Talk about a can of worms! Start with the basics:

• Exhaust: Get one. Enough said. The 3 inch CM downpipe is money well spent if you are going to keep the Nissan wastegate.
• Intake: Shut up and do it.
• POV: Plug it - the threads are 1 inch NPT. A plug can be had from any hardware store for under $1. Or you can waste $100 on an adjustable hks/greddy valve or you can shim the spring in the stock valve to make it hold as much as 15psi.
• Boost controller: Get one. Bleeders are bad. Spring loaded check valve style are good. Electronic doohickeys aren't worth the money for 99% of turbo cars. The Gillis boost controller is nice and cheap and comes with the proper size vacum lines even!

You can get around 250-275 horsepower depending. Unfortunately Nissan designs their engines with very little extra fuel capacity. By now you're out of fuel and your turbo is being run hard and making more heat than power. Nothing you can do at this stage(except for nitrous) will make any significant amount of extra power until you have upgraded everything(turbo, IC, fuel).

You need money next. More fuel capacity, more turbo capacity, and an intercooler. Which to do first? Whichever you want! The turbo would probably give more power alone than an intercooler. More fuel requires bigger injectors and something to run those bigger injectors.

• Fuel: Only two choices - JWT computer with larger injectors and Ford air flow meter. This will get you as much power capacity as you need. As a side benefit, you'll get the better timing and fuel curves of the JWT computer, giving an immediate boost of power with no no other changes. Expect 10-20 horsepower from the computer, a nice extra little kick in the pants. Computer: $600 Ford AFM: $200 Injectors: $600 from jwt, $300 from discount parts place. JWT AFM and injector info here.

  Your only other choice is a programmable engine management system. Ranging from cheap at under $1k to expesive at $5k or more for a fully optioned MOTEC system, you can get whatever you want. Installation and tuning are beyond the scope of this web site, and if you need info now then this is not the option for you.

  Once you outgrow the 420cc/min injectors(they will do over 400hp at the wheels) you can spend $100 a pop on bigger drop-in injectors or you can make your own fuel rails and use domestic o-ring injectors that are readily available in sizes up to 1600cc/min. Just ream out the injector holes and make the o-ring rails. Fuel rail stock is readily available from any fuel injection shop(kinsler, electromotive, AZ speed & marine, etc).

  • Fuel pump: A z32 turbo pump drops right into the tank very easily.
  • Regulator: If you use anything more serious than a z32 turbo fuel pump then a higher capacity fuel pressure regulator might be a wise move. Being able to tweak the fuel curve with an adjustable regulator is also required for the JWT 450 computers as they are programmed for a higher base fuel pressure. Do not ever consider a rising-rate regulator in lieu of any other modifications - they can be made to work decently, but they are a band-aid fix and are not worth the time/effort/trouble in the long run.

• Intercooler: Spearco kit(Best you can buy) is around $1200. HKS kit is nice, but not as good as the Spearco and costs the same. If you can find either one used buy it without thinking twice. Only way to beat the Spearco is to make your own plumbing. Don't bother with any OE intercooler except for that of a twin turbo supra. A starion or whatever core is not worth the trouble. Supra intercoolers can be had for $100-200 and are readily available on ebay or the mkiv.com mailing list. To clarify, only the mkiv supra(93 and up) intercoolers are any good, the mk3 units are complete garbage.

  Is any intercooler better than no intercooler? NO! An undersized intercooler can easily create enough pressure drop such that the additional exhaust backpressure will more than negate any gains from the slightly cooler air.

  The best way to go is to buy a good intercooler and make your own plumbing. 2.5 inch steel mandrel bends are $20 each from Summit. Just cut them up and weld away.

• Turbo: Another can of worms. You get what you pay for, if you go cheap you get cheap. If someone tries to sell you a 't3/t4 that makes 25psi' then run away fast. There are literally thousands of combinations of parts that can make a t3/t4 turbo - from one too small for a 2 liter honda to one that is too big for an 8 liter viper. Call a competent turbo vendor or buy a book on turbochargers and spec your own. A good turbo will run you $600-800 or so. Add $500 or so for ball bearings.

  t3/t4 simply means a turbo with a t3 turbine and a t4 compressor. There is nothing magical about this. There are 4 t3 turbines and 4 t3 turbine housings. There are dozens of t4 compressors and housings. Do the math and note that "t3/t4" includes hundreds of combinations. Add in tricks like putting a t4 turbine in a t3 housing, clipped turbines, etc, etc. and you have thousands of possible combinations.

  Turbo of choice for your vg engine will be a mid-sized t4. But the t3 and t4 bolt patterns are different, so how do you mount a t4 on your vg engine without the cost and effort of making your own manifolds? Simply have a t3 turbine housing bored out to fit the t4 turbine of your choice. Any competent turbo vendor can do this, run away if they say that this can't be done. This will almost require an external wastegate because of the size of the turbine - simply get/make a blank t3 outlet flange and use the internal wastegate hole for your external wastegate. Easy!

  The Nissan turbine housing's wastegate bolt pattern is different from the standard Garrett pattern, so if you use the Nissan turbine housing then you have to use the Nissan wastegate or make your own. If you use a Garrett turbine housing then you cannot use the Nissan wastegate.

  To upgrade to a t3 frame turbo from the t2 frame used on 88-89 models you will need the t3 oil line, t3 wastegate, t3 water lines, t3 inlet pipe, and the t3 turbo-throttle pipe. Then just bolt it in.

  With some creative cutting and welding on the driver's side engine mount bracket you can get a straight-line shot into the compressor and ditch the very restrictive stock inlet elbow.

The engine is plenty strong. A stock engine in good condition will easily support well over 400 horsepower with proper tuning(ie. don't let it knock!). A set of quality pistons will enable your otherwise stock engine to safely support 500+ horsepower with proper tuning.

If you're going to build an engine, do it right. Start with a vg33 to get the extra 10% displacement over a vg30 and you'll have 10% more power for free! Good pistons to lower the 9:1 vg33 compression ratio and good cams to replace the low-speed cam grind used in trucks and you've got a pretty good engine. Rebello, Sunbelt, and Malvern racing all build wonderfull Nissan engines, expect to pay around $5k for a basic high-quality reliable streetable engine.

Note that turbocharged engines have vastly different camshaft requirements compared to non-turbo engine due to the high exhaust backpressure and much higher pressures at the intake ports. JWT makes some very nice(and expensive!) turbo cams, as do Web, Isky, etc. Skip the lopey cams intended for a non-turbo on your car and make sure you get some turbo cams.