Hey I would like to know where you could get some 8 to 1 or 8.5 to 1 compression pistons for the 318ti. The Ti stock has 10 to 1 compression. I am thinking about a rebuild with possibly a Turbo. If I run the 8:1 compression I can run a little more boost and get more power out of the car.

What parts do you need to replace in order to do the cylinder swap. Ive been thinking about doing it for some time now but dont want to have any surprises on the weekend and have all the shops closed.

I am stilll checking into everything, but basicly a set of gaskets (I am trying to track down a Copper Head gasket, to take the pressure from a Turbo), you will need to get the Pistons and Rings, you should be able to use the rods that you have. While you are in there you might as well replace the bearings. In general check everything else out. Basicly you are rebuilding the engine.

Keep me posted on what you find out. This is what a "Analog Kid" posted on Bimmerforums.com:

Depends on what Octane you plan on using.

8:1 provides a large window for tuning, but since you lack (displacement), "lag" may come into play, but again, the ball bearing turbo will make it very short. I would reveiw and verify the compressor maps for that turbo....


Look into:
-Forged Connecting rods, as they will take a beating @20psi, if you havent already.

-An IC designed to be efficent at 20psi (2.36 pressure ratio...is alot..)

-@ 20 psi, if you really do plan to run that much...youll need a strong headgasket and some head studs.

-You will defintely need to feed it fuel to feed that beast.

-Hell, kiss your clutch, tranny and rear drive goodbye now