Alright... First off this thread is asking for a whole lot of opinion. Please share FACTS to support your opinions. I only say this because through the recent saturation of bmw information into my neural network became way overloaded and i'm not sure if i'm coming or going just yet lol.
The Car to build: 1986 325E Auto
The Donor(s):
1984 528e m20b27 eta 200 head automatic - suspect bad ecu and body damage not worth repair otherwise was recently on-road by another owner. have whole car
1990 325i m20b25 885 head automatic - we as a family rolled it 4 rotations, thankfully seat belted in but car mangled. drove it on the trailer. car scraped, kept engine, harness, ecu, trans, front and rear susp.
1994 325i M50tub25 ran hot, #3 wet (gasket or cracked head) 5spd. have whole car.
The Car to build:
1986 325E Auto I have never seen this car run. straight body. so-so interior. Previous owner description needed fuel pump. Have not even looked at this car, pushed it off the trailer, been sitting a while. This car is about to get raped in a very unnatural way. I'm simply not interested in a 325E run of the mill diving board bumper car.
right now i have opportunity to buy a core M54B30 complete minus oil pan & oil pump. which #2 has low/near zero comp (no broken valve springs, no visible cam damage, leak down puts loss air into #3 but oddly #3 doesn't leak into #2 (im still perplexed on this and decided not to diagnose this engine for my customer at the shop, rather m54 plentiful and simple R&R completed.)
So there you have my scrap yard. which we have 2 objectives with. #1 is build me something bmw to play with something e30! (miss the 90 late bumper car). #2 is get rid of the scrap yard.
the RULES:
NO limitations to the mod factor or rat/rod nature
Gotta be CHEAP or FREE.
Gotta get what I want out of the above scrap yard quick (clean up my yard)
Gotta be manual trans
Gotta be boosted.
Gotta be 5 lug
I know this is not going to end up really free. But we will ebay, fabricate (best of my ability), re-engineer, to pinch a dollar.
Lets start with Transmission, get that out of the way. The 1994 car has the getrag 5sp. Its got a lightened cast flywheel,clutch bolted to the M50 My understanding is that this should work without issue minus the fact i'm starting with an automatic car. The rear ratio i'm not sure but most likely need to use that rear end as well to match trans gearing. And I'm jumping the gun (suspension) here but I am seriously gunna place the e36 rear sub under the car and see what it would take. I do know that the z3 rear bolts in but i don't have one.
On to engine I wanna keep it real with the M20 I do. I'm tempted to gamble with the M54. It would take $100 to be mine. (i'm a tech at an indie shop sometimes have access to random cores at cost)
All of the above M20's i know have 200Kmi confirmed. I was gunna re-hone slam some std rings and carry on. Essentially I have two eta engines, one "i" engine.
Questions arise like:
Do I mate the "eta" bottom to the "i" top for the 2.7 stroker? ring it and boost that? Then some people argue that the piston-chamber mismatch is no good. detonation issues? the lower CR is probably ideal however for mild boost.
'
Do I source a 731 head for a better piston match (against the rules $) and port to the "i" accessories with the "eta" bottom.
Do we try to come up with (i have not yet) some other working internals configuration utilizing m50/m54 parts. in all cases I found requires $1200 custom pistons (rules$)
Keep the "i" engine complete and use a thick gasket to get the CR down a little?
I would really like to narrow down my best option for engine configuration.
I'm sure through this we are wondering about this BOOST requirement. I have worked on some boosted tuner cars but never had anything turbo. I know the power the m20b25 makes in an e30 and we are looking for more. I have two TD04 turbos from dodge neon srt-4's problem is they have integrated cast iron manifolds It may never work, but a lesson in cast welding might be in order. If that doesnt fruit then probably gunna get one of those infamous ebay turbos. this is undecided. twin TD04 would be fun build to fab up. Not to mention the later N54 in the *35i's sport twin TD04 turbos (ugh what a mechanics job those are).
Engine Management? Immediate plans are Speeduino. Probably the crudest minimalist barely worth of running an engine. then again.... we are replacing motronic 1.1/1.3. this means batch firing and fueling. but I'm 100% new to tuning. This is more about the lessons to be learned than the car to be built. I do expect a car to be build none the less. Speedduino will afford a ultra low cost means to a tunable ECU. MS3 would be the next in line. some basic electrical engineering skills are possessed here. Tuning is the technical area I intend to explore.
I am going to stop this rabbit hole right here, and ask you guys if you had to the above 4 cars powertrain and had to build out the 86 e30 E car, what would you do?
