subaru ecu/ems, subaru engine electronics Options

[ModPR3]

subie guys need your help again. after finding out that a 911 engine rebuild cost over 8k the subie or v8 path is looking good again. if i ran the 2002-2004 wrx 2.0 turbo motor what do i do about the engine control unit or engine management. can the engine be run with the stock subaru ecu or does it have to be switched out to a standalone unit. if the stock ecu can be used, how hard is it to wire into the 914. thanks.

[lapuwali]

The stock ECU can be used. There's at least one conversion done by a person hear who did that, and a great many engines are swapped into Vanagons using the stock ECU. You can also use a standalone unit, and esp. if you're using a recent engine (post OBD-II, so '96 or newer), you won't have to fool with quite as much stuff to "fool" the ECU into thinking it's still plugged into a Subraru. There's also a member here who's done the swap with a Megasquirt ECU, so you'll find help here either way you decide to go.

[Mueller]

Here you go:

Possum Link ...new board that replaces the factory ECU in the box.....not sure off all the years it works with, but a quick glance shows '98 to present.....

The regular standalone Link (which I have) is popular with the Subaru powered sand rails.......

[bondo]

QUOTE (Mueller @ Feb 23 2006, 05:50 PM)

Here you go: Possum Link ...new board that replaces the factory ECU in the box.....not sure off all the years it works with, but a quick glance shows '98 to present..... The regular standalone Link (which I have) is popular with the Subaru powered sand rails.......

$1300!!!

(oof)

[lapuwali]

QUOTE (bondo @ Feb 23 2006, 04:57 PM)

QUOTE (Mueller @ Feb 23 2006, 05:50 PM) Here you go: Possum Link ...new board that replaces the factory ECU in the box.....not sure off all the years it works with, but a quick glance shows '98 to present..... The regular standalone Link (which I have) is popular with the Subaru powered sand rails....... $1300!!! (oof)

Cheaper than SDS with the full ignition (not optional with later Subaru engines, which have no dizzy)...

[Mueller]

QUOTE (bondo @ Feb 23 2006, 05:57 PM)

QUOTE (Mueller @ Feb 23 2006, 05:50 PM) Here you go: Possum Link ...new board that replaces the factory ECU in the box.....not sure off all the years it works with, but a quick glance shows '98 to present..... The regular standalone Link (which I have) is popular with the Subaru powered sand rails....... $1300!!! (oof)

no special wiring harness needed...should be pretty darn near plug-n-play....

man..it was bad enough that us Type IV people are known to be cheap, but you Suby guys take the cake...hahahahaha

[TonyAKAVW]

Type IV cheap? yeah right!

At least most Subaru guys aren't cheap enough to put carbs on our engines...

Then again thats probalby just because that would be more expensive than the stock ECU (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)


-Tony

[TonyAKAVW]

The wiring harness 'conversion' isn't especially hard, it just requires some attention to detail and a really basic understanding of wiring. Basically what you do is find a schematic diagram for the original configuration in a Subaru and then strip away the things you don't need. What you are left with is an ECU and harness that can be put into a 914.

Figuring out what is needed isn't too bad. The manuals for these cars also have sections describing what each item does. For instance a "purge solenoid" is used in emissions controls, and so its something I eliminated. Some items need to be simulated with resistors, such as the fuel tank level sender and fuel pressure sender. Do some research through the three Subaru conversions on this board and see what people ahve done with electronics. There is a fair amount here already on at least the basics of what to do.

In short its doable with a basic knowledge of electronics.

-Tony

[cbenitah]

Tony, you are on the other hand the master of electronics (IMG:http://www.914world.com/bbs2/html/emoticons/chowtime.gif)

[TonyAKAVW]

Well, there are a number of electrical engineers on this board, and once a few more people have gone through the wiring, there will be even more to help with that. I've already helped another member here figure out some wiring stuff with their Subaru swap and wouldn't mind helping out others.

Making up plans or directions is a bit tricky because of all the variations in engines, ECUs, etc. They are all different, but in the end there is a lot that is common.

Once I actually get my car running and all the troubleshooting done I will do my best to publish the schamatics I have made, etc. But that will only work for a 2001 EJ25. 95% will be identical in concept to other Subaru engines, but pinouts on the ECU, colors of wires, things like that will be different. All of those things are easy to figure out by reading through a manual.

On the other hand you can go buy a Link ECU and they even sell harnesses. That requires far less work.

-Tony

[Hydra]

i chose to go with Megasquirt, my thinking behind all this was:
- MS is cheap (250$ including everything you ight use)
-I won't have to fool the ecu into thinking anything, i'll just toss it away
-MS allows for a great deal of finer tuning that i think is impossible with
the suby ECU
-Ms has tons of online support, and that support makes it look easy
on the other hand:
-MS requires a lot of troubleshooting to get it to work
do your reasining and see what fits best your personal capabilities.
good luck anyway
Nick

[DBCooper]

Two biggest problems I see with MS are that I'm not a consistently good solderer, and I know it's inevitable I'm going to end up having to discover where I may have been less than perfect on a country road somewhere, at night, in the rain. Second is that it's not "hardened" the way the commercial systems are for use in the pretty harsh automotive environment. Everything else about MS is super, but I'm sure one of those things is eventually going to bite me. The only solution I can think of would be to carry a spare ECU, but that kind of defeats the spirit of the MS thing.

