First MS/Standalone Project - S38 E30

[S38addict]

Hello everyone,

My name is Paulo, I'm from Portugal and a proud owner of an E30 with an S38B38 swap.
This will be my first standalone instalation and I think of it like a learning experience, which will require all the help I can get.

Some information about the S38:
OEM ECU: Motronic 3.3 - 88 pin
COP with igniters in the OEM ECU (not sure)
60-2 CKP
Single Trigger CMP (not sure)
Ressonance Flap in Intake Manifold that works with air pressure(changes effective runner lenght with 2 rpm/tps changeover points)
Stepper ICV (not sure)
Engine is stock

Objectives:
MAF delete
Learn as much as possible about EFI and its instalation
Tune it myself
Prepare for further mods down the road (turbo mayhem)

First set of questions:
1 - AFAIK this engine sports sequential spark and ignition from factory, should I try to keep that up with MS3 or would that be to hard for a novice user?
2 - Can I control the Ressonance Flap with some sort of PWM or on/off trigger? Maybe with a boost solenoid?
3 - Should I use the stock wiring as far as possible or ditch and do it all myself?

Thanks,
Paulo

PS. I'm buying a pre assembled unit cause I am not nearly smart enough to build my own

[Matt Cramer]

Welcome to the forum!

First set of questions:
1 - AFAIK this engine sports sequential spark and ignition from factory, should I try to keep that up with MS3 or would that be to hard for a novice user?

As you already have to make the distributorless ignition work, sequential injection won't be any harder. An MS3 with MS3X and QuadSparks is probably the easiest route here. In some respects, MS3 is a bit more user friendly than MS2.

2 - Can I control the Ressonance Flap with some sort of PWM or on/off trigger? Maybe with a boost solenoid?

Every intake flap type system I've seen has been a simple on/off. Never seen one that needed to be PWM'ed.

3 - Should I use the stock wiring as far as possible or ditch and do it all myself?

If it's in good shape, I'd use as much of the stock wiring as I could.

[S38addict]

Thanks Matt, I finished reading your book today, and thus felt confident enough to create this topic. Good job!

I am not too familiar with QuadSparks, but I undestand these are sets of 4 external coil drivers that plug between the ECU and the Coils. Am I correct? How can I be sure they will work with my BMW coils?

Other than the ECU, WBand, loom, coil drivers (quadsparks) and GM IAT, what else will I need to get going?

Here is the bad boy after some love


By pmoutinhoneves at 2012-05-30


By pmoutinhoneves at 2012-05-30

[prof315]

I am not too familiar with QuadSparks, but I undestand these are sets of 4 external coil drivers that plug between the ECU and the Coils. Am I correct? How can I be sure they will work with my BMW coils?

The QuadSpark is 4 mounted, heat sinked and prewired BIP373 transistors in a case. The BIPs work well with BMW COPs, been there done that.

[S38addict]

Thanks a lot.

Just brainstorming here, but what would be the best way to use the MS3 and still maintain most of the OEM intact so if I decide to go back to motronic, to use the MS on another project?

Try and divise a connection between the MS harness and the 88 pin motronic plug? Would this be very hard/ impossible?

[Matt Cramer]

I'd gut a stock ECU and solder pigtail harnesses to the 88 pin plug.

[S38addict]

Would there be any disadvantage to this solution? Would it involve a lot more work and potential issues?

For example the OEM IAT would be disregarded and the GM unit would need to be wired seperately, just as the spark igniters...

Do you have the link for a similar pigtail project on a motronic?


This is the Cam Sensor and the TPS. Will the MS3 control these without issue?


By pmoutinhoneves at 2012-05-31


Thanks,
Paulo

[Matt Cramer]

The OBD1 cam sensor and TPS are no problem for the MS to read. The OBD2 cars with the Siemens ECU used a screwball cam sensor that it's best to swap for the OBD1 version.

We normally stick an IAT sensor in the MAF wiring when using the stock harness. On cars wired for EFI, this is often the easier option.

[Rick Finsta]

Matt, is there a reason he can't use Easytherm and calibrate for the stock IAT?

[Matt Cramer]

Matt, is there a reason he can't use Easytherm and calibrate for the stock IAT?

Yeah, MS3 doesn't use EasyTherm. It's done through TunerStudio.

I can't recall where the IAT is located on these cars - on the earlier ones with Motronic 1.2, it's built into the air flow meter and not easy to separate from it, so early S38 owners usually end up running a GM IAT.

[S38addict]

Thanks for the replies.

I've checked your website and found something really interesting (as usual btw)...The DIYBOB, but as far as I can tell, there isn't one for the 88 pin motronic loom that the later S38B38 has. Is this in development? If not, why is that?

It would be great to have such a unit to help with the instalation...

[Matt Cramer]

The connector's proven very difficult to find unless we want to pay six figures to buy several thousand of them.

[justnsk]

Building an adaptor to the stock harness is the easiest way. Also it gives you option to make things in pnp style to switch to stock ecu in any time. All stock sensors should work. You only need to place some bip373 transistors for the coils. And to make the "start circuit" on the adaptor to switch on main relay.

The links below should help:
http://m-power.ru/text/remont/s38b38_terminal.htm
http://www.megasquirt.325ix.com/MS_to_M ... 3.3.1.html
viewtopic.php?f=131&t=43421&start=20#p307663

[Rick Finsta]

That makes sense.

I'd love the ability to tweak my sensors without reflashing; my CLT currently reads high by about 10-12*F... one of these days I'll swap up to MS3 (right before I go BOOSTED!)

/hijack

[S38addict]

Thanks justnsk, your explanation and links really helped.

I really need a crash course on board electronics, relays and electrical stuff in general. Can you suggest a book, something online or whatever?
I've seen a book on Amazon on Automotive wiring, but I'm not sure how useful it really is on my project...

edit* - this is it : http://www.amazon.co.uk/Automotive-Elec ... ef=lh_ni_t


Now even I think this is possible, thanks

Paulo

[justnsk]

I cant suggest a book, because I've never read any on this topic

Building an adapter is not a rocket science at all

And you can always ask some experienced guys on the forums.

BTW, ready-to-work adapter will look like something like these:
http://msextra.com/forums/viewtopic.php ... 9&p=313551
but with 6 transistors mounted with insulator.

[S38addict]

Hi there,

Sorry to bring this up again but I needed to be sure of one thing before commiting...

Are all 88 pin motronic connectors similar...I mean is a BMW M50 ECU plug the same as the one on a S38B38? Broken M50 connectors are somewhat easier to find

Best Regards,
Paulo

[Matt Cramer]

Hi there,

Sorry to bring this up again but I needed to be sure of one thing before commiting...

Are all 88 pin motronic connectors similar...I mean is a BMW M50 ECU plug the same as the one on a S38B38? Broken M50 connectors are somewhat easier to find

Best Regards,
Paulo

We're aware of two types of 88 pin Motronic connectors. You can usually trim one to fit another though...