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m20 turbo
Posted: Tue Dec 28, 2010 6:48 pm
by mattyb
hello all and merry christmas.
been messing about with a set of gsxr throttle bodies for my m20 and doing alot of research and realised that its just not worth it. small power gains mainly.
so iv been researching turbos found alot of info on other threads on here but dont want to fill someone elses thread with my Qs.
so here goes
im lookin for about 300rwhp.
first of all what clutch will i need
iv read early high comp engines need an mls head gasket but where can i get one from and is there differnt thicknesses available if so which on would i need.
how do i tell if my engine is a high comp or low. its an 84 car but was converted at sytners to c2 2.5 in 86 so could be low comp.
i will be using an ebay top mount turbo manifold. as there cheap and i ill add a strengthener to it. and an external waste gate pipe if the turbo i need doesnt have an internal one.
i will be using an intercooler too but is bigger better or can you go too big,
which brings me on to what turbo i will need. i understand there is a few different ones that would be suitable for 300 horse power at the fly but will they be ok for 300 at the wheels
i will be using megasquirt ms1 ecu but what do i do with the air flow meter i read that i need a map sensor but will that get rid of the air flow meter or do i need maf too.
you guys must be sick of answering these qestions but your help will be appreciated, thanks
Re: m20 turbo
Posted: Wed Dec 29, 2010 7:37 am
by AlpineAde
I think I've mentioned UUC clutches before, but a Sachs heavy duty kit would cover your needs I reckon.
Re: m20 turbo
Posted: Wed Dec 29, 2010 12:43 pm
by mattyb
iv had a look on the net for both and cant seem to find either, dont supose u may know where i could get one from. cheers
Re: m20 turbo
Posted: Thu Dec 30, 2010 1:23 am
by 327ire
hey matt, you wont need the AFM with the MS1. There is a vacuum pipe that comes out of the ecu thats needs to be connected to any vacuum port in the intake mani. I just put a "T" piece onto the vacuum pipe on the back of the intake that feeds the fuel regulator.
As far as I know the early high comp engines have an "L" shaped idle control valve on the throttle body and the later low comp have a "T' shape.
heres a site with some mls gaskets...
http://store.vacmotorsports.com/vac---m ... -p977.aspx
heres a link to my intercooler. its not the biggest but it fit into the space without any cutting or hammering.
http://www.e30owners.com/forums/showthr ... 971&page=6
Re: m20 turbo
Posted: Thu Dec 30, 2010 8:49 am
by GeoffBob
Re: m20 turbo
Posted: Thu Dec 30, 2010 6:40 pm
by ross2009
to find out if ya got a low comp or high comp engine look down the side of the block on the intake side near the sump and there will be a stamped code on a machined flat it will either say 25 6e or 25 6k
engine code. 25 6 k1 is KAT prep 8.8:1 Cr , 25 6E1 is 9.75:1 higher CR.
Re: m20 turbo
Posted: Fri Dec 31, 2010 7:33 am
by AlpineAde
mattyb wrote:iv had a look on the net for both and cant seem to find either, dont supose u may know where i could get one from. cheers
Go here for UUC, matey:
http://www.nexternal.com/uuc/articles/main.htm
Search "E30" in their search box and check their kits. I love mine. Awesome gear.
Re: m20 turbo
Posted: Fri Dec 31, 2010 9:45 am
by mattyb
performance organic looks good to me gona get a quote for delivery now and get her ordered
Re: m20 turbo
Posted: Fri Dec 31, 2010 9:59 am
by mattyb
@327ire looks like a nice intercooler dude where did you get it from. also what dump valve you using iv been looking at forge motorsport one around 100 quid. atmospheric one that is.
Re: m20 turbo
Posted: Fri Dec 31, 2010 1:29 pm
by mattyb
theres a guy on e30tech that is selling a hx35 turbo with a 14 cm housing, im tempted.
Re: m20 turbo
Posted: Fri Dec 31, 2010 1:50 pm
by 327ire
I got a nice bosch dump valve from a saab turbo, 10 quid in a scrappy

. It can recirculate but i just vent to atmos. They take a 1" inlet.
My intercooler is an ebay job. I cant remember the dimensions tho. Something like 100£. I have it on 2.5" piping.
Re: m20 turbo
Posted: Fri Dec 31, 2010 2:25 pm
by mattyb
10 quid sound bettr than an ton. im gona use an ebay intercooler too.
Re: m20 turbo
Posted: Fri Dec 31, 2010 6:13 pm
by bss325i
mattyb wrote:hello all and merry christmas.
been messing about with a set of gsxr throttle bodies for my m20 and doing alot of research and realised that its just not worth it. small power gains mainly.
so iv been researching turbos found alot of info on other threads on here but dont want to fill someone elses thread with my Qs.
so here goes
im lookin for about 300rwhp.
first of all what clutch will i need
iv read early high comp engines need an mls head gasket but where can i get one from and is there differnt thicknesses available if so which on would i need.
how do i tell if my engine is a high comp or low. its an 84 car but was converted at sytners to c2 2.5 in 86 so could be low comp.
i will be using an ebay top mount turbo manifold. as there cheap and i ill add a strengthener to it. and an external waste gate pipe if the turbo i need doesnt have an internal one.
i will be using an intercooler too but is bigger better or can you go too big,
which brings me on to what turbo i will need. i understand there is a few different ones that would be suitable for 300 horse power at the fly but will they be ok for 300 at the wheels
i will be using megasquirt ms1 ecu but what do i do with the air flow meter i read that i need a map sensor but will that get rid of the air flow meter or do i need maf too.
you guys must be sick of answering these qestions but your help will be appreciated, thanks
First up it would be a shame to bastardise a very rare car (Alpina C2 2.5) with a turbo.
Secondly, your engine will be an eta block, 323i crank and rods, custom pistons with a comp ratio of around 10:1 (not ideal for high boost) and a 731 (320i/323i) head.
Buy a sept '88 onwards 325i with 8.8:1 comp ratio and turbo that.