Opinions: Twin turbo e30 m20 motor
 

wanting opinions on twin k03's on an m20 motor. car is an 89 325is.

i got two k03's, two sidemounts and whatever chargepiping comes from an 200X audi s4(even the diverter valves). my uncle upgraded his turbos to k04's and also his chargepipes so i got all those for free. free is good :)

since i got all those for free, i wanted to throw them into my 89 325is I6 motor. i know its a hassle to go with two turbos, especially the k03's since they're tiny as ---- but im working with what i got. i think i read you could flip the manifolds for the m20 so that you could make a topmount setup but not sure.

let me know what you guys think. im still looking for fuel and engine management. i dont really wanna go MS so looking for other options. not new to the turbo scene. had a two turbo hondas but this is gonna be my first turbo bmw so i guess its a whole new ballgame.

Megasquirt sequencer would do a good job on these engines, since you have them for free, you should try them, they are not bad at all and should be a little on the big side for your application but still fun to drive.
You will have to fabricate the inlet 3 bolts flanges, I searched and could not find any stainless ones, but nothing that a press drill can't fix

yea i was also wondering what i was gonna do for the flanges but i'll just have to custom make them. doesnt look like too much work.

i never thought twin k03's would be oversize for the motor considering the size of them, but is it basically splitting the engine in half per turbo? so like 1.75L per turbo? i think that the k03's are too small for a 1.8L still but free is whats driving this project so w/e.

also regarding twins, if both turbos are set at a 5psi internal wastegate, would that mean i would be recieving 10psi of boost? probably a noob question

i have seen a nice 325is running x2 Mitsi Tdo4h's so the K03's will be fine...

sounds tits guys. i spent a few good hours taking apart the twins and just cleaning them up and inspecting them. they seem pretty solid.

still thinking of ways to actually set them up but i know theres a lot of space in there and shouldnt be too hard.

If anyone has any pics they come across of a twin turbo 325 with the stock m20 motor, please post a link. Thanks

the 2.5 liter M20 in half will be more like 1.25 L. Still it should be nice.
The pressure will not add up, but you can cheat the wastegates to increase the boost.
Sound like a nice project.

I have seen this done with KO3's and TDo4's. If you flip the manifold you will have to do a ton of port matching to make it work. Not if, but when you go with megasquirt, get the M20 adapter board that they sell on diyautotune.com

Now go forth and do this.

The 325is that we had here were 2.7l 's

Incorrect, the 325i and the 325is had the 2.5l M20B25, the 325, 325e, and the 325es had a lower compression, more economical, 2.7l M20B27 motor. the 2.7l is no good for FI because the head on it flows horribly and it only has single coil valve springs which makes the rev limit ~5500. you can do a 327i swap tho if you have the money

read and weep

INFO ON 325iS and 333i - E30 Club SA