I found a cool write up on the ka-t setup
good info for you guys that lack the knowledge of the ka-t..


Turbocharging a KA24
Turbocharging a naturally aspirated motor is nothing short of a complete reinvention of the motor. Turbocharging the engine means replacing vast ammounts of the fuel sytem, exhaust system, and intake system. It takes time, money, effort, and ingenuity. People are often deceived by cheap turbo kits, not realizing that turbo setups are incompatible with stock fuel systems. When you do piece together a turbo kit, keep in mind your goals, and then go from there.
Companies like Greddy sell complete turbo kits for the KA24DE, with injectors, intercooler piping, downpiping, and even management. I feel that this is not the best option because of the price involved. For the same ammount of money (over $3,000) you can piece together a kit of much greater potential. However, a full turbo kit is the easiest option to acquire, and by far the easiest to install.

KA turbo setups
There are basically 2 fundamental turbo manifold designs to choose from: top and bottom mount. Top mount turbos are often the larger turbos that won't fit below, and for the KA24DE are typically T3 flange. The bottom mount manifolds are in the style of the JDM motors, and are typically T2 flange.
Choosing between a large T3 flange turbocharger and a smaller T2 flange setup is often a matter of goals. The best of the T2 turbos can support big power, but the larger T3 or T4 turbos simply produce more volume at higher boost levels. Some good T2 setups include bottom mount GT28R setups, which are relatively affordable and provide big power. A stock Nissan T25 is probably the most affordable option, if you are going for low levels of boost. On the T3 side of things, TD04 turbos are readily available in the US, coming from Diamond Star Motors. The TD04 is a quite small T3, and doesn't provide much more flow than the stock Nissan T25 that was used on the SR and CA motors. Larger T3 and T4 turbos are available at more expense, but the possibilities are endless. T3/T4 hybrids are a great midrange option, and come as large as .83 A/R. I personally use a T04E, which is quite large. Even larger T4 turbos come in sizes up to 1.04 A/R and beyond. Selecting a turbo is purely a matter of preference, goals, and money. If you aren'tplanning an engine rebuild, don't invest in a massive T4 turbo, but rather go with a more affordable bottom mount T2 setup.
Most turbo units are internally gated, but some use external wastegates to regulate turbo pressure. External wastegates are generally more common on larger turbos like the top mount T3's. External wastegates are louder, but more expensive.

Turbocharger support
Along with the turbo, manifold, and wastegate (if applicable), many other accesories are needed to complete a turbo setup. Turbochargers are incompatible with stock fuel systems. An intercooler, intercooler piping, blow off valve, downpiping, oil lines, injectors, fuel pump, and management are necessary to complete a turbo setup. A front mount intercooler is by far the best and easiest option for intercoolers. They are also inexpensive. Intercooler piping needs to be welded, but universal kits are available for just over $100. Blow off valves vary in design and performance, but mount on to the upper intercooler piping and slough turbo pressure when the throttle plate is closed. Downpiping is easy to fabricate, and any exhaust shop can do this inexpensively. Oil lines are pricey but necessary for turbo installation.
People often supplement their turbo setups with accessories such as turbo timers, but these are unnecessary. Replacing the small 240SX MAF with a larger MAF is a good idea for higher flowing intake, and is necessary for some management options.

Fuel systems and management
Fuel systems and management are by far the most variable and tricky part of a KA24 turbo build. Injectors are the first step. Although it is technically possible to run a turbocharger on the stock KA24E or KA24DE injectors, a minimum of 370cc/min is recommended for any turbo setup. In the KA world, this means SR20DET injectors for the KA24DET crowd. The SR20DET injectors are 370cc and are easy to find from people who upgrade. They can be acquired for around $100. For the KA24E, the smallest injectors that are readily available are the DSM 440cc injectors. People often upgrade to much larger RX-7 top feed injectors, which came in many sizes ranging from the popular 550cc type up to 760cc. Aftermarket fuel injetors for both fuel rails are available as well, with companies like Tomei, Sard, Denso, and MSD. Aftermarket injectors are quite expensive, but are obviously very large and easily available. I personally think that injectors from other cars is the best way to go for a first step. After you have the injectors, a larger fuel pump is needed. The Z32 300ZX fuel pump is a common mod, and can be purchased from salvage yards or on eBay. Walbro 190 and 255 lph fuel pumps are also commonly used. It is common to replace the restrictive 240SX fuel filter with the better flowing Z32 fuel filter as well.
Management is needed for the new air/fuel mixture that is present in turbocharged motors. Management options are diverse. The cheapest option is the fixed type FMU (fuel management unit) which mechanically provides a constant air/fuel mixture. These are the most affordable way to provide fuel to a turbocharged engine, but are not the best. Digital options are the next step up, which include SAFC-II, AFR, and E-Manage. These are not terribly expensive, and provide the best fuel management for the money. These units digitally manage fuel flow, and provide excellent variability for the money. The next option is a chipped ECU. Jim Wolf Technology is the most famous provider of this service, but these are quite expensive and not user-reprogrammable. The biggest option is, of couse, stand alone fuel management. Stand alone is a complete ECU replacement. Companies such as AEM sell their EMS units which provide exactly what the name promises, All Engine Management. Stand alone is quite expensive, but can support extremely high horsepower applications while providing the greatest level of tuning flexibility.

Piecing together a turbo build and it's components is all a matter of goals and finance. It's easy to get way out of hand with it, but I tell people that they can assemble a KA turbo for $2,000 if they play their cards right. Building a turbocharged motor is one way to reinvent the 240SX and turn it into what it perhaps should have been from the factory: a turbocharged, iron block 4 cylinder with limitless possibilities. Good luck to all who venture into the land of KA-T!