How to Choose the Right Performance Exhaust for Your Datsun
Start by matching the exhaust to your exact Datsun model and power level. A 240Z six-cylinder needs different sizing than a 510 four-cylinder, and the wrong diameter costs power or creates drone.
Clarify your engine and power target first
Write down your displacement, current horsepower, and any plans for turbos or cams. Most stock Datsun L-series engines run fine on 2.25-inch systems. Once you pass 160 hp, step up to 2.5 inches. A 280ZX with a mild rebuild stays happy at 2.5 inches; push it past 200 hp and 3-inch piping starts to make sense.
Pick diameter by horsepower range
| Horsepower | Recommended diameter | Typical Datsun example |
|---|---|---|
| Up to 140 | 2.0-2.25 in | Stock 510 or early 240Z |
| 140-180 | 2.5 in | 240Z with headers and carbs |
| 180-220 | 2.5-3.0 in | 280ZX turbo or built L28 |
| Over 220 | 3.0 in | 3.0L stroker with ITBs |
Choose material that fits your climate
- Mild steel works if you garage the car and drive it often.
- 409 stainless resists rust in wet regions and costs less than 304.
- 304 stainless lasts longest but adds weight and price.
A 240Z in the Pacific Northwest benefits from 409 stainless. The same car in Arizona can run mild steel without issues for years.
Balance sound level with daily use
Chambered mufflers like a Flowmaster 40-series keep the note mellow on a street-driven 510. Straight-through glasspacks get loud fast and drone on the highway. Test-fit a resonator if you plan long trips. Many owners add a cutout valve so they can quiet the system for neighborhood driving.
Confirm fitment and local rules
- Measure your transmission crossmember clearance and rear axle location.
- Check that the new system clears the fuel tank and spare tire well.
- Look up your state’s sound and emissions limits before ordering.
- Compare bolt patterns on the header collector or stock manifold.
Generic Z-car kits often need trimming on a 510 wagon. Order mandrel-bent sections and have a shop tack-weld everything in place first so you can adjust before final welding.
