° initial, with a total advance of 34° by 3,000 rpm.
Results after distributor recurve and carburetor tuning:
- Wheel horsepower: 115 hp (crank: ~130 hp)
- 0-60 mph: 8.2 seconds
- Quarter mile: 15.5 seconds @ 90 mph
The mid-range torque felt stronger, and the engine pulled harder from 3,000 to 6,000 rpm. Quarter-mile time improved another half-second.
Modification Round 3: Engine Swap – SR20DE
For the most dramatic gain, we swapped the original L16 for a naturally aspirated SR20DE engine from a 1995 Nissan 200SX. This engine makes about 140 hp at the crank in stock form and weighs only about 30 pounds more than the L16. We used an aftermarket engine mount kit, a matching five-speed manual transmission (with a shorter first gear), and a custom driveshaft. We retained the stock rear axle but upgraded to limited-slip differential. The swap required wiring modifications, but we used a plug-and-play engine harness. Cooling was handled by a new aluminum radiator with electric fans. We kept the exhaust from the previous upgrade, adding a 2.5-inch downpipe.
Results after SR20DE swap:
- Wheel horsepower: 130 hp (crank: ~155 hp)
- 0-60 mph: 6.9 seconds
- Quarter mile: 14.2 seconds @ 98 mph
The car felt completely transformed. Throttle response was instant, the engine revved to 7,000 rpm willingly, and the extra torque—about 140 lb-ft—made the car feel punchy at any speed. The 0-60 time dropped more than three seconds from stock. The quarter-mile trap speed increased by 14 mph.
Modification Round 4: Lightweight Flywheel & Clutch
We added an 11-pound lightweight flywheel and a stage 2 clutch to reduce rotating inertia. This is a common upgrade on SR20 swaps. The car now revved faster and engine braking was more pronounced. We tested again:
Results after lightweight flywheel and clutch:
- Wheel horsepower: 132 hp (marginal gain)
- 0-60 mph: 6.7 seconds
- Quarter mile: 14.0 seconds @ 99 mph
The flywheel didn’t increase peak power much, but it made the car feel quicker. The quarter-mile time improved another two-tenths.
Modification Round 5: Suspension & Tires
Power is useless without grip. We upgraded the stock suspension with Tokico Illumina adjustable shocks, stiffer springs (250 lb/in front, 200 lb/in rear), and polyurethane bushings. Tires were upgraded from 185/70R13 to 205/50R15 on 15x7 wheels. We also added a rear sway bar. While suspension doesn’t increase horsepower, it dramatically affects acceleration by improving traction out of corners and reducing wheel spin. We repeated the 0-60 and quarter-mile tests:
Results after suspension and tire upgrades:
- 0-60 mph: 6.5 seconds
- Quarter mile: 13.8 seconds @ 100 mph
The car now shot off the line with minimal wheel spin. Braking distance also improved. While the dyno number remained around 132 wheel horsepower, the car felt noticeably faster in real-world conditions.
Final Comparison Table
| Modification Stage | Wheel HP | 0-60 mph | ¼ Mile |
|---|---|---|---|
| Stock (L16) | 96 hp | 10.0 sec | 16.8 sec @ 84 mph |
| Cold air intake + exhaust | 108 hp | 8.8 sec | 16.0 sec @ 88 mph |
| + distributor & carb tuning | 115 hp | 8.2 sec | 15.5 sec @ 90 mph |
| SR20DE swap | 130 hp | 6.9 sec | 14.2 sec @ 98 mph |
| + light flywheel & clutch | 132 hp | 6.7 sec | 14.0 sec @ 99 mph |
| + suspension & tires | 132 hp | 6.5 sec | 13.8 sec @ 100 mph |
What We Learned: Best Bang for the Buck
If you’re on a budget, start with the cold air intake and exhaust. That cost us about $600 and netted 12 wheel horsepower and a 0.8-second improvement in the quarter mile. Adding distributor recurve and carb tuning (another $200 in parts) gave another 7 hp and 0.5 seconds. Those bolt-on modifications are reversible and don’t require major mechanical work.
The SR20DE swap is the most transformative upgrade, but it’s also the most expensive. Expect to spend $1,500–$2,500 for the engine, transmission, mounts, and wiring, plus another $1,000 for labor if you don’t do it yourself. However, the performance gain is massive: 34 additional wheel horsepower and a 0-60 time that rivals a modern sports car. The lightweight flywheel and clutch upgrade ($400) is optional but recommended for throttle response. Suspension and tires ($1,200) are essential once you exceed stock power levels.
Common Pitfalls to Avoid
Many Datsun 510 owners rush into engine swaps without addressing the brakes and cooling system. Our car’s stock drum brakes were marginal with the extra power, so we upgraded to front disc brakes from a Datsun 610. Also, the SR20DE’s cooling demands are higher than the L16’s; a stock radiator will overheat on a hot day. We installed a modern aluminum radiator. Finally, if you choose forced induction (turbocharging), you’ll need a standalone ECU and forged internals—the stock L16 cannot handle significant boost without major work.
External Resources
For detailed swap guides and community support, visit Datsun510.com, one of the longest-running forums for 510 enthusiasts. For parts, FutoFab offers high-quality suspension components and engine swap parts. Technical information on L-series engine builds can be found at ZCar.com, which covers similar Nissan inline-four engines. For dyno testing best practices, refer to Innovate Motorsports for wideband O2 sensor tuning guides.
Conclusion
Performance testing the Datsun 510 before and after modifications reveals just how versatile this classic platform is. A stock L16 is reliable but slow; with a few hundred dollars in bolt-ons and tuning, you can gain 20-30% more power. With an engine swap, you can achieve over 130 wheel horsepower in a car that weighs just over 2,200 pounds—giving it a power-to-weight ratio better than many modern hot hatches. The 0-60 time dropped from 10.0 seconds to 6.5 seconds, and the quarter-mile trap speed jumped from 84 to 100 mph. These are real, measurable gains that translate to a much more enjoyable driving experience. Whether you’re a weekend cruiser or a track-day fanatic, the Datsun 510 delivers when you put the right modifications under the hood.