Budget M42 turbo build

[Schnitzer318is]

Just a heads up... not sure of your power goals, but if you plan on more than 180 torque, you will need a new clutch soon. I don't know where mine is at, guessing 210rwhp and not sure on the torque, but my clutch lasted about 3 months before starting to slip. Now it slips really badly with 10psi of boost in 3rd, 4rth, and 5th.

Will follow as I am a sucker for a boosted m42... good luck, have fun, and keep up the good work.

[e30guydownunder]

Looking good mate, dont fret on the updates. Mine have stopped completly :) Gotta keep the enjoyment levels up and sometimes that means taking a break ;)

[gearheadE30]

Sorry, I've gotten a bit lazy with the updates, heh. Megasquirt should be installed and in the car by tonight, assuming that everything tests correctly. I have all of the wiring diagrams drawn out, so I will likely be scanning those in and posting them at some point for future reference. There isn't a whole lot to take pics of, but here are some. The first two are the adapter board with most of the wiring installed for the coil drivers, spares, the DB37, and the LC1. There are a few circuits on there for the PWM, the coil drivers, the cam input, and the relay running power to the drivers. The last two are of the MS unit.

[gearheadE30]

I got the first part of the MS adapter done, so now I have pickup points for the entire factory harness without having to cut everything up. This box will also contain the cam sensor circuit, and will have plugs running out of the case for the LC1, the Megasquirt module, and a pickup point for testing cam, crank, injectors, and coils. Note that the coil drivers are still on the board; one has wires hooked to it for testing.

[gearheadE30]

Well, the issue that has stalled my progress recently was my inability to figure out why my tach and injector circuits were flaky. For any of you using a stim to test DO NOT USE 9V BATTERIES! They die unbelievably quickly and don't quite have the juice to make everything run right. I'm using a 12v power supply now, and as a word of warning, the stim voltage reg will get a bit warm, so you can't leave it on all the time.

[gearheadE30]

haha works for me; you aren't the first who has been interested.

Progress is coming along, but I don't really have any more pics. The adapter board is about half done and I have figured out how to wire the coil drivers, so those parts have been ordered.

I did some datalogging with the LC1, and it turns out that my engine runs an AFR of about 14.0 at a cruise and around 13.6 at WOT, so there should be a little power and perhaps quite a bit of economy to be gained just by going to megasquirt, assuming a good tune.

[ck_taft325is]

So, you're going to be my "go-to-guy" when it comes to doing this myself? Love that you made it all look stock. Never anything better than keeping the refined elegance of an e30 in tact when you do some "serious" mods such as turbo's and stand alone management. What's your boost goals? I'm considering staying mostly stock engine management and running only 6-7psi.

[gearheadE30]

LC1 is in and working after a few glitches. The module is under the center console, the access ports have been routed to the glovebox along with wiring for the inverter to power the laptop in the car. All of the wiring is into the factory harness, with the white and blue ground wires (LC1) soldered to one of the whites (pin 3 iirc) and the grey. The signal wire, is black, and is connected to the yellow output as a NB simulator for the time being. The brown output isn't used yet. Power is taken from switched power in the aux fuse box. The black calibration wire was extended and then run back into car to the center console. The LED and the switch are both under the ashtray.

Pics, as promised:


midway through the install

The glovebox

Nice and factory looking, just the way I like it. Minus the dirt.

[gearheadE30]

Little update here; I'll get some pics up later. Still not sure what the deal is with the tach signal, but I need to build another VR circuit for the cam sensor and finish the coil drivers. I'm actually going to be using the stock drivers, for what that's worth.

The LC1 showed up yesterday, so that is being installed now. The control module is in the center console, and it will all be wired into the factory harness just to make it look pretty and such. I'm really hoping that the narrowband mode will work with motronic for a little while, though, untill Megasquirt is done.

[gearheadE30]

haha same. It does give one a sense of progress, even if there isn't any...

Well, Megasquirt is now completed. I have a little bit more work to do to get the coil drivers working, which may be why I'm not getting a tach signal. The other issue there, though, could be that it is a VR signal, and Megasquirt stimulators apparently don't do a very good job of replicating that signal.

Also, I just picked up a Dell Inspiron 8100 for $100 for in-car tuning purposes, so I should be all set to go for getting it wired this weekend.

[Simon S]

Cool project.

I fuckin love pictures of accumulated parts. Looking forward to seeing how things go!

[gearheadE30]

Well, not much has happened recently, but megasquirt is assembled save for some of the in- and outputs. It works great and is going to be running MSextra 2.1.0 and will be tuned with megatune, as with most people. I'm going to try to run it with the OEM ecu controlling idle as well, just for convenience's sake, although the PWM valve shouldn't theoretically be too difficult to run with megasquirt. The coil drivers will be the factory grounding transistors wired into the Megasquirt controller, because I know they work and I already have 4 of them that I know work. Wiring might be interesting, though. I'm still between running wasted spark with the packs run in pairs or trying to rig up full sequential ignition, which, as far as I can tell, may not be much more difficult.

Also, I'm shooting for getting megasquirt operational in the car this weekend, but I'm not sure how realistic that is yet.

[Asbradley21]

Can't wait to see this. I know it's going to be done the right way.

[ck_taft325is]

Subscribed.

I want to do this same thing to my Alpine 318is.

[gearheadE30]

yeah, plus there are already a ton of swap cars running around. Yes, I know I could have done an M50/M52 swap for about the same money, but I've grown attached to the M42 haha.

Anyways, I did make some progress today. Got the compressor and turbine housings pulled of the turbo, and the seals are BAD. It hasn't been used in awhile and there was still oil in the compressor housings. Of course, I'm going to put new bearings in too, even though they still have a bit of life left in them. Pics of the CHRA and the compressor housing:




No contact marks!


Also finished building JimStim v1.4, although my board says it is actually a v1.5. For those who don't know, the JimStim is an expanded stimulator for testing the Megasquirt controller, and is vital for modern BMW engines because it supports up to 6 virtual ignition coils where the normal one only supports 1. It's really a pretty simple build and didn't take too long. More pics:




And here is a little teaser pic of sorts of about half of the parts I have accumulated, if that haha: