What size turbo?

[cjcoll3]

I am very interested in putting a turbo on my 225 slant six, but after doing some research I am still not sure as to the proper size I should be looking for. I am trying to get the parts together right now and have found an almost new T3/T4 turbo for $85. I was just curious whether or not this would be a good option for me, and if not what I should be looking for. I am not interested in racing this car, I just want to get a little more out of it as a daily driver.

 

[pishta]

That is just the flange size. You need to tell us the AR and the turbo diameter, like a .63 AR T56. That tells us the capacity of the turbo. You want to err on the small size, just like a carb. a Chrysler 2.2 turbo is a bit small but works but will run out of steam at about 4500 rpm. Larger turbos will not spool quickly giving you a "turbo lag". I researched and found that a turbo off a 3.0 Toyota Supra (CT26) was sized about right for the airflow that a 225 puts out. A liter is about 60 cubic inches, so a 225 is like a 3.7 but the head flows poorly making it seem smaller to the turbo. Too small a turbo will superheat the charge at high turbine RPM's reducing effectiveness unless you intercool. Too large a turbo will be lazy and wont produce the boost you need. Smaller AR numbers spool faster than larger AR numbers. That is the cross sectional size of the hot side where the gasses turn the turbine. with the low velocity of the 225, you need to look at smaller AR numbers to keep the turbo spool rpm's up. are you going to blow through or draw through?