Do's and Do Nots
Here are a couple of things to look out for if you do turbocharge your KA24 240SX.
* Do Not get greedy and turn up the boost past 10 psi unless you're absolutely sure of your tuning.
* Do look into colder and more capable spark plugs.
* Do Not skimp on the fuel management; the more shortcuts you take, the more likely your engine will blow up.
* Do change the stock exhaust or your turbo will be fighting excessive backpressure.
* Do upgrade to a 255-lph fuel pump and larger side-feed injectors.
* Do think about a larger radiator. The turbo adds a lot of heat to the engine and pushes the stock cooling system to its limits.
* Do Not buy the super cheap tubular exhaust manifolds found online. These tend to break and crack easily.
* Do plan on putting in a stronger clutch and limited-slip differential because all this torque will smoke the clutch or the one tire that is spinning.
* Do periodically check for intake and exhaust leaks from loose bolts and fittings. Also look for excess blow-by oil.
* Do Not forget to get an oil cooler and oil-catch tank if you want to prolong the life of your hardware.
Nissan 240SX Turbo
Engine Code: KA24DE
Type: Inline four, iron block, aluminum head, turbocharged and intercooled
External Modifications:
Holset HX35W diesel turbo, custom welded log manifold, Tial 38mm wastegate, 3-in. downpipe and exhaust, Magnaflow titanium muffler, modified Dodge Ram front-mount intercooler, Bosch (OEM VW) blow-off valve (recirculated system)
Engine Management Modifications:
Walbro 255-lph fuel pump, modified AEM Honda fuel rail, 440 cc/min RC injectors (top feed), Vortec 4:1 FMU, D-tec piggyback fuel controller
Drivetrain
Layout: Longitudinal front engine, rear-wheel drive
External
Wheels: 17x8-in. 5Zigen FN01R-C
Tires: 215/45-17 (F) and 235/45-17 (R) Falken RT-215
Penny pinching with a diesel turboNic Cheek's primary goal was to keep his KA24 turbo setup cheap, but not to cut corners where it really mattered. Emphasis was placed on three main areas: the fuel system, the engine management system and the turbo manifold. As we've said, scouring your local junkyard for a turbo is usually much cheaper than buying the usual T3/T04. But why not the turbo from a diesel truck? Sure, it's big, but when the Holset HX35W from an early 90s 5.9-liter Cummins Turbo Diesel can be had for $100, who cares?
These turbos tend to be readily available and have a T-3 flange. As an added bonus, Nic was able to grab an intercooler core while he was under the hood, too.
To make the custom log manifold, the outline of the stock exhaust flange was traced onto a slab of half-inch steel and cut out. The runners are pieces of stainless steel Weld-Els and straight tube welded together to fit in the space available. Another piece of half-inch steel was used to make the flange for the turbine housing. To properly manage exhaust gases, pipes branch off to a Tial external wastegate. Hot air is then channeled through a 3-inch downpipe to a Titanium Magnaflow muffler that Nic bought used.
On the charge side, it's pre-bent 2-inch elbows and straight pipe from the turbo to intercooler, and from intercooler to throttle body. The Dodge intercooler would never fit unmodified, it's nearly 18 inches tall. Cut horizontally into 3 pieces, two sections are used, one behind the other. The hand-made end tanks are plate aluminum; $30 from a metal scrap yard bought a big sheet.
By Henry Z. Dekuyper
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