2.7 m20 turbo?

[e30leigh]

hi there guys.

just after some info if anyone has run a turbo on the side of there 2.7 m20?

im asking as i may have come into the chance to grab one. and ive got my sights set on boost. original plans were 2.5 or 2.3. depending on what i could find. now that i may have the 2.7 close to in my hands i was woundering if anyone has done this. and what they did and what its like.

i know the factory redline is very low. making them a low rev, high torque motor.
what i mainly want to know is if they are happy reving to the likes of 7k. i dont know too much about the 2.7 motor as they are very rare in NZ. i also know the heads, cams and a few other things are different. and also compression.

any info on these motors would be much appreciated.

thanks, leigh

[The Humjet]

hi there guys.

just after some info if anyone has run a turbo on the side of there 2.7 m20?

im asking as i may have come into the chance to grab one. and ive got my sights set on boost. original plans were 2.5 or 2.3. depending on what i could find. now that i may have the 2.7 close to in my hands i was woundering if anyone has done this. and what they did and what its like.

i know the factory redline is very low. making them a low rev, high torque motor.
what i mainly want to know is if they are happy reving to the likes of 7k. i dont know too much about the 2.7 motor as they are very rare in NZ. i also know the heads, cams and a few other things are different. and also compression.

any info on these motors would be much appreciated.

thanks, leigh

The stock cr on an m20b27 is rather high. But if you use that bottom end and run b25 heads and everything else related to b25 you will end up with a pretty stout turbo motor than can properly rev to its red line.
But if you find a b25 then just go with that. This swap is one of things that if don't have a complete b25 then useing a b27 bottom end is another option. If you do then just leave it as a b25 it'll end up making more power anyway.

[e30leigh]

oh thats interesting.

i asked as i am having great troubles finding a b25. but a b27 has come available. but i think ill pass on it and keep looking for a b25 instead.

thanks.

[The Humjet]

Your better off. You should be able to yank one out of an e34 525i its the same shit as what's in the e30. That's what I did.

[e30leigh]

they are just as hard to find down here. most e34's have m30 motors. seems to be alot of m30b35s around at the moment. but i cant find a decent m20. its frustrating.

[Hey_You]

m30 swap! Seems to be the only logical answer

[Cyrix2k]

m20b27s run just fine under boost. I ran one for a while and it was a beast plus a few others have with success as well. Swap the b25 head on and you'll drop the CR significantly, but even bone stock works fine. - just be sure to replace the head bolts with metric blues at the minimum. The bottom end can take revs fine but the top end can't without replacing the valve springs. Up to about 5500 rpms is safe from the factory, but I wouldn't go beyond that without doing head work.