Jump to content
Ultimate Subaru Message Board

building an ECU


Recommended Posts

I have a friend who has the gear to build me an ECU and hes out of work with a bad back so hes bored.

 

I was wondering if anyone has done this for their loyales and if its even possible.

 

I have a regular 1991 Subaru Loyale, EA82.

 

Is there a website I can find blank ECUs at or is there a place I can get a pre-programmed ECU. I want my car to be faster and I have some money to burn but no skills.

 

thanks alot.

Link to comment
Share on other sites

Megasquirt WebSite:

http://www.msefi.com/

 

And major USMB thread about it:

http://www.ultimatesubaru.org/forum/showthread.php?t=19123

 

IIRC, the ECU uses a 6502 uP (might be 6809... been awhile since I looked and it was an 85 ECU). If you wanted to build a new ECU that used a more modern processor and used the existing pinout/wiring, that would be interesting.

Link to comment
Share on other sites

I had one apart to get close look.. they seem to be .23 micron chips (last quite a while-- like an early 90's PC). The clock seems to be replacable if right hertz is found. To get a new "shaker" with more modern discipline would be interesting for longevity, precision. there has been changes on our own modern pc after the loyales were built on the "clocks" allowing for huge multiply (lots of gigahertz). I would assume it to be the a nice upgrade for a simple ecu. I found the similar hertz on an old diamond sound card for my pc from 1997-- got me thinking ,a 4 year newer clock on .23 micron chips .:)

If ecu is not .23 micron chips, could someone inform me?

Link to comment
Share on other sites

I want my car to be faster
you have to realize what you're starting with. i think you'll be very disappointed with the results of even the best possible ECU upgrade. you'll smooth out idle and driveability and improve gas mileage more than gain performance (and even those improvements will be minimal). i would bet money you'd get more gains with a thorough tune up (realize the injectors and everything else is 15 years old), plugs, wires, coil, air filter, and playing with the ignition timing than you would with upgrading the ECU on an NA engine.

 

these cars are slow and the ECU is not the solution.

Link to comment
Share on other sites

 

these cars are slow and the ECU is not the solution.

 

Some of these ecu's will be turning 20 soon. There is in fact things to tinker with. A newer clock isn't a bad idea on the old monster micron chips. I inadvertantly stopped constant pinging even on bad gas, with a 10ohm resistor at R1 (lead resistor - first thing to get zapped while playing with gadgets under the hood :mad: )on the board. Clock gets shaky at first, then dead-- when? the older ecu's will tell for sure. If to increase the clock hertz, I would be confident on a bigger resistor at r1 to get away with it (try at home at your own risk -- I think I am going to). All wiring taking more than 60 hertz is taking a beating. I proved it to myself with killing speaker wire on a big radio (similar beating as ECU circuitry).Time will reveal it...:confused:

Link to comment
Share on other sites

ive got no clue what you just said.

 

It doesn't really make sense to me either, and I have some knowlege in the area of electronics and microcontrollers.

 

I would tend to agree that you won't get much performance improvement by upgrading the ECU. But, yes, computers are faster these days and a faster ECU with appropriate programming might be able to do some more complicated modeling of the engine physics and do a bit better job.

 

But simply putting faster clock on the stock ECU is unlikely to help it at all. The original speed is already sufficient to handle the original calculations.

Link to comment
Share on other sites

It doesn't really make sense to me either, and I have some knowlege in the area of electronics and microcontrollers.

 

I would tend to agree that you won't get much performance improvement by upgrading the ECU. But, yes, computers are faster these days and a faster ECU with appropriate programming might be able to do some more complicated modeling of the engine physics and do a bit better job.

 

But simply putting faster clock on the stock ECU is unlikely to help it at all. The original speed is already sufficient to handle the original calculations.

 

I was simply stating I had a heavy clock (large physically for a clock) at similar speed- just a bit faster, for repair if need be. That generation didn't have the micron level nor precision of today, however minimal it may be different now- 20 years for a clock in my car that starts at -25 F, had 2 bad alternators, all the battery changes in 13 years and outright short circuits zapping ECU resistors, got me thinkin... An ECU permanent disaster is imminent. Something to think about...I agree about no upgrade. After checking on "new ECU" for a loyale @ 700 bucks...my soldering gun and old pc parts are standing by like they have already to bail my ecu failure out on my own.

My pc had a clock that "swayed" and verified with an age old unix prog and comparison to nuclear time servers. The car and its extremes, including all the different speeds it travels and stops must be torture on the clock in comparison to a pc.How the 88's or late 87's with these ecu's are still running must be fantastic engineering that I hope I am doubting for my own pessimism.:rolleyes:

Link to comment
Share on other sites

86 was the first year for subaru SPFI. MPFI was already being used in the US market in 83 on the EA81 Turbo.

 

GD

 

no 1986 here had it. My 1987 was considered the last of the mechanics car (simply carbed)- as 1988's were first around here to get ecu's and injection from there on out. I am assuming to blame demographics/economy for low population of maine getting the first of anything.If it had the bug lights it was ecu originally, four headlights- always a carbeurator original, thats how I learned them. Interesting sube info about 1986- :)

Link to comment
Share on other sites

Headlights don't really play a role - for EA82's that's a GL/DL thing, and I've seen plenty of 87/88/89 DL's with four headlights and SPFI. SPFI and MPFI in 85/86 was exclusively a 2WD thing except for the turbo models, and the XT. At least that's been my experience. There's an 86 GL-10 2WD sedan in the yard right now with SPFI, and I've got pictures of an MPFI non-turbo 85 wagon. Both with single headlights as they are GL's. I also own an 87 2WD SPFI coupe.

 

GD

Link to comment
Share on other sites

So there is in fact 20 year old ecu's out there running.... I feel better about a few more years and not doubting it. :) I am still startled at seeing a 1988 with mpfi -- some folks and thier areas must have been in on the cutting edge of subaru evolution (west coast perhaps?). It is not where I am at all. In fact to go to the dealer now is to find a pile of plane jane wagons and even the hood scooped turbo subes are mellow-- I have yet to see the blue wrx sti anywhere on the lot (I have never seen one up close - unless I was towards southern new england, or someone passing through my area). Ahh to live in the hicks - one man's junk is yet another's treasure.

Link to comment
Share on other sites

Please sign in to comment

You will be able to leave a comment after signing in



Sign In Now
 Share

×
×
  • Create New...