EJ20G "RobTune" Info

[cj91legss]

Yes it is the Jecs ECU, Sorry I should have been more specific in the first post.

Pics of the ECU board and ECU Case

[Legacy777]

CJ,

Thanks for the pics and info!

Just to add to what CJ has posted, you need a JECS ECU from a 92-94 Legacy. The 90-91's were different and did not have the middle holes for the heat sink to bolt to. You could drill them, but if you're looking for a plug & play setup, go with the 92-94 non-turbo JECS ECU case.

[ScottyS]

Well, today I was finally able to get a Robtune ECU into my car. I have the 440cc's, the JECS MAF, a TD04, and stock EJ22T block and heads. This car has been running an early Revtronix since they first came out, but the driveability always suffered with jerky transitions between fueling modes. I had conditioned myself to drive it well, but it was never "right" the way I wanted.

After waiting for Rob to perfect his process and design, I asked him to do me up a tune on the EJ20G ECU and make me a spark adapter while he was at it. Rob's a lot like me and doesn't have a lot of spare time, but the wait was worth it.

After getting an 92 NA ECU case to hold the EJ20G board, the installation was practically drop-in. I followed the instructions in the "Adapting the Ej20G ECU" thread and the "Modifying Spark Adapter" thread for de-pinning and combining the adapter to the harness. It honestly was tremendously easy, once I figured out how to de-pin using a safety pin. It took about 1.5 hours going slow from pulling the car into the garage and driving it back out again for a test spin.

After just a short drive, I am amazed at how smooth the transitions are and well the car pulls. It really feels like driving OEM smooth now, the car feels completely different. I'll post more comments once I've got some miles done, but right now I can't thank Rob enough for taking this problem on and finding an elegant solution.

[Lego22T]

Very cool!!! I don't any of us can thank him enough for giving us some sort of PnP solution to the hassle of owning an OBD-I vehicle and not being able to simply plug in a Cobb AccessPort and make all of our mods work with the car.

[MikeyMeyagi]

i dont know if this has been mentioned, but i was installing one of robs 20g boards into a jecs n/a ecu, and on comparison of the boards, i cant find a difference. it even has the 28 pin socket for the external rom chip..... rob have you looked into chipping the n/a ecu?

[cj91legss]

As far as i know josh or another board member is sending him an na ecu for some diagnosis. It would be awesome if rob was able to crack them as well. Could make affordability easy as hell.

Sent from my SGH-T989 using Tapatalk 2

[kimokalihi]

So Rob thinks it may be possible to chip an NA ECU instead of an EJ20G? Sweet. Doesn't help me a bit. I just need to go COP already.

I have a good question. If I go to COP with WRX coils is it still necessary to mess with the harness? I don't know what I have to do to go from EJ20G w/dual ignitor conversion setup over to WRX coil-on-plug setup.

[wtdash]

If I go to COP with WRX coils is it still necessary to mess with the harness? I don't know what I have to do to go from EJ20G w/dual ignitor conversion setup over to WRX coil-on-plug setup.

Kimo,
I believe page 13-14 of this same Thread will help answer this question.
Td

[Legacy777]

I gave Mike a non-turbo JECS ECU to give to Rob when he sees him. Rob will take a look at it and see if he can do anything.

[Lego22T]

Like Kimo stated above, the modification of the EJ22E ECU won't be a benefit t me, but it would surely help out those who want to do this mod on the cheap or assist those who have an N/A Legacy and want to turbo it.

[rob]

After just a short drive, I am amazed at how smooth the transitions are and well the car pulls. It really feels like driving OEM smooth now, the car feels completely different. I'll post more comments once I've got some miles done, but right now I can't thank Rob enough for taking this problem on and finding an elegant solution.

Thanks for the feedback Scotty. I am glad you are happy with it. And yes, I am busy busy busy and not always the best at responding to forum posts, PMs, emails, carrier pigeons.... Best advice is to email me directly, keep pinging me, and don't take it personally if you don't hear anything for a while.

i dont know if this has been mentioned, but i was installing one of robs 20g boards into a jecs n/a ecu, and on comparison of the boards, i cant find a difference. it even has the 28 pin socket for the external rom chip..... rob have you looked into chipping the n/a ecu?

Yes as Josh mentioned I am slightly optimistic that those NA ECUs have the same components as the the ej20g ecus. If this is true, then I can stop trolling ebay UK for ecus. Thanks to Josh for bringing the spare ECU with him on his visit to WA. I will be meeting up with MikeT soon to deliver his tune and pick up the NA ecu to try.

I have a good question. If I go to COP with WRX coils is it still necessary to mess with the harness? I don't know what I have to do to go from EJ20G w/dual ignitor conversion setup over to WRX coil-on-plug setup.

If you have the right heads to fit the COP, then it would be a matter of running some new wires to the COPs; one each from the ECU and a common Batt+ wire to all four. You wouldn't use EJ20G coils, but instead jump straight to the GD coils. They will need a ground wire but that can run from the coil to the mounting bolt. You can eliminate the 4to2 adapter, stock igniter and plug wires this way.

-Rob

[kimokalihi]

They're ej20g forester heads which were wasted spark to begin with and I'm pretty sure don't have the cop mounting bolt holes. Will this prevent me from using wrx cop?

[mike-tracy]

Look under there Kimo, I'll bet you'll find a bolt hole for cop.

[rob]

I had a chance to try out the NA ECU (thanks to Josh the pusher and Mike the mule) this weekend and unfortunately the news is not good. It took the EJ20G chip and on the bench it looked like it was running ok which was encouraging. I did notice however that it was running batched injection (paired injectors firing simultaneously), whereas the EJ20G ecu runs sequential injection. I am not sure why that is, but I took it as a bad sign. My suspicion was correct in that the car wouldn't start. So at least the version I got from Josh (with the extra riser board) is a no-go.

-Rob

[mike-tracy]

Got my Robtuned car running! Couple of per-existing issues I need to work out with my wiring, but with the MBC set to 12PSI it pulls way harder than the Z4 ECU did at 14 psi. Cant wait for my car to run properly and test the tune out at 18psi!

[Lego22T]

That sounds awesome Mike!!!

[ScottyS]

Sweet!

[kimokalihi]

Mike, did the robtune ecu solve your spark fuel problem?

[mike-tracy]

Mike, did the robtune ecu solve your spark fuel problem?

nope. I wasn't expecting it to, but I was hoping it would.

[MikeyMeyagi]

bummer the n/a ecu didnt work with the 20g chip.... any way to make a chip that would work with it though?

[kimokalihi]

You swapped the chip yourself or are you saying rob figured out he can't make chips for the na ecu?

[rob]

bummer the n/a ecu didnt work with the 20g chip.... any way to make a chip that would work with it though?

You are funny Mike. How about I add that to the list of stuff that I am already not getting done

Kidding aside, I am guessing there are differences in one of the big chips that I can't do anything about. It is weird that it tried to run in batch injection mode. I didn't think any subaru did that. It might just be an artifact of something else not being right.

[Lego22T]

It is a shame that this doesn't look promising for the N/A ECU. Glad I have a JDM model to be modified!

[mike-tracy]

I have a feeling that there are way more ej20g ecus floating around than SS's, so we should all be set as long as rob keeps making. chips.

[rob]

There is no shortage of EJ20G ecus, it is just that they are scattered across the world. UK is my best source, but still a pain.

The good news is that at least someone has found a cheap solution for easy ecu mounting.

-Rob