M42 build rotrex + gt3076

[Oriol]

Hello everyone, I am introducing myself from Barcelona, I have an e30 318is in the process of a track car and I wanted to share the project in this forum. First of all apologize for my English by google translate ... I wanted to start with the first modifications made to the car, it is a complete build I do not know if this will be the best section of the forum to post ...


At the beginning I just wanted a Rotrex supercharger to gain about 100hp with standard internals, but little by little I bought the ecu link, the connecting rods and forged pistons ... in the end, as the parts arrived, my goal was higher. Until a week ago I only had the idea of the Rotrex supercharger, but I was afraid that it would be a somewhat empty power curve at low revs.
I felt encouraged and bought a gt3076 to attach to the rotrex. In my mind the idea is a series assembly, a pulley so that the rotrex at 4500 is at its limit, then disconnect it with an electromagnetic clutch and that the turbo continues until 7000. I don't know if all this will be possible, but it is what I have proposed to do.


This is the day I bought the car from the one who is now my boss








The car was apparently in good condition, it had oem lsd 168mm, recaro seats and dbilas intake. But my boss already warned me that I had some badly repaired accident from previous owners. Don't pay too much attention to it. After a holidays on the nurburgring circuit with huge kerbs and too short suspension travel came the tragedy. the body was cracked really in very bad condition ...




this photo is after jumping a huge kerb, which just damaged the body

[zwill23]

Pics aren't working! Sounds like a cool build though

[Oriol]

The entire chassis at the front was cracked.
I had to repair it to continue enjoying this car.

[Oriol]

buy some struts reinforcements plates from intrax suspension










When I already had the chassis repaired, I decided to reinforce the subframe and make many modifications to move the engine 8 cm back for a great balance.

[Oriol]

New custom engine mounts arms



I have also rotated the front subframe 180 degrees already from e36, to give more caster to the wheel since the wishbone support is not in the center of the two holes of the subframe. With this and the oem silentblocks of the m3 e36 286cv, my car already had 9 degrees of positive caster according to the alignment machine. It is true that I had to completely modify the atachments of the steering box and it also offers the advantage of having the oilpan behind the subframe free of crashes.

I also had to make new e36 stabilizer brackets.
I do not have many photos of this process since I did not plan to publish any of this, when I can take photos and share them, I think it is a good mod.


Here you can see the difference in wheel caster with the standard configuration and the engine position


Now that we have the chassis in good condition we will start with the upgrades of the little 1.8

Engine specs:
crankshaft m42
cylinder block stock m42 84mm
forged pistons CPS 9:1 rc
forged rods ebay edition
arp cylinderhead and bottom studs
cometic headgasket
m44 cylinnderhead with stock cams
m44 timming case + 10mm oil pump (2mm more than m42)
rod and cranckshaft king bearings std size
700cc inyectors from asnu
340l/h petrol pump from asnu
link g4x extreme ecu
rotrex c38/61 kit
gt3076 ebay edition turbo

[Oriol]

Ok, it's time to disassemble the original motor and start measuring tolerances with the new bearings and install the crankshaft.




The weight comparison of stock vs upgraded piston an rod.

[Oriol]

I have read a lot about this since there is no certainty and after consulting several books my ring end gap setup: top: 0.55mm 2nd: 0.60mm 3rd: 0.30mm





Crankshaft bearing clearance

[Oriol]

Rod bearing clearance



The connecting rods and pistons have a good alignment of weights, there is only 1 gr of difference between them.




I used AMS engine assembly lube it is a very thick grease and it looks very good



Crankshaft pistons and rods instaled!

[Oriol]

The engine block is waiting to fall in love with the cylinderhead =)





only changed the valve springs retainers from a audi rs3/rs6

m44stock:



rs3 8v / rs6 4.0 fsi:

[Oriol]

The reason why i choosed the m44 cylinderhead is the valvetrain is 70% less friction than m42, from timing chain is better and today have spare parts in bmw (for m42 is ended) and the oil pump is 2mm larger than m42.




new timing chain new guides new oil pump and new chain case.





The engine is almost finished in the absence of the clutch flywheel and the mocal oil remote filter.
Ecu, dash and wiring harness:

[Victell]

I am very excited for this build. Subscribed!

[Oriol]

I'm really like more the analog speedometer, but at this point I needed something versatile that would give me a lot of information without having 100,000 gauges and something with laptimer programmable alarms and much more, I fell into the temptation.



With this I have also greatly simplified the wiring, removing the tacho temperature sensor, alternator charge signal, oil pressure switch ... I will use a pressure sensor, engine oil temperature, rotrex oil, gearbox oil and differential all to the ecu and from ecu to dashboard via can.
The dash will also solve some future problems with the differential speed signal, which we will teach you later.




and my chaos wiring diagram..

[Oriol]

the intake manifold is made without any calculation, it was something I did to learn aluminum welding, I plan to make one by taking a couple of volume calculations and more appropriate to my application.







When I built that manifold I still did not have this beloved book that I am sure you already know but it is 100% recommended:





In a few hours I have updated the status of my project in this thread, now I hope to be able to update weekly and advance the work, thanks to all!!

[downforce22]

nice, that is a cool build and a great book to read. What did you do with the Individual throttle bodies (dbilas)?

[Oriol]

nice, that is a cool build and a great book to read. What did you do with the Individual throttle bodies (dbilas)?

I sold them a year ago...