Are the rev limit of the jdm n/a ecu's any higher than the usdm ones? (OBD 1 specifically) The reason I'm asking is because I'm running my 2.5dohc on my 95 1.8 ecu and it runs fine, but doesn't really wake up until around 4k and is still pulling great to the rev limit. I'd really like to have another 1k to rev to, but the guys charging to mod the ecu's (if you can get ahold of them) charge so much you might as well get turboed. Anyone know about this or have a raised rev 1.8 ecu? Thanks for any help



B

I want to spin higher.. so bumpdoziddlyump , still no one knows?

IIRC the EJ204 revs past 9k. Check into the older EJ20R also.

The 99+ only goes to 7100-7200. It rev cuts from there.

interesting info. I wonder why those ecu's aren't offered for sale anywhere or ever mentioned, at least I haven't seen anything about them so far. It would be awesome to use one, and having one for a larger engine than the 1.8 would probably be a plus. Hey redwagon, how's it going? I still haven't tuned my emanage, I'm waiting until I get all of my transmission and suspension stuff swapped in, now I have to wait 7 to 10 days for my bike parts to come in so I can ride it until I get the car finished.

Look into a 96 Legacy Outback ECU. See if the pinouts work out with your pinouts. On my 96 Brighton, I have to move one O2 sensor sheild pin to allow the 98RS ECU to p&p with my harness for an instant 6500 revlimit.....before hacking.

Or...try contacting a guy named Keith at (305)232-0460. He advertises revlimit raising for most cars ($100) in the back of some magazines. I took a chance with a spare 98RS ECU and had him try for a limit of 8k. I got it back a couple days later and all has been well so far. I told him I didn't wanna go any more than 25% over stock which would be 8125rpm. 20% is 7800. We're somewhere between the two....I don't have time to watch the tach and I rarely stay there for more than a few seconds. This is on a prepped 98RS.

Your OBDI ECU should be no problem for him and much cheaper than sourcing a JDM unit.

Jay Storm

IIRC the EJ204 revs past 9k. Check into the older EJ20R also.
EJ20R's are Turbo though. Do you mean older EJ20-R? Which would be EJ20D's I guess. I really dislike that on subaru's site they refer to the EJ204 as an EJ20-R, and do the same for the EZ30D, calling it an EZ30-R. It's just more confusion.

I think the EJ20D only goes to 7k rpms though.

The EJ20-R is the recent N/A 2.0 Legacy motor

Jay, I assume this rev limit raising is the overclocking your referred to in another thread? Interesting (and tempting) stuff...

Pat

I think I would like to stay around 7 or 7.5k, although I may get bored with that. Mine's at 6k right now and the engine wants more. Even 6500 would be helpful. I am looking now for something around 7k, maybe I'll contact the guy you referred to, Storm.

This is an EJ204: http://page5.auctions.yahoo.co.jp/jp/auction/e58105489

There was an earlier dohc 2.0 n/a EJ20 that revved to the moon, I was pretty sure that was the EJ20R, but now I see info about BF5B Legacies... looks more like a variant of the EJ20G, probably that twin-turbo monstrosity. You're probably right about it being the EJ20D. The best specs I found on that are 150ps @6800rpm, so it does rev a bit higher than the USDM stuff. *sigh* I wish they could keep their engine codes a little tidier...

Word, EJ204 is pure sex.

Yeah, the phase I DOHC 2.0 NA was the EJ20D, in the last few years the website has been calling the phase II DOHC 2.0 NA's EJ20-R's. The engine code is still EJ204 I believe. Did the same with the AVCS EZ30D calling it an EZ30-R, and now everyone is calling it that! Why they are doing this is beyond me. The actual EJ20R was on 96-98 manual GT-B's and RS's

Mmm. Japan wikipedia has an n/a EJ20 doing 190ps @ 7100rpm (http://ja.wikipedia.org/wiki/%E3%82%B9%E3%83%90%E3%83%AB%E3%83%BB%E3%83%AC%E3%8 2%AC%E3%82%B7%E3%82%A3), which is more in line with what I remembered. No year on that, but it's an AVCS model so it can't be very old...

