EJ20G "RobTune" Info

[rob]

Mike's dyno and 1/4 mile results are posted here;
http://bbs.legacycentral.org/viewtopic. ... 46#p341246

Nice to see that the launch control had a very positive affect on dropping the 60' time.

-Rob

[rob]

Hey all, I have another small update. I received my first run of boards for both my ignition converter and my own ej22t chip board. The bad news is that when started assembly of the ignition converter I found that there was an error in solder mask for on of my surface mounted components. It turned out to be a problem with the software and had to have the boards respun. Hopefully I will have those next week and I can get back to experimenting on Drew's car.


In the meantime I can start assembling my chip board (dang this thing needs a catchy name) and will plug it into a stock ECU to verify the design is sound. Then it's on to reversing the code. Can I mention again how much of a PITA it is to get to that damn ECU!

-Rob

[kimokalihi]

You said it. ECU is a bitch to get out. Also wasn't fun trying to mount the EJ20G ECU which had completely different moutning brackets.

[rob]

I think I came up with a pretty good way of installing the G ECU in the stock legacy location. I will have to post those pictures in my adapting the EJ20G thread.

-Rob

[farfrumwork]

Anything to report as of late?

itching to get a rob chip in my '93 (and the 22T ECU would be prefered)

[rob]

Sure I have an update to share.

After a blue wire fix, my EJ22t add-in chip board is done and works as expected. Right now it does nothing more than run a chip with the stock tune on it Reversing the stock code is the next (painful) step.

I ran some experiments with my 4to2 ignition conversion final proto board. It seems to run fine, however when looked at the signals on my scope, I wasn't happy with what I saw. After several experiments I have decided scrap the current design and go to redesign number three. So that it is WIP again....

-Rob

[Florin1]

Hey Rob. Any news on the ignition conversion for us guys that are gonna be running the 20g ecu yet?

[logan9691]

Well after 9 hours of injector swapping, MAF swapping, fuel pump swapping, ECU swapping and some stupid f^%^ing trouble shooting on fuel pump issues (wouldn't run) and some other stupid issues I got my 20G rob tunned ecu in today and the car starts and runs great so far, got some things to clean up still but off to a good start

Thanks Rob you do some good work.

- Logan

[farfrumwork]

Sounds good Logan,

You have a EJ22T in your SS right? Let us know how the chipped 20G ECU works out for you. (Trying to decide if I get a chipped 20G ECU or wait for a chipped 22T ECU...)

[logan9691]

Yes I do, stock EJ22T, front mount, sti turbo, 550 injectors, Apexi intake, Greddy EBC, 3" exhaust (going to up-grade to Invidia g200 turbo back soon) and a bunch of other things.So far so good. Only "issues" (if u wanna call it that) is when u start the car the idle will jump around a little (has stalled because of it a couple of times) but once u drive it a little bit (down the road) it is fine the next time u come to a stop. IDK if Rob can give any insight into this, if it is a symptom of a chiped ECU or the fact that it is in a car that it isn't suppose to be in.

[rob]

Yes I do, stock EJ22T, front mount, sti turbo, 550 injectors, Apexi intake, Greddy EBC, 3" exhaust (going to up-grade to Invidia g200 turbo back soon) and a bunch of other things.So far so good. Only "issues" (if u wanna call it that) is when u start the car the idle will jump around a little (has stalled because of it a couple of times) but once u drive it a little bit (down the road) it is fine the next time u come to a stop. IDK if Rob can give any insight into this, if it is a symptom of a chiped ECU or the fact that it is in a car that it isn't suppose to be in.

Hey Logan,

No, it is not normal behavior of the chipped ECU. It should idle as smooth as stock. I would start by looking for a vacuum leak (including at the injector spacers and o-rings since you recently replaced those). Also the MAF might be a little dirty. It will affect low speed readings more so.

Also, the knock light flicker is normal as the ECU goes through it's normal learning process. You should see them every now. If they happen more often and for a longer period, then you should back off and start troubleshooting.

-Rob

[logan9691]

bump!

Hey Rob,

you got any future plans for something new?

[wtdash]

Bump....may need one of these......

[CFK]

Me Too !!!

