Exhaust Piping

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The Datsun 1200 used a 1-1/2 inch exhaust system. The cast iron exhaust manifold has a flat two-bolt flange. A donut-type asbestos seal was used to connects to the exhaust pipe, which extended past the rear axle. Finally a very, very quiet muffler with a short tail pipe was suspended by two rubber rings.

muffler with integrated pipe
Bottom (old) is the factory piece

A12GX Engine (twin carb) models used a quieter exhaust with a small resonator as well the regular muffler:

Notice it also used a cast header with dual outlets.

Sizing for Performance

A large diameter exhaust pipe is needed for maximum high-rpm horsepower. However, a small diameter pipe is needed for low-rpm horsepower. So you can see that a properly sized pipe -- not too big or too small -- is advantageous.

Single Exhaust

• Stock 68/69 horsepower A12: 1-1/2"
• lightly modded A-series engine: 1-3/4"
• 100 hp engine: 2"
• 150 hp engine: 2-1/4"
• 200 hp engine: 2-1/2"

Of course you can vary this. For example:

• The larger the engine relative to your car, you can get away with a larger pipe. Although the larger pipe cuts down on low-rpm horsepower you have a big engine so it's not so bad. This increases high-rpm (peak) horsepower
• For better street driveability, go a size smaller
• For drag racing where it is flat-out full throttle, a larger size may work fine

2.5 inch

Options

• Muffler system with resonator
• Chrome tailpipe extension (bell-shaped)

  

Coupe vs. Sedan

coupe muffler

• The bends are slightly different.
• The hanger near the end of the tailpipe (in the photo: where the price tag is) is a different place for sedan vs coupe

Part Numbers

Muffler measurements from my car (original muffler?):

• 11-5/8" Shell length
• 8-1/4" Shell oval width
• 3-3/4" Shell oval height
• 1.5" front inlet, centered
• 1.5" rear outlet, on far left of oval

A muffler about 2" longer may fit.

Nissan JDM Catalog

• 20010-H1000 TUBE ASS'Y-exhaust, front - ALL (exc. GX, Automatic)
• 20010-H1020 TUBE ASS'Y-exhaust, front - Automatic
• 20010-H2301 TUBE ASS'Y-exhaust, front - GX 4-speed
• 20010-H3400 TUBE ASS'Y-exhaust, front - GXA (GX Automatic)
• 20010-H7200 TUBE ASS'Y-exhaust, front - GX-5
• 20603-H2300 GASKET-exhaust tube - GX and GX-5
• 20602-27700 NUT-fixing, tube end (2) - ALL (except GX, GX-5)
• 20602-27700 NUT-fixing, tube end - GX-5
• 08915-13810 WASTHER-spring lock (3) - GX-5
• 20635-18000 STOPPER-muffler bound - ALL
• 20100-H1000 MUFFLER ASS'Y-with rear tube - Sedan
• 20100-H1400 MUFFLER ASS'Y-with rear tube - Van
• 20100-H2500 MUFFLER ASS'Y-with rear tube - Coupe
• 20630-18000 RING-rubber, muffler clamp (2)
• 20620-H1000 CLIP-tube, exhaust
• 06915-43810 WASHER-plain (2)
• 08915-13810 WASHER-lock
• 08110-85510 or 08110-86010 BOLT
• 08911-10810 NUT
• 20640-18000 STRAP-exhaust hanger
• 20641-18000 WASHER-plain (2)
• 08911-10810 NUT (2)
• 08915-13810 WASHER-lock (2)
• 08110-82210 BOLT (2)
• 20321-H2500 FINISHER-exhaust - GL, GX
• 20720-N2225 SEALER KIT-exhaust tube joint - ALL

USA Catalog

• 20010-H3100 ASSY-TUBE EXHAUST FRONT Sedan Manual Trans (formerly 20010-H1000) $34.92
• 20100-H7001 ASSY-MUFFLER WITH REAR TUBE Sedan Manual Trans (formerly 20100-H1000) $84.72
• 20321-H2000 FINISHER-EXHAUST (chrome extension)
• 20321-H2500 FINISHER-EXHAUST (chrome extension) $18.36

Aftermarket 1.5

• Dynomax 17700 ("Thrush turbo"),similar shape to stock. Oval 3.25 in. x 7.75 in. Oval 3.25 in. x 7.75 in.
• Merit 5582, 6669 or 3047

1-1/2 pipe clamps:

• Merit M112 or U112

Rubber Donut Hangers

• Merit 8166 ???

Aftermarket GX (is it the same as the S110 gasket?)

• Gasket: Merit 8696
• Pipe: (1981 Nissan 720), Merit 48316

Exhaust Tip - 1-1/2" diameter

• Merit 9821

Aftermarket 1.75

• Walker Super Turbo WLK-17771
• WALKER Pro-Fit Muffler, 1.75" offset/center, #17881
• [Dynomax 17771]
• Borla XR-1 BOR-40483 Stainless Steel, 1.75 in, 2.25 out