3.1 L turbo

[fat325]

hey all.
just wondering if anyone has done a ie 3.1l m20 turbo?
i've herd that the 3.1L stroker can get 210-220. and a turbo 2.8L getting 350-400 but i havent herd of that combo. anyone seen this? would be interesting to see the power figures!
thanks, ash

[Dyno4mance]

I would not think the increased capacity would yield much more power on a FI setup....
with the additional stoke comes a less desirable rod ratio and higher piston speeds.this coupled with a head that does not flow would not be worth the addition coin...
However, having said this, the torque in the lower areas of the rev range would be a lot better and of course spool the turbo quicker....
My 2c

[Justin B]

I had plans deep in the back of my head to put a turbo on my M20 that I am building with a S52 crank and +2mm pistons. It ends up at 3.124 or something L total. Since then I've decided on just a completely NA build. I'd like to hear of one that's got a turbo though, that could be pretty wild. Mine is is also going into a 2002 anyway so it'll be just as fast probably :)

[SpecM]

I don't think you'd get all that much more power out of a FI 3.1 than a properly set-up 2.7 turbo

[fat325]

I would not think the increased capacity would yield much more power on a FI setup....
with the additional stoke comes a less desirable rod ratio and higher piston speeds.this coupled with a head that does not flow would not be worth the addition coin...
However, having said this, the torque in the lower areas of the rev range would be a lot better and of course spool the turbo quicker....
My 2c

thanks for the reply's
i would of thought the increase capasity would of made a fair bit of difference. could you go into detail about this undesirable rod ratio please? when you say the head dosn't flow, do you mean after porting and polishing as well? are they just a shit head?
thanks, ash

[Dyno4mance]

Sorry, my mistake I just did the calculation...138mm rods / 89.6mm crank =1.54 rod ratio I thought it would be lower than that...the engine would be able to safely rev to 7800rpm without piston speeds being too high (although billet rockers would have to be utilized...Having said that the head design is a bit long in the tooth as well as being a 12 valve design but turbocharging is a good way of masking those faults...
I suppose the incresed capacity may lend itself to running a slightly bigger turbo than a useable 2.7 liter motor resulting in more area under the curve without killing reasonable spool time.
Sorry for my initial negativity....Good luck with your project if you decide to proceed..

....

[Erick]

For all that work, just swap in a turbo M30. :p

[Dyno4mance]

For all that work, just swap in a turbo M30. :p

And make the nose plow like a Zamboni with the additional 80lb stuffed in the nose.....
Looking at the pic in your your sig I would of thought you understood car balance
Dont get me wrong the M20 is no featherwieght either but every bit helps.

[Erick]

Who honestly tracks their e30 hard enough to say that they need the perfect weight balance?

I've seen many M30 powered e30s doing just fine on the track too.

I have a turbo setup. It's heavy. My car is far from properly balanced. It's surely farther off from what BMW originally designed it. The car still handles great though. Perhaps I could swap around some spring rates, but my driver skill can improve the overall driving better than a 100% proper setup will.

[SpecM]

And make the nose plow like a Zamboni with the additional 80lb stuffed in the nose.....

I bet you won't notice.

[Money$hit]

cammed ls1

/thread

[SpecM]

cammed ls1

/thread

weighs less than an m20

ls1 ftw

[Erick]

Who wants to donate an LS1? :D