Turbocharging my BMW?

I have a 91' bmw 525i it makes "189 hp" I want to do a frankenstein turbo on it (take a volvo or any turbocharger from a junkyard car) and slap it on mine I already run 91+ octane. What i want to know is how much boost can I put on my engine without causing any damage? My engine specs are on this page http://www.bmwworld.com/engines/m50.htm (the one made in 1989) the compression ratio is 10.0:1 What preparations do i have to do too?

Turbocharging my BMW?antispam

If you want to turbocharge your beemer you will have to lower the compression either with a metal head gasket or new pistons. 10:1 is way too high for a turbo engine should be round 8:1-8.5:1 Then get an exhaust manifold made to mount the turbo to. Next you need to upgrade your fuel system bigger injectors, bigger fuel pump etc. Then you need to either have your computer remapped or better yet replace it with something like a microtech, haltech etc. Not to mention intercooler and piping, oil and water lines to the turbo. Best bet would be a garrett item off a R33 skyline. There is a bit more involved than just slappin a turbo on.

Turbocharging my BMW?avast

Buy a 2007 BMW 535i with a twin-turbo, 300 HP 6 cylinder and save yourself the money, agony and potential issues with turbo charging an old car. You're going to have to live with iDrive but you can still shift gears and drive a performance luxury sedan. The 335i is just as good for $10K less and no iDrive forced down your throat.
I wouldn't run more than 6psi of boost on a stock motor.
the best option would be to sell the car and just buy a faster BMW, but if you're really set on turbo charging your car, you are better off finding a turbo kit that is made for the vehicle. I know that Active Autowerks and a couple of other BMW specialists offer turbo and supercharger kits for a 1991 525i. You can add a turbo to BMW's stock engine without blowing it up (immediately) but without extensive modifications to the engine you will need to run relatively low boost (below 12psi). Even so, the kits that are sold for your car require a host of modifications including fuel pressure regulators, injectors, exhaust manifold, plumbing, additional oil lines, etc. Would also be nice to add an intercooler. It is definately possible to do what you want to do, but at the cost of shortened engine life, extensive trouble shooting and a lot of money. Would research available turbo kits made specific for your car and stay away from piecing something together from misc. parts.

I would still consider saving your money, enjoy the car for what it is and look for a faster car! Good luck.