One other thing. I looked at the Subaru conversion for a VW five or six years ago, and found two different guys in Canada who made wiring harnesses for those engines that were being put into aircraft. If I recall correctly one was in the east, Toronto or Montreal, and the other somewhere in the plains. They were custom harnesses, not cut down stock, with just the essentials needed to run, control and monitor the engine with the stock ECU. The price was US$300-350. Unfortunately I don't have the contact info any more, but it might be worth the time to get in touch with some of the aircraft folks who are doing this same thing and see what they're using.

[d914]

outback offers Link, stinger and then on to the big buck control units.They run about $1300 with a wire harness and a basic map.

[lapuwali]

QUOTE (Paul Illick @ Feb 24 2006, 05:07 AM)

Two biggest problems I see with MS are that I'm not a consistently good solderer, and I know it's inevitable I'm going to end up having to discover where I may have been less than perfect on a country road somewhere, at night, in the rain. Second is that it's not "hardened" the way the commercial systems are for use in the pretty harsh automotive environment.

You don't have to solder a thing to use MS. There are at least three shops that offer fully assembled MS ECUs for under $400 ready to roll. The same places will also sell you sensors, wiring harnesses, etc, to make an MS installation pretty easy. The full up cost for everything would be roughly $600. Not has cheap as $150 + your labor + junkyard parts, but it does involve a lot less labor. This is also about half the cost of most of the other pre-built ECUs, once you include wiring harnesses and sensors.

As for "hardened", MS has been used for years on daily driven cars by quite a few people. It's now pretty solid. No, it's not OEM install and forget for 20 years quality yet, but failures are pretty rare.

[mrdezyne]

First thing would be to figure out exactly what year and model Suby motor you want to run. I have found that cutting down the stock wire harness differs somewhat from model to model and year to year in the same model.

Tony helped me get on the right track with my harness and what signals to create to trick the ECU. Cutting down the stock wire harness is not hard but very time consuming. I too will post my schematic once I have a running conversion to give everyone some ideas of how to go about this... I should have something to show by June-July time frame.....

[ModPR3]

all ways that work sound good but the more i learn about ms the more i like it. this may be a stupid question but ill ask anyways. i would like to retain good mpg while not being heavy on the gas, this is why i have a big interest in a turbo motor. i can run at a low boost flip a switch and run high boost. theres on problem with this is that all the switchable boost controllers do it cut and raise boost, not change fuel maps. ms to the rescue. ms is cheap enough to buy two what if i ran two ms's with different fuel maps so that when i flip a switch i not only change my boost but also the map at the same time. any thoughts.

[Crazyhippy]

I JUST bought a Link for an 03 WRX used for $400... they are out there.

The wiring isn't tooo difficult, have to take a HUGE wiring harness and cut out the stuff you wont need, just following schematics.

NASIOC is a great Subaru community, and has a HUGE classifieds section. (where i got my link from)


RavensbladeHas lots of different wiring diagrams, and ECU pinouts.

As for mileage, dont sweat the low boost high boost thing, lighten your right foot, get good mileage. wear a heavy boot, go really freaking fast.

BJH

[Mueller]

QUOTE (ModPR3 @ Feb 25 2006, 02:46 AM)

all ways that work sound good but the more i learn about ms the more i like it. this may be a stupid question but ill ask anyways. i would like to retain good mpg while not being heavy on the gas, this is why i have a big interest in a turbo motor. i can run at a low boost flip a switch and run high boost. theres on problem with this is that all the switchable boost controllers do it cut and raise boost, not change fuel maps. ms to the rescue. ms is cheap enough to buy two what if i ran two ms's with different fuel maps so that when i flip a switch i not only change my boost but also the map at the same time. any thoughts.

...just run the higher boost and use your gas pedal as the switch (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

Max boost is normally never seen unless you are WOT.......

if you do go with adjustable boost (let's say for valet parking or your wife or kid wants to drive the car) with modern FI such as the MS, it'll adjust for the boost....no need for 2 ECU's

as for gas mileage, at cruise speeds you will not be anywhere near max boost so if you have your settings at 10psi or 35psi, the gas mileage will be same...it's only when you have your foot buried against the floor will the mileage be different....

[Crazyhippy]

(IMG:http://www.914world.com/bbs2/html/emoticons/agree.gif)

[ModPR3]

QUOTE (Mueller @ Feb 25 2006, 02:49 PM)

QUOTE (ModPR3 @ Feb 25 2006, 02:46 AM) all ways that work sound good but the more i learn about ms the more i like it.  this may be a stupid question but ill ask anyways. i would like to retain good mpg while not being heavy on the gas, this is why i have a big interest in a turbo motor. i can run at a low boost flip a switch and run high boost. theres on problem with this is that all the switchable boost controllers do it cut and raise boost, not change fuel maps. ms to the rescue. ms is cheap enough to buy two what if i ran two ms's with different fuel maps so that when i flip a switch i not only change my boost but also the map at the same time. any thoughts. ...just run the higher boost and use your gas pedal as the switch (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif) Max boost is normally never seen unless you are WOT....... if you do go with adjustable boost (let's say for valet parking or your wife or kid wants to drive the car) with modern FI such as the MS, it'll adjust for the boost....no need for 2 ECU's as for gas mileage, at cruise speeds you will not be anywhere near max boost so if you have your settings at 10psi or 35psi, the gas mileage will be same...it's only when you have your foot buried against the floor will the mileage be different....

thanks for the info, im gaining knowledge left and right. if im running a turbo on a subaru or a type 4 engine with FI, and im running at 8 pounds of boost at 4k rpm but then i turn down the wastegate and now im at 12 pounds of boost a 4k rpm will the ecu adjust for this difference and at that time is it in closed loop so thats why it adjusted.