Mmm. Japan wikipedia has an n/a EJ20 doing 190ps @ 7100rpm (http://ja.wikipedia.org/wiki/%E3%82%B9%E3%83%90%E3%83%AB%E3%83%BB%E3%83%AC%E3%8 2%AC%E3%82%B7%E3%82%A3), which is more in line with what I remembered. No year on that, but it's an AVCS model so it can't be very old...
http://forums.nasioc.com/forums/showthread.php?t=365728&highlight=ej20-r

Gen goes back to 99 w/ avcs and variable intake.

http://i51.photobucket.com/albums/f353/west_minist/2000%20Subaru%20Impreza%20SRX/HPIM1162.jpg

http://i51.photobucket.com/albums/f353/west_minist/2000%20Subaru%20Impreza%20SRX/HPIM1144.jpg

http://i51.photobucket.com/albums/f353/west_minist/2000%20Subaru%20Impreza%20SRX/HPIM1143.jpg

http://i51.photobucket.com/albums/f353/west_minist/Logs/AVCSAnalysis-1.jpg

http://i51.photobucket.com/albums/f353/west_minist/Logs/Dyno-MY00SubaruImprezaSRXAuto.png

http://i51.photobucket.com/albums/f353/west_minist/Logs/Dyno-New2nhalfresonator.jpg

http://i51.photobucket.com/albums/f353/west_minist/Logs/Dyno2-MY00SubaruImprezaSRXAuto.png

http://i51.photobucket.com/albums/f353/west_minist/Logs/GTechPro-20050420-SemiStock-rpm.png

The new EJ204 does seem not to have variable intake.
http://i51.photobucket.com/albums/f353/west_minist/MY06%20EJ204/IntakeManifoldview.jpg

http://i51.photobucket.com/albums/f353/west_minist/MY06%20EJ204/EngineView.jpg

Here is a pic with just the Turbo muffler on. Its the green line.

The car was running very rich from 3-4K

After that, the 2.5" internal resonator from Magnaflow (14") long was replaced with a 2.25" pipe.

http://i51.photobucket.com/albums/f353/west_minist/Logs/Dyno-HKSCarbonTITurboMuffler.png

Jay, I assume this rev limit raising is the overclocking your referred to in another thread? Interesting (and tempting) stuff...

PatYes. I've seen the ads every month for years just kinda blowing it off. It's a good deal for those who have to keep (cough) stock ECUs. I figured why not try it on a spare.....The only drawback is that the timing curve gets spread out over the new larger window. It may nat be as aggressive at lower rpms but it will eventually reach full advance, just at a higher real time rpm.
For a 6000 rpm limit ECU:
+10%= 6600
+15%= 6900
+20%= 7200
+25%= 7500

For a 6500 rpm limit ECU:
+10%= 7150
+15%= 7475
+20%= 7800
+25%= 8125

Jay Storm

Question, how do you get access to the ecu in the first place?

Is it a reflash?

Question, how do you get access to the ecu in the first place?

Is it a reflash?No, it's open heart surgery. Physically desolder the clockchip and replace with a different resonance value. There are other ways to do this as well. This way is just one of them (and the one we had discussed prior to me shipping off the ECU).

Jay Storm

That would mean that the car sould run more ign before in lower maps?

That could also mean that the rpm meter could be off scale?

Hmm.. interesting stuff, oh wait I already subscribed :D Is the "clock chip" you are referring to kinda like the flat metal can cap I am looking at in my old 280zx computer? I guess I'll look inside the jdm 1.8 ecu I just "won". It supposedly has a 6500rpm rev limit which is 500 more than I have now at least. At least I'll have my stock one to send off if I need more than that. :)

I have a spare '02 ecu lying around...does this really work storm? I've been dying for a 7250 or so since i got my spicy cams, springs and retainers....

West_minist: With the timing advance curve spread out, lower rpms will be slightly lower on the timing curve but higher rpms will still be at the top of the curve.

Our tach is still reading correctly. I believe it comes before the ECU on the signal line. Our aftermarket telltale light also triggers at the correct value.

2slofouru: The clockchip on our ECU was a black carbon cylinder. I'd have to see a pic of your board to try and locate it. Email it to me.

Staticfritz: The newer ECUs use multiple clockchips and would have to be carefully checked to see which one(s) would need to be changed. Your best bet would be to contact the number I posted earlier in the thread. Keith seems to know quite a bit on the subject....afterall, he's the one R&Ding this stuff.

I'll either open the one in my car tomorrow and take a pic or wait a couple of days until the "jdm" one comes in the mail. Hmm, can't wait now to open the ecu and look around, I might be able to make a little sense of it if you point me towards the right part. You think it's a capacitor, a crystal, a resistor or maybe some type of diode?