So is there a EJ22T version coming or will the EJ20G work just fine

[wtdash]

Me Too !!!

So is there a EJ22T version coming or will the EJ20G work just fine

Uh...please check your Signature!



TD

[CFK]

Done, beat myself up

Should have edited that since I ended up reading most of the thread after posting.

I just installed a MBC and was about to install the fuel cut defender, might just hold off then if this might be ready in the near future. I keep buying parts faster than I can put them in anyway, so I got time. Time to save up and find a cheap TD05-16G, Jecs MAF, injectors and Walbro.

[logan9691]

Man i love this ECU, runs a 22t like it was meant to be run

[cj91legss]

i think i need one of these

[kimokalihi]

Why? What's wrong with your piggy back?

[cj91legss]

nothing just haven't worked much on it since i started making the harness.....

[MikeyMeyagi]

I bought a Hydra Nemesis 2.6 for the legacy...... Dont get me wrong, I LOVE my 20G ecu..... BUT i want to go with a 30R and Rob said hes not going to be doing a MAF and injector upgrade for some time. On the bright side, I get to put my MAF in the garbage since the Hydra is MAP based

[logan9691]

I bought a Hydra Nemesis 2.6 for the legacy...... Dont get me wrong, I LOVE my 20G ecu..... BUT i want to go with a 30R and Rob said hes not going to be doing a MAF and injector upgrade for some time. On the bright side, I get to put my MAF in the garbage since the Hydra is MAP based

Oh I totally agree, with the current state my car is in and even when the new motor goes in, the 20g ECU is exactly what it needs, but down the line when I'm ready to go MAF-less and run 900-1000cc injectors, gt35r turbo, external waste gate, more aggressive cams, etc. etc. then I'll go and buy a hydra or something equivalent. But what Rob does with these ECU's and how easily they can be altered to run on our cars, with minor modifications, it is an awesome option for those, like myself, that have already maxed out the stock ECU, but aren't ready to go all out.

[MikeyMeyagi]

its a awesome ecu and tune. ive got nothing but good things to say about rob and his tune.

[rob]

its a awesome ecu and tune. ive got nothing but good things to say about rob and his tune.

Thanks for the nice comments guys. Have fun with the Hydra. From my experience, you will find tuning a MAP based system a lot more...um..."enteraining" than tuning for a MAF system. I certainly don't want to go back to MAP anytime soon.

Any word on how your buddy's duplicate build is running?

UPDATES
I do have some updates to share on the small progress made over the past couple of months.

1) EJ22T tune: I have disassembled most of the stock ECU code (with some help from the Nissan tuning crowd) and have been making slow progress on reversing the code. So far I think I have two ignition maps, main fuel map and the MAF transfer table identified. My next steps are to work out the main engine params and looking at some of main algorithms.

I do have a couple questions for the community. I think I read somewhere that the two ignition maps are for normal and knock detected. Did revtronix ever expand on how these interact? Second, I remember reading that in the early version of the revtronix SSM logger, the ram address for the engine parameters were listed in a separate config file. Does anybody have that listing? It would help speed things up for me.

2) 4ch to 2Ch ignition converter: This one has been taking more time than I thought. I had my test vehicle running my first prototype for a while in late summer. All seemed fine on the surface and in fact I had purchased parts and fabbed circuit boards. After some careful testing I wasn't convinced that the ignition timing wasn't being affected and ended up scrapping the design. I am now on my 3rd (or maybe 4th?) redesign and early tests look like that problem is solved. After the new year I returned the the test vehicle to the rightful owner and now will focus on setting up a good test bench for out of the car ECU testing. This will also help considerably in reversing the ECU code. The expectation is that all will be in good shape to take loan of the test legacy again (as long as Drew has the stomach for it again ) and have everything finalized.

3) EJ20G tune.: Nothing new to report. The few EJ20G tunes I have sold for EJ22T motors look great and everyone seems happy with them. In my opinion, this is still the best option for you guys if you can source the injectors, MAF and figure a way to change over the ignition.

-Rob

[dscoobydoo]

You are always welcome to re-borrow the car Rob.
And since I have a few 20G ECUs on the way, you will need the car back again anyway.