kuhlrx7

Ok I know you are sopost to be able to run it in place of the n333. but is it just plug and play? what functions does it have? fuel cut? timing for boost? any limiters? whats the differances? is there map differances to the n333 or n332? Is it just a rebaged n333 with extra or differant chips or programing? any jumpers to set or does it just sence its in a turbo by being pluged in? anybody have a n338 they can open and post pics of for comparison?

Icemark

N338 is the same as a N333 when used on a Turbo motor. It has internal sensing that switches instruction set based on the inputs.

kuhlrx7

what about fuel cut or a limiter is that the same? and what about the inside set up of the computer? could you use a chip change like the rtec7 for fuel cut or would you need an fcd if the n338 has fuel cut?

If some one had a n338 they could post pics of the inside that would be great.
can you do that mark? I saw on a search you where runing a n338 a while back.

Icemark

The N338 uses a different set up than either a turbo or non-turbo ECU, and most aftermarket chips are not set up to deal with the odd inputs/outputs.

I have a couple N338 ECUs what are you looking for on it??

kuhlrx7

does it have the same fuel cut that the n333 does? and as for the insides of it , I was wondering about the eproms layout and jumper locations is it more like a s5 than a s4 ecu?. I am considering one to use for my car and want to know fact from fiction. example some say it has better maps than the n332 or n333. some say it has no fuel cut or is set at a higher level, some say it has a speed limiter set at 115, some people say the reverse of those above

Icemark

No map difference than a N333 in Turbo set up or a N327 in a non turbo set up.

Internally it is like a S4 Turbo ECU.

Same fuel cut in Turbo mode as a Turbo

And the 115 MPH limit is bogus... no North American ECU has that. No North American ECU has a speed input or a output on the speedo for it.

Here is a slightly modified one:

ERAUMAZDA

errr. is this the vert ecu we talkin about?

Icemark

yeah... 88 vert

ERAUMAZDA

So can u answer this question? how does the ecu know when its suppsoe to use what map. Don't the convertible and turbo use different injector sizes?

Icemark

I haven't backwards engineered it yet enough to know for sure, but I suspect it is related to boost/pressure sensor input.

The weird thing is the pin R circuit input. It boosts the RPM when the power steering inputs ground, but retards timing when the knock sensor inputs ground on the same input.

ERAUMAZDA

I heard for a while that the vert ecu has a turbo map...but I always wonder what determined if it was turbo or not. Ultimately, if you were to boost the injector staging would be would either primary 440cc injector map to 550 secondary map or 550ccc injectors map to a 550 injector map.

ERAUMAZDA

Maybe the AFM allows for that or possibly because the vert weights more the same mapping used for 550cc injectors is used in the vert due to high loads. Shiz man.

kuhlrx7

ok, I tryed to save your pic to open it up in gimp. this way I could lighten and blow it up in size so I could see it better, but was not able to. so whats been modified in your pic? is pin r the ony werid input? this may sound strange but was the n338 a us or n america only ecu? trying to ? why the dual use for this computer sence mazda could have used one they already had such as the n338 for turbo or n327 for na use in the convertable if it was a n america only ecu. unless the maps were differant because of the weight of the car or something else? the eprom location looks the same are the the same as the ones in the n333? if so one of the pin in puts must be the switch for it to change modes between turbo and non turbo.

jon88se

icemark, so do you think those of us w/ vert ECU's and TII motor can send our ECU's out to rtec7 for the chip?

ERAUMAZDA

Good question. I don't see why not?

Icemark

It has been my experience that most aftermarket Turbo chips do not work in the N338 in a non turbo application.

The chip I currently working with is custom chip by a guy that is planning to do a Rtec type thing. He does not have then for retail yet.

Icemark

The picture is considerablly reduced both in size and quality for posting here. The ECU in the picture is not instock form, and has been modifed for inputs and outputs (notice the couple of big resistors on the connector board) as well as has sockets for the fuel and timing chips.

Yes the N338 was a north america only ECU.

I do not have it confirmed but I have been told by a couple of people that know persons that worked at MNA when the vert was released, and the scoop was that Mazda was planning on bringing both the Turbo and Non turbo 'verts to america.

Because the cost certification was so substantial and the production of the vert was so low, it was cheaper to use a single ECU and just plug in the motor based on drive train setup. Of course we never got the Turbo vert. Mazda ran into issues in 87/88 because of the weight of the Turbo version would have put the car into gas guzzler territory (something that the Japanese government as well as Mazda higher ups would not allow) as well as it would have pushed the vert into the near $30K cost territory.

kuhlrx7

so in a turbo application the chips work?

kuhlrx