DC Sports 4-2-1 Race Header
2,000 to 3,500 range: -2.0 to 5.0
3,500 to 5,500 range: 8.0 to 9.0
header, instructions, brackets, sticker, gaskets, mounting hardware
10-, 12-, 14-, 17-, and 19mm sockets, 12-, 14-, 17-, and 22mm open-end wrenches, 7/8-, 15/16-inch open end wrenches, ratchet, extension, crescent wrench, WD-40
The DC Sports 4-2-1 one-piece race header enables exhaust pulses to increase scavenging for additional horsepower in mid-range to top-end engine performance. Lighter than the factory cast-iron manifold, the DC header is manufactured using T409 stainless-steel alloy, robotic TIG welding, and is finished in a corrosion-resistant ceramic coating.
Because the DC Sports long-tube-style header is a cat-delete unit, it's labeled for off-road use only. Removing the factory header from a 15-year-old vehicle can become painstaking, as many of the nuts and bolts are rusted and difficult to remove. Be sure to use the proper tools and plenty of lubricant when removing each bolt.
The new header delivered impressive hp and torque across the board, with a gain of 7.0 hp and 9.6 lb-ft of torque at peak performance. The dyno also recorded impressive mid-range gains: 8 hp and 9 lb-ft of torque at 4,200 rpm.
'91 240SX Exhaust Camshaft
2,000 to 3,500 range: 0.0 to 3.0
3,500 to 5,500 range: -6.0 to -4.0
ratchet, extension, 10-, 12- , 14- and 17mm sockets, 10- , 12-, 14- and 17mm open-end wrenches, screwdriver, torque wrench, safety wire (used to secure chain tensioner), crescent wrench
Cheap, easy to find, and an alternative solution to purchasing aftermarket cams for the KA24DE, swapping Nissan S13 KA24DE cams into S14 KA24DE engines has been a popular upgrade for the past few years. Swapping a factory S13 KA24DE exhaust camshaft in place of the intake camshaft of an S14 KA24DE is rumored to be the best bang-for-the-buck power improvement for these engines-we tracked down our cam for $50.
S13 240SX KA24DEs run an intake cam with a duration of 240 degrees and an exhaust cam with a duration of 248 degrees. S14 KA24DE camshafts are rated at 232 degrees of duration for both intake and exhaust. Since duration is how many degrees of crankshaft rotation the valves stay open, the larger S13 exhaust camshaft-identified with an orange stripe from the factory-allows more clean air to enter combustion for more power.
Camshaft installation should be handled by an experienced mechanic to eliminate the chance of valvetrain damage. Depending on the mileage and condition of your engine, we recommend inspecting and properly re-adjusting the camshaft shims and buckets upon reinstallation, or replacing them with upgraded equipment if they're past their prime.
Nissan enthusiasts claiming to have tested the 248/232 cam combination report that it sacrifices a bit of top-end power, but delivers significant gains in the low- to midrange. Our testing revealed the opposite-the new cam didn't increase low/mid output, but did open up the KA's power band at high rpm, particularly above 5,500 rpm, where the stock combination fell off sharply.