E36 325i turboconversion
 

Hello BMW fans,

I have a '92 325i m50 and want to ad a turbo for some extra power. Now I read a bit about it on the net but but I want to keep it simple.
I already have a T3/T4 turbo, intercooler and exhaust manufold.
I want to keep the ECU as is and work with a vortech 10:1 fuel pressure regulator and maybe bigger injectors (now it's 166 cc/min).
My questions are:
Do I put the air mass sensor/meter between filter and turbo or between intercooler and inlet manufold?
Which size injectors can I use without getting complaints from the ECU?
Like mentioned I want to start basic and not change the motormanagement (ECU) that might be done later.

Best regards,

Jaap

T3/T4 dosen't mean a whole lot, what does the turbo map look like and where do you want it to "hit" in the power band? How much boost do you plan to run and what is your end game effective compression ratio? Do you plan on modifying the engine to handle more than 12:1? You WILL have to run 91 or better octane fuel. Go here http://www.turbobygarrett.com/ and under "Turbo Tech" start with turbo 101. You may be in for more than you're bargaining for, maybe not. But get the info from the guys who develop and make the stuff, and good luck.

I'm in the process of also puting a turbo on my '95 M50. First, you do not need a new pressure regulator or fuel pump for up to 1 bar boost. The stock ECU is your best choice, however you will need a custom tune to handle the increase of fuel to air mixture. Talk with Mike McCoy at TRM www.racersmarket.net concerning your project and he can send you a new chip for your DME 413 with your tuning requirements. The OBDI cars are easy to tune with the stock ECU. You need a 3 1/2" Porsche 803 mass air flow meter to handle the charge, doesn't matter if you put it before the turbo or after the intercooler as it read the density of the air. You will need to upgrade the injectors to 42 lb. injectors, TRM has these.

Good Luck

If your statement 12:1 is refering to compresson ratio, you are absolutely wrong. When forced induction is applied to (gas) internal combustion engines, you must lower the compression to accomodate the increase of air and fuel. He is right in that you must determine what your goals are, do you want low end torque or upper end power. This will determine how you set the turbo up in terms of exhaust turbine house size. Generally speaking a .63 A/R housing is best for low end torque and a .82 A/R is best for upper end torque.

Again, Good Luck

I'm sorry, how am I wrong about the END EFFECTIVE COMPRESSION RATIO. That would be your engine's normal ratio, plus whatever it is after you boost it. IE 8.5:1 normal compression + 7-8 pounds of boost, end effective ratio of around 12:1, that determines what kind of octane fuel you need to run to avoid detonation. To much boost, to much end effective ratio, wrong or not enough octane BOOM, new engine time. Not enough fuel, mix gets to lean, BOOM new engine time. DO THE MATH to determine you injector size and required fuel pressure and the intercooler goes AFTER the charger BEFORE the intake, otherwise you're cooling air into the turbo where it gets really damm hot and then dumped into the intake, no point for the intercooler then. Air charge get HOT under compression and picks up huge heat from the turbo itself, THEN it needs to be cooled to regain density for use by the induction system. Go to the garrett page read and learn. Or better yet go enroll in a tech school that actually teaches this stuff.