7 replies to this topic

[crjohnson]

So I'm not far off finishing building my spare ej25 engine (going in my 2003 gen 3 outback) which has a few mods (delta cams, equal length 4-1 headers, porting, big plenum-long runner intake manifold).

 

I'm now wondering if it would be worth converting my ecu to a newer gen4/2004+ ecu and wiring loom so hopefully one day it can get remapped by throttlehappy and get the full potential from the cams etc.

 

Also it would be cool to get the fuel economy display from a gen4 liberty, OR somehow wire it all up to my 2011 Subaru Kenwood NAVI headunit (displays all that engine info, MIGHT be a CANBUS system though?). OR install a nexus/android device with the Torque app?

 

BUT I realise this would mean converting to the drive-by-wire throttle body and pedal, probably the only/biggest downfall of the conversion, throttle lag?? 

 

Can anyone think of much else that would potentially make it very difficult or not worth the hassle? Fuel pump differences? I've red somewhere that some cars have a variable speed type fuel pump system?

 

I also realise I'd need to install the 2nd O2 sensor in the exhaust (easy) and already have wiring diagrams for a 2007 Forest with the ecu and loom plus diagrams for my car.

 

Cost: about $100 for the loom and ecu from the wreckers..

 

Potential immobiliser issues??

[crjohnson]

Cancel the Kenwood headunit engine display idea, it does run on CANbus..

[Robert]

Best Speak to al at Amauto about it

I believe gen 4 is canbus anyways so that would be a mind fork to wire up


Best option is to go standalone ecu imho

[Barbbachello]

I believe gen 4 is canbus anyways so that would be a mind fork to wire up

IIRC only Post facelift is canbus

[crjohnson]

a quick google told me that canbus became standard around 2007-2008? But also some cars had it for abs and other non-engine related stuff.. 

[RX25SE]

Either way, I can see this being a head fk to work out.
Cost vs benefit?

[crjohnson]

Yea I'd expect it not to be that easy, I once did a full engine and loom conversion in another car years ago so kinda know what I'd be in for..

 

Benefits: - remap'able, would be great to tune it for the cams etc. Romraider? Learning view? Tactrix cables?

               - OBD2 compatibility with most good programs/apps (Torque?), would be nice to know what the engine is doing in realtime. Current ecu is only obd1 (I think..) and barely works with FreeSSM

               - all standard idle, cruise control stuff will remain as per normal (I'm pretty certain cruise wont work with a stand alone ecu, possibly will with a piggyback though)

               - the intake manifold I am going to use is off a 2006 forester and already has the throttle body, injectors, ignition coil, fuel rails etc. Also has the TGV's but I've already ripped the plates and sensors out ie. TGV delete style. I also think they are WRX style injectors.

 

Cons: - cost, approx. $100, possibly slightly more if I need to buy a new o2 sensor.

           - wiring fun times

           - immobiliser issues?

           - electronic throttle body and pedal assembly

[Beckers]

 

 

 

 

Fuel pump differences? I've red somewhere that some cars have a variable speed type fuel pump system?

 

 

Gen 3 turbo cars have a fuel pump controller, that slows the pump down when not on boost etc. This is controlled by the ECU.

Stay away from drive by wire. As other have said, stand alone ECU might be the best way to go.