custom turbo kit?

ok, today i got the idea of biulding a cutom turbo kit if the compression on my engine is low enough. i dont plan to boost past 3 psi and am only doing this as a side project, since i figure it shouldnt cost me too much. please tell me if anything im writing is wrong.

a turbo is connected to the exhaust and intake manifolds. when isntalling a turbo, you need new manifolds because the old ones dont have an opening to connect to the turbo. i figure i can get old manifolds
from a junkyard, cut a hole in them, and weld on a piece of piping. all that matters is getting the right size piping and welding it together. i know someone who is a welder by trade and he can do this for me. the oil feed line shouldnt be any problem. i also figure that boosting at such small amounts wont require an intercooler. the only parts i dont understand are the blow off valve and wastegate. are they necesary? and will they take mdoficiation to put on? also, wat is the part that keeps the boost at a desired amount so i can boost at 3 psi even when the rpm's go up? shoudl thsi idea work? any input is much appreciated. thanx

A wastegate is what manages the boost. If you want to run 4 pounds of boost, theres a 4 lb spring in there, and once 4 psi is reached, the wastegate opens and the air bypasses into the exhaust or open atmosphere. A turbo kit can work without a bov, but without one, its extremely hard on the turbo and will reduce turbo life. Without one, when you let your foot off the gas, since the pressurized air cant be released to the atmosphere, its going to redirect back and into your turbo and stop the compressor from spinning. With 3 psi, an intercooler isnt neccessary, but for only 3 psi, I wouldnt even bother putting a turbo kit on the car. I would at least run 7 or so. I dont even think you can even by a 3 pound spring for a wastegate. Your also going to need some sort of engine management to adjust fuel, timing, etc.

What kind of car do you have? IIRC you have a 240 right? Just do a Revhard setup. YOu can find them very cheap on ebay. Very reliable when prepped right.

BOV vents air that backs up in the intake pipe between the turbo and the TB when the TB closes. Turbo is still making boost/flowing air, but when the TB closes, it has no where to go. Trys to turn the compressor wheel in the opposite direction. The BOV gets rid of this air so you don't damage the turbo.

The wastegate bypasses exhaust gas around the turbine housing by creating a leak in the exhasut manifold. It is a valve that opens when it reaches its set pressure. You run a small pressure line to the actuator. It reaches a certian pressure and pushes that valve open. When it opens, exhaust goes through the valve instead of going through the turbine housing. It keeps the impellers at a certian speed. Boost pressure is determined by what spring you put in the wastegate or what you set the Boost controller at(if you have one. Not necessary unless you want to boost past spring pressure).

IDK if there are any springs for that low of boost. I've seen 4.35psi springs before. You shoudl also at least run a small FMU. Even at low boost, it is possible to lean out running stock fuel system. And adding a little fuel is better than adding no fuel. You should also look into upgrading the fuel pump and changing out basic matinence stuff such as fuel filter, oil, PCV all that stuff. Good luck.

well this is for my sentra, and its not even the SER, its the luxury edition. my friend has a talon hes scrapping and said hed give me the turbo, so i started thinking if this was possible. i dont care about running 5 lbs of boost, i just dont know what this engine can handle. is there any way to determine how much boost an engine can handle? i havnt looked around once, but i doubt anyone has done this before. i only said 3 lbs to be safe.

do a compression test.

if you only do 3 psi you would be wasting your money. Most cars are built well enough to handle around 10psi w/ the right fuel management system. I know that is the case for d16y8 Civics anyway.

well this is a sentra luxury edition. the engine was designed for fuel economy, so i have no idea what it can take.

Hes right. Id say with 3 psi, you might pick up 30-40 hp. :disappoin You wont even be in the turbo's effeciency range yet. I cant justify spending a couple grand for a 40 hp gain. It would be cheaper to just get on the bottle.

i completley agree. the only reason i was planning on doing this was because it would be cheap. a free turbo from an eagel talon from my friend, and probably around $100 for the manifolds from a junkyard. piping shouldnt cost much, and the welding would be free. all i would need to buy would be oil feed lines for the turbo, and a wastegate. but i didnt consider fuel management, so im going to have to some more research to see if i actually need to upgrade it.