Yes. I've seen the ads every month for years just kinda blowing it off. It's a good deal for those who have to keep (cough) stock ECUs. I figured why not try it on a spare.....The only drawback is that the timing curve gets spread out over the new larger window. It may nat be as aggressive at lower rpms but it will eventually reach full advance, just at a higher real time rpm.
I've got a spare ECU, too, maybe I should give it a shot. And the reduced timing low in the rev range would actually be good for me, singing as my car pulls timing like crazy anyway. :rolleyes:

Pat

I've got a spare ECU, too, maybe I should give it a shot. And the reduced timing low in the rev range would actually be good for me, singing as my car pulls timing like crazy anyway. :rolleyes:


PatGo for it Pat! For us...it was $100 well spent! If your timing is being pulled anyway....it'd be a double bonus. You could make more use of the cams too!!!

I'll either open the one in my car tomorrow and take a pic or wait a couple of days until the "jdm" one comes in the mail. Hmm, can't wait now to open the ecu and look around, I might be able to make a little sense of it if you point me towards the right part. You think it's a capacitor, a crystal, a resistor or maybe some type of diode? It's a crystal. The ECU uses it as a time reference for these type of functions.

Jay Storm

exxxxcellent... (rubs hands together) I will have to check the one in my car in the morning, can't wait for the one in the mail. Time to sleeep now..

Storm "you've got mail"

Storm, I tried for unlimited revs and it didn't work (imagine a long row of smileys here, my computer is so slow)

I wouldnt ever use a JDM ecu, becuase of the fuel difference. If it hasnt been already stated, they use close to 98 oct fuel, and the ECUs are tuned for that.

I'm not sure if it's really "jdm" but the guy who sold it to me said it was. He also stated the car it came out of revved to 6500, now I'm wondering about that. I don't notice any detonation or power difference but I'm putting the usdm one back in soon just in case.

I wouldnt ever use a JDM ecu, becuase of the fuel difference. If it hasnt been already stated, they use close to 98 oct fuel, and the ECUs are tuned for that.So the timing will be more agressive...big deal. If you have knock detection, it's a non-issue.

fwiw...I'm not noticing any timing issues with the crystal being modded. Still have to log the tables (if our OBDII port even works) and swap to the stock ECU to compare.

Jay Storm

So the timing will be more agressive...big deal. If you have knock detection, it's a non-issue.

fwiw...I'm not noticing any timing issues with the crystal being modded. Still have to log the tables (if our OBDII port even works) and swap to the stock ECU to compare.

Jay Storm
Im guessing you use a JDM ecu and were offended by my post? Look at it like this, you wouldnt put regular gas in a wrx, why would you use 93 (or 91) with an ECU setup for much higher? Its just asking for trouble if you ask me.

Nope....:rolleyes: totally wrong (again).Im guessing you use a JDM ecu and were offended by my post? Look at it like this, you wouldnt put regular gas in a wrx, why would you use 93 (or 91) with an ECU setup for much higher? Its just asking for trouble if you ask me.All that crap means is that it is CAPABLE of advancing the timing further to take advantage of the higher octane......

I was just stating my opinion but thanks for being an ******* about it

I've ran 93oct, 91oct hell 90 oct on my JDM v7 ECU and flogged the hell out of the car too. The ecu has knock correction and timeing advance to take advantage of good gas, it also can protect the car running on lesser octaine.

Storm, you know better the to let the uninformed or inexperenced get in your way :)

Shame on me :oops

Hmm.. my old zxturbo didn't have a rev limit.. well maybe it was higher than the tach would register anyways. I wonder what would happen if I used the crystal from one of my extra z ecus?

Have the frequency measured on both. If it's higher....go for it.

Well I asked "how to find out if an ecu is jdm or usdm" and someone replied that the case won't bolt into a usdm car because it came out of a rhd car. If that is the case, I got jipped. :mad: Well, at least I didn't pay much for the ecu so I have a spare to play with. Soooo, anyone have a spare jdm n/a ecu that revs higher than 6k lying around? :o If I ever find one, I'll just swap the case so it will bolt in.

USDM 2.5 DOHC ECU will rev to 6500..

USDM 2.5 DOHC ECU will rev to 6500..

That would be nice if my car was OBD2, mine is a 95, so no 96 up ecu will be going in any time soon. I will have to just mod my ecu somehow, I guess. :confused:Funny thing is, I have a usdm dohc engine running on my 1.8 sohc ecu.