Motronic? MORONIC! 325es Rev Limiter

[Delraco]

Actually, I'm the moron. But that's not surprising. After doing some research recently on the differences between the different motronic versions available in the e30 world, I have a few questions.

Here's the skinny:

WHAT I HAVE
-1986 325es 4/86 build date.
-885 hardware itching to get used/abused.

WHAT I'M DOING
-The original plan was of course to go motronic 1.3 and do the "327i" swap of yore.
Plans change. I do stupid things and then have to deal with the consequences.
Now the plan is to use the stock "e" ECU, wiring harness, spark plug wires, crank pulley, sensors, shortblock etc.........with a late model "i" head, intake, throttle body/TPS, icv, AFM, injectors, FPR.

WHAT I NEED
This setup will work fine...theoretically. I'll still have to sort out exactly what hoses I'll need for what, which has gotten me slightly confused being that I don't know if I have the heater recall and I'm using an early model block and cooling system with a late model top end. Whatev. You didn't need to know any of that, no biggie.
What you do need to know is that I want my car to rev up to 6500rpms and be able to take advantage of the bigger "i" injectors. I also wonder if there will be any problems since there's no more cold start injector (which my early motronic will be expecting.)


Anyway, please give me some feedback. Is there a preconfigured chip for early motronic that will take advantage of the bigger "i" injectors, account of the 6500 rev limit, and the cold start injector delete? Will there be any other issues caused by using early motronic with my late model 325i hardware up top?

yarrr I'm annoyed. I can't really spend much more on this setup, this is uber budget and I'm selling it immediately after getting it running right. So yeah, it needs to be fun and reliable even if it isn't 100% of what it COULD be. halp.

[Varinn]

It will not work, the injectors on an early eta motor are very different than an i motor, and not just in the output. You will also not likely get the higher rev limit figured out and you're effectively trying to run an i motor as an eta. The intake, ignition timing, valves, cam duration, fuel mapping, exhaust, etc are all VERY different. You will most likely take a significant power loss in all rpm ranges. I know this has been done before, and it "works great man" according to some but I've driven these setups before and felt the car was noticably slower than a chipped eta or stock 325i.

A harness and dme can be had for cheap to make your car halfway proper

[Delraco]

Thanks for your input. You clearly understand the differences between the various motronic versions a lot better than myself.

I'll wait then, and get an "i" harness and crank pulley. That's really all I'm missing..I actually have an "i" DME already...feh

One more question:
After having put everything together nicely (stock "e" block, stock "i" top end + ECU), am I correct in guessing that running gen III 19# injectors will not yield much if any oomph over the stock gen II's untuned?

[thebutterson]

I think you can make it work, but it's better to just do the motronic 1.3 conversion. Once you have the head off, getting the harness out is pretty easy as everything is readily accessable.

To me it's wrong to say it "won't work". The injectors are different between e and i, in flow rate, and the fact that the e's use low impedance vs high impedance in the i. I think the e injectors actually have larger flow capabilities but I can't say for sure. If you pull the numbers off the injector you can search for them. As long as your injectors match what your ecu is set up for, the only difference should be tuning the ecu to match the new capabilities of the 885 head.

However, I would still push for the 1.3 conversion, iirc it has a larger afm that you want to take advantage of the engines capabilities. You'll also want the i throttle body.

Here's a good thread from e30 tech on motronic tuning, I'm pretty sure the guy was tuning the same basic setup you're going for.

http://www.e30tech.com/forum/showthread.php?t=98922

[Delraco]

I was not aware that the "e" used low impedance injectors or that the flow rate differed at all. Looks like I have more homework to do, thanks for the link :)

But the warnings shall be heeded. Motronic 1.3 is in the car's future then. I spent my free time today prepping and installing the 885 head on the eta block, installing the water pump, timing belt, pulleys, etc. So I won't have to massively change direction on my project or anything, it's just an extra trip to the junk yard to grab a harness and a crank pulley which means I'll have to open up my already too lightweight wallet again.

Mostly I'm just a whiny ass hat.
I actually have nearly all the necessary components, just a few epic shitty setbacks have disillusioned me as far as this project is concerned.
I'll rally the troops.

[Delraco]

Setback #1 being...

http://www.e30tech.com/forum/showthread.php?t=107574

lulz were had

Halonine's post was deleted, but he claimed his two year old son died the same month he got thrown in jail and rolled his GTI. None of which were related incidents. He then proceeded to - almost sobbingly - beg e30tech to never buy from him, cause he's just too unstable...UNSTABLE MAN *sob


So yeah. oooooooooookay. I just wanted some engine parts, not the Maury Povich show.