Later we will get to other things like getting the 5-lug accomplished, and feasibility of a full on e-36 susp into the e30 but please do not entertain these yet. lets scrap some cars and keep what we need.
Thanks for reading my ridiculous lengthy post which is only beginning. If this needs moved I'm happy to relocate to the proper place if needed.
I’d use the 90 325i 885 head and harness on the eta block with arp studs, je cut-ring headgasket. Then build a diy megasquirt 2 for it.
Last edited by BFresh; 10-02-2018 at 09:05 PM.
BFresh, thanx I appreciate your time and value the opinion. Would you happen to know the compression figures for that?
I have been considering the ARP studs. I'm glad you can help solidify that.
Would you able to substantiate the claim mating of e36 5spd to m20 compatible minus driveshaft etc. Thanks.
Last edited by tuxit09; 10-02-2018 at 09:27 PM.
Compression will be probably around 8.8-9, but everyone has a different opinion about that. A e36 getrag 5spd will bolt right up and work fine on your m20. Be for warned though they don’t handle much power at all compared to the e30 getrag 5spd’s.
You could also just run the complete m20b25 with arp’s/je cut ring headgasket to keep the torque down a little so the trans will last a little while.
A junkyard m50 is better than the best m20 in the world. Part out your crap, put an m50 in it with your getrag, run it on an MS1, and get an hx35 to put on it.
Well, I'm fresh out of good M50's but have 3 M20's that run. Additionally I will take seriously the mentioned Holset turbo, I have come across that more than once during research.
MS1 I'm not sure about the specifics but I am pretty sure it shares majority of the same technical limitations as the Speeduino project( ie. too few outputs for sequential fuel or ignition etc).
Specifically Speeduino project uses TunerStudio, Shadow Dash same as MS
Last edited by tuxit09; 10-03-2018 at 06:47 PM.
I ran an ms1 for almost 10 years starting with an m20 and then m50. Two years ago, I finally upgraded my existing board to an ms2, and now I have an ms3pro ultimate. An ms1 built on a V3.0 board is all you need to run an m20 or m50. You need to run it on msextra code to realize all the features available. For an M50 you can add 6 coil drivers to the bottom side of the heat sinc to run the stock coils in wasted spark. For an m20 add 3 coil drivers and use the coil pack from a Chrysler minivan in wasted spark. Much better than the factory distributor. Lots and lots of extra outputs and inputs to run other stuff like boost control, launch control, the stock idle valve, ect... Sequential fuel is of very little benefit for doing what you trying to do. I ran 2200cc injectors in batch fire and it was fine. If I can run mid 9’s with it you’ll do just fine.
ETA block plus 885 head is 8.3:1 compression. That’s not an internet guess, I measured it 10 years ago and posted all the info on e30tech but people still argue about it. Mine ran good up to about 15-17 psi on 91 gas and was octane limited after that. With a few gallons of race gas mixed in i ran it at as high as 23 psi on the street. Probably 350-400whp. Stock headgasket and class 12.9 cap screws for head bolts. Personally I’ve been through a turbo m20 and it’s a viable option but I would never do it again. M50’s are cheaper and stronger and make so much more power but I won’t belabor the point. If it’s what you can do go nuts.
Last edited by someguy2800; 10-03-2018 at 10:20 PM.
That
https://www.diyautotune.com/product/...-w-black-case/
plus that
https://www.diyautotune.com/product/...-39mod-kit-39/
An extra 2 of these for wasted spark
https://www.diyautotune.com/product/...river-mod-kit/
Will run a turbo m20. 10 years ago there were lots and lots of us who built turbo m20’s and most of us were running these. Nothing has changed to make them less effective.
I stand corrected compression would in fact be 8.42, the man knows his stuff 👍
https://www.bimmerforums.com/forum/s...#post_11205512
same here with the m20s. i think i blew 3 of them. kicked allot of ass with 25psi and meth.
Great little motors stock form they start to get fun after 20psi.
plus e30s are almost extinct from junkyards
there are completely stripped and honestly its luck if the head or block is still in it.
where do the m10 guys (is there any) find blocks?
m30s are almost the same. right now m54s and n52s are flooding the junkyards.
Last edited by Robocop; 10-05-2018 at 08:11 PM.
Yeah my buddy just paid more for a m20b27 at a junk yard then I did for a m50 lol.
^^^ Really? And here I just let one rust in my backyard, it's a lawn ornament now.
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