Subaru - OEM ECU or Standalone aftermarket ECU?

[Dan Dryden]

I'm running a standalone ECU on my Type 1, so very familiar with the pro's and con's of using one.

I'm just trying to understand what would be the best option for a Subaru conversion.
Obviously, the OEM ECU will give full functionality of the engine sensors which a standalone ECU may not be able to do. Eg. VSS, torque control, knock and IAC. But you don't get the tuneability of a standalone.

What have you guys gone for and why?

Thanks.

[mack00]

Hey Dan. Haven't finished my conversion yet. I'll stay with OEM ECU. There are several reasons why for me. I already had it with the donor car, cost of a stand alone, proven reliability and so on. I'm not a racer so stock is fine with me.
I guess it really comes down to your needs and budget. If you need performance go big turbo and aftermarket ECU.
Good luck and have fun.

[ttriebler]

Hi Dan, for my money I would go stock ECU everytime. Failsafe, uses all sensors, perfect maps for that engine, etc etc. There is complete tuneability of most Subaru ECU's using openecu software (free) and a tactrix cable (cheap). You can easily save your standard maps and then reflash tuned maps. I think this gives the best combination however, tuning takes longer because (as far as I know) you cannot adjust the maps live on the car while you are on the dyno. You have to make adjustments to the map and reflash, then do another dyno run.

[jrobe]

What year are we talking about? US or JDM?

Jeff

[Dan Dryden]

I haven't bought anything yet. I'm still at the planning stage of my conversion and will need to sell my type 1 efi turbo engine and upgraded trans to fund it.

I'm in the UK, so likely to be UK or JDM.

Advice on a donor car is welcome! From what I've read so far, aiming for a late model up to 2004 would offer me the most "safety" features with regards to engine monitoring from an OEM ECU and also variable cam timing......

But I'm at the bottom of my Subaru learning ladder, so please let me know if I'm barking up the wrong tree.

I'm after the most power possible from a standard engine and turbo, which I believe is around the 280bhp mark.
Plus there's also the line of thinking that a younger engine is less likely to pop!

I then just want to enjoy it as a road car with the occasional track / circuit day.

[ttriebler]

Yep up to about 2003/2004 is the way to go. Just beware that in the U.K. they want to CANbus around 2003ish...you will want to avoid CANbus setups as they won't run outside their native Subaru environment. You should be able to get a nice 2002/3 STi with a factory 280hp. More power than you could ever want in a beetle captain wheelspin

[Richard Olafsson]

For that sort of age I think stock ecu and then ECUTEK if you want to modify... I went stock with ESL daughterboard which is live map-able with all stock functionality plus more

[panel]

I'm going stk ECU fwiw.

[Dan Dryden]

Thanks for the feedback guys. Looks like standard ECU is the way to go.

[ryans88gt]

I am planning on using microsquirt since the wiring is pretty easy, the tuning is pretty easy, and it seems pretty universal. There are a lot of little things to sort through though.

I'll report back on how well it works in like a year when I finish this project.

[63 Bug]

I'm going for Megasquirt 2, but thats because it was already fitted to the car when it was aircooled running ignition, so it simplifies my install, and I didnt have a donor vehicle/ecu I could use.

I can still run knock/launch control/flat shift, the only downside is having to tune it, although I'll probably get a basic map sorted using TS live analyse, then stick it on a dyno...

[volksbugly]

The Subie crowed have cracked the stock ECU. You can tune it.
www.youtube.com/watch?v=e1X43SWtHhM

With that said, since your megasquirted and if I was in your shoes, "which probably in 7 years I will be ready to replace the aircooled engine" I would stick with Megasquirt. Its only getting better. You could even make a harness that goes from the stock ECU plug to the megasquirt, or just wire every thing up custom to the megasquirt which will be cleaner. (MS can do VVT)

Also you can look at subaru tunes and just plug in the maps to megasquirt.

[Dan Dryden]

The Subie crowed have cracked the stock ECU. You can tune it.
http://www.youtube.com/watch?v=e1X43SWtHhM

With that said, since your megasquirted and if I was in your shoes, "which probably in 7 years I will be ready to replace the aircooled engine" I would stick with Megasquirt. Its only getting better. You could even make a harness that goes from the stock ECU plug to the megasquirt, or just wire every thing up custom to the megasquirt which will be cleaner. (MS can do VVT)

Also you can look at subaru tunes and just plug in the maps to megasquirt.

Looks like you can tune a stock ecu!

I'm not already Megasquirted. I use an Emerald ECU and plan to sell it with my engine to increase its saleability.
That's why I asked the question on here about which ecu I should choose for the Subaru conversion.
It helps to know these details so I know whether to search for a donor car or just a donor engine and gearbox.....
Donor car seems to make more sense to me.

[56SemaRag]

You don't need to go aftermarket. There is a huge amount of support for opensource ECU flashing and mapping. All you need is to check out RomRaider to see if its for you. I don't see a need to drop AVCS and the outstanding built in knock correction of the stock ECU. I have flashed mine several times changing all the maps needed with the Tactrix dongle and a laptop with no issues. Even if you do end up bricking your ECU, they have had several success stories of un-bricking them.

[volksbugly]

Megasquirt just came out with a PNP system http://www.diyautotune.com/catalog/mega ... p-599.html. I'm not saying get that because making your own wiring harness is still going to look nicer, but you can see the additional features you get in the lower part of the advertisement.