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DISCUSSION => Swaps, Turbos, Buildups => Topic started by: TheStorm on September 02, 2011, 04:24:56 AM

Title: M42 Turbo setup
Post by: TheStorm on September 02, 2011, 04:24:56 AM
Hello All,

I have been checking this club for a time, but just now I thought about registering here - so this is my first post.
I have one E30 M42 for ... hmm stupid things like drifting and racing :D and now I am after turbo build. So I am thinking of the following setup :

M42 standart pistons
M20 135mm rods
M47 crankshaft
little port and polish of the head (just to make it smooth
MS as standalone
The thicker 2.03mm gasket from BMW 11121721550

I think I can go with 1bar pressure.

So I need advise for two things for now - the turbo and the crank. I was reading and reading about the M47 cranks but I am still not exactly sure what things need to be tweaked so I can use the M47 crank. Some grinding of 0.6mm on the front and some other thing I saw. Can you please explain me in simple words - pictures better :D
About the turbo - because I need not so much power but response instead - I was thinking of veeery short turbo piping and also some turbo like from Subaru, Mitsubishi or Nissan - the stock ones. Or at least for the first phase of the project. Can you please say - I have this setup with this turbo and on xxxx rpm I have full boost until xxxx rpm.

The car currently is fully stripped, yesterday I removed the dash also. I will have some work on the body ... you know 20yrs cars can have "little" rust :p I want to build the car slowly but to have good product at the end. I will try to not rush things because my wish to drive :cool:
Title: M42 Turbo setup
Post by: Massimo on September 05, 2011, 10:07:36 PM
Anyways that is just some food for thought will save you lots of cash, the last person I heard of buying a M47 crank spent over $1000 just on the crank. From what I understand is that the key slot from the timing chain sprocket needs to be cut out and I believe one of the cranks is to long I think. Metric Mechanic dose a 2.1lt stroker of the M42 where they use a M47 crank they also tell you what they do to it you can read it here.

http://www.metricmechanic.com/pdfs/metric-mechanic-m42-and-m44-engine-booklet.pdf (http://www.metricmechanic.com/pdfs/metric-mechanic-m42-and-m44-engine-booklet.pdf)

Secondly don't make the ports smooth that is a big mis-understanding. As the fuel runs down the port it hits the port walls where it sticks, and when it is smooth it dosn't re-atomize, therefore reducing efficiency. When the ports are ruff the fuel re-atomizes which is what you want.

As for a turbo a stock wrx turbo should be good they make around 300hp and that is where you will probably be.
Title: M42 Turbo setup
Post by: visionracingdevelopments on September 08, 2011, 08:47:10 AM
I've got a Rotrex super charger set up for sale if you fancy going that route?