Engine Management
Engine management is the most important part of a turbo set up; period. If you don't have engine management your motor WILL BLOW. Now since you're adding air, you need to add fuel. There are 3 ways of doing this, using an FMU, using an AFC, or using real management. An FMU (fuel management unit) is a boost-dependent devide which increases fuel pressure per pound of boost. This is shitty because it overloads your stock injectors to flow more than they're supposed to. Plus there is NO way of tuning with a FMU. Your motor is just getting more fuel, not more fuel where it needs it. I feel if you're going to turbo that you NEED injectors. DSM 450's (blue tops) work quite nice, and can be had for cheap money. Now there are 2 types of injectors, saturated, and peak and hold. The difference is in the impedance (one is high, the other low). I'm not sure which ones you need because i always forget. However You'll more than likely need a resistor box to run them because they're a difference impedance from honda ones. Otherwise they should drop in with small modifications to the seals. Any other injectors made for a honda will work too as long as they're in the 450cc range. Basically any injector that is a top feed and fits will work, but you should research first. You could also get a set of RC engineering injectors if you want but they're like 100/injector. Now to controll the injectors you can use a safc or vafc (one is made for vtec engines the other isn't and both are made by apexi) which is a fuel controller. This is nice if you don't have someone who can tune an ecu for you. Basically you trick the ecu into adding more fuel. It's not the best way to run it, but it's better than an FMU in my opinion, and i believe Arnel ran a vafc for over 3 years without problems. I'm not going to get hardcore into the theory, but basically your ecu is sending an electrical pulse to the injectors which has different lengths. So if it sends a pulse to an injector that is more than twice the size of the stock injector, you're going to get way too much fuel. The vafc "hack" (see the step by step section to set up the hack) alters the MAP sensor voltage which in turn modifys the ecu's fuel and ignition tables. Essentially when you take out fuel it will advance your timing. To address this issue some people run an MSD BTM to retard the timing (per pound of boost), some people will change the timing at the distributor about 2 degrees, and some people like me don't give a shit and just drive it. The afc hack works sweet around 7 or 8 psi.
The last and best engine management solution is a piggyback/standalone. Now a standalone is something that totally replaces your ECU (like AEM EMS). The tuning capability is un-real, and so is the price, it's about 1K. A piggyback system is something like the greddy emanage series. I'm not entirely sure how it works but i've heard if you can find someone to tune it, it's not bad. However the best solution in my opinion is chipping a honda ECU. What you need to do is find a stock OBD1 ECU that can be chipped (and corresponds with your car, for example if you have a 99 GSR, then you'll want an ECU out of a 93-95 GSR, etc although there are exceptions to the rule). Next the ecu needs to be chipped. I'm not entirely sure what modifications this entails but there are plenty of places that will do this for you, or better yet you could always buy one chipped. What this does is allow you to burn your own program onto a chip and plug it into the ecu, effectively re-writing the honda program. A chipped ecu can usually be had for around 100 bucks and don't pay more than 140. Now to make it all work you need a program. I personally like CROME because it's easy to use and it's free. (check
www.tunewithcrome.com) However, there's also uberdata, turbo edit, and a few others. Once you get a program you'll need to essentially tune your car. I'm not getting into that cause that's a subject in itself. But it is possible to find people to do it for you. Then you'll need a chip burner, burn the chip, plug it in, and see how it turns out. Idealy you'll want to tune your car with a wideband O2 sensor so you know what your air to fuel ratio is so you don't blow your shit up (and use an EGT sensor if you're a true gangsta). Dyno tuning is great, but street tuning will suffice too.
Miscellaneous
You'll want to get a fuel pump. You don't have to but just think of it as cheap insurance. I got a brand new walbro 255LPH for 100 bones and it took all of 10 minutes to install. Also, the stock honda MAP sensor will only read up to 11 psi of boost. After that, it'll trigger a CEL and if you're tuning with CROME or similar, you won't be able to tune effectively past that point. A GM 3 bar map sensor will work and there's also motorola 2.5 bar map sesors i believe. Also if you're running the vafc hack and you're OBD2, expect a check engine light. Although the hack prevents the MAP from seeing boost, the MAP has a barometric pressure feature integrated into it and it WILL sense boost, giving you the inevitable check engine light. Best way to prevent this is to get a chipped ecu. Also if you run an OBD1 ECU you'll need a conversion harness they can be had for about 100 bones as well. Another thing people say is when you throw the turbo on to "prime" it with oil by cranking the car over. Personally i think it's kinda horse shit because most turbos have oil in them when they're shipped, plus most turbos don't spin at idle anyway. All you need to do is pour some oil in the inlet before you hook up the oil line; done. If you're running a new or reman turbo then you should break it in. 100 miles is usually a good idea, just to let everything wear in properly. Also hook your vaccuum lines up at the intake manfold. If you hook them up to a compressor nipple (aside from an internal wastegate) you will lose some boost pressure because of the pressure drop caused by the intercooler. Another suggestion is to run one step colder spark plugs. You don't have to, but if you're running a vafc i recommend it. With an ecu, just tune it good. Also YOU MUST RUN HIGH OCTANE. That should be a no brainer but if you run shitty gas it WILL CAUSE DETONATION. Low octane gas cannot withstand the effective compression of the boost and will leave you with parts on the road. It's also not a bad idea to change your clutch out. Most clutches can handle the extra power, the question is, how long. Especially if they have a lot of miles on them. Also make sure you run SYNTHETIC oil. Don't be a cheap bastard, turbos demand good oil so it doesn't coke up in the lines and whatnot. Lastly if you follow all this a RESEARCH then you should be good. I can't emphasize enough how important the SEARCH button is on a forum and how invaluable researching stuff is. Make sure you know what you're doing before you attempt to do this. Lastly, GOOD LUCK!!!
List of Good sites:
www.tunertoys.com - everything homemade turbo related
www.stealthmodeperformance.com - oil lines/restrictor
www.lsdmotorsports.com - clutches, flywheels, pipes
www.johnnyracecar.com - awesome intercoolers
www.bmcrace.com - flanges, adaptor plates
www.xenocron.com - ECU chipping/tuning solutions
and lastly
EBAY- but beware, if it's too good to be true, it usually is.