When I got my j-spec ecu, N374 ECU it had a little black box on it, I asked what it was before and I didnt have pics the I saw it on ebay. so look at image #4.
http://cgi.ebay.com/ebaymotors/ws/eB...tem=2453780001

 

Interesting, can it have something to do with the speedlimiter that JDM cars have? Just guessing here. Sorry, but it will keep the thread alive!

 

yah, I got one from my j-spec ecu too. don't know what that little black box is for.

 

Anybody wanna open up their ECU and take some pictures?<br>
<Br>
That would give a little bit more to go on.

 

Whats the benefits of a Jspec ECU?

NA or Turbo?

 

well there were no japanese rx-7 fc's that were n/a so there were ALL TURBO, but there is no real benefit for switching to a j-spec ecu other than the fact that they are available in abundance!

 

No, the speed limiter is part of the ECU's firmware, not an external module.
None.

 

Well then what is this black box then?

There are obviously differences between the ECUs, so no one is gong to take that answer seriously unless you can back it up.

In order to make a rational decision about the possible benefits of a different ECU, one needs to know what the differences are.

If you don't know what all the differences are, then you can't (shouldn't) authoritatively state that there is no possible advantage.

 

I have pictures of the little box opened, I dont know what good it will do if no one has any clue what it does, I can post em if someone wants me to.

It is in the ECU but cant you defeat it by removing a screw off the back of the gauge cluster?

I also thought that the j-spec ecu had differences in the emissions control?

 

Please do. If possible, post a close up of the components inside the black box, and of the inside of the ECU itself (to see where the connection points are).

Your shift light is controlled by the ECU, but you can defeat it by removing a light bulb

This is probably true.

 

ill see if the pics are clear, if not ill get them later this week when im near my car

 

I have absolutely no idea and never implied I did. I'm as curious as anyone to find out what it is.

Before you vent at me, you should consider the question asked, which was "what are the benefits of a J-spec ECU?" There are quite a few differences between US and J-spec ECU's, but there are no advantages to using it since the engines are basically identical in operation. Some have suggested the Japanese ECU's have more aggressive tuning to suit their higher-octane fuel, but I do not believe this is the case for cars of this age. Jap-import FC's and other Jap-import 80's turbo cars run without any problems on NZ's lower-octane fuel.

The differences between the ECU's are from the different equipment connected to it. Only US cars have AWS valves, EGR valves, shift-up lights and port air solenoid valves; only Japanese cars have speed limiters. It's quite possible the ECU's are physically identical, and only the firmware related to this equipment is different.

the ECU receives a speed signal from the speedo. Removing the screw disables the signal, hence disabling the speed limiter.

BTW, just because that box is attached to the ECU doesn't mean its part of it or has some effect on its operation. It's obviously a factory piece, but it could be for anything.

 

I pretty much agree with all of this, except that: because the two ECUs probably use different maps, for some people, the maps may work better. I realize the difference probably isn't huge.

I know people can get into this "JDM" hysteria, where they simply must have "overnight parts from japan." But I'm curious to see if there could be some real benefit.

 

But how do you know they're different? How different? Why would they be different? They could result in worse performance for all we know. I agree that solid info would be good, but anecdotal evidence suggests there is no advantage to using one. Perhaps xfeastonarsex could do some before and after dyno or acceleration testing for us?

 

I got the jdm ecu and harness not because it is jdm, i mean come one, no one will ever see it..., but rather because it came with my j-spec engine, which I got because it was easier and cheaper to get a jdm one than look for a us spec one of equal condition. My LSD is j-spec again because I got it for 35bucks... I dont know if this is what you ment... so nevermind if it wasnt...

 

I can probally do something like this if someone lens me an s-spec TII ecu. I dont know if the engine being j-spec is going to make and difference or not... I seem to forget what I learn on this forum

 

pic
ok this is getting to be a PITA, uploaded image, then it said it didnt upload, try to edit, nothing happens... please excuse the mess below....

 

here is another

 

sorry about the fuzziness, crappy lighting. i can take some better ones this weekend if needed
ok this isnt working I keep getting:
The proxy server received an invalid response from an upstream server.
The proxy server could not handle the request POST /newreply.php.

 

Hmm...that box definately looks like it does something,
are those wires connected to the ECU, or to somewhere else in the car?

 

Looks like some sort of warning driver or high current trigger.

 

you got the RX7 DSM, hehe

 

when I got it it was just a cut wire and connector, still plugged into it. This is why I was thinking it was part of the body or not directly connected to the ECU.

 

I dont get it ...

 

... mitsubishi... dsm... mitsubishi..in..the...

forget it hommie

-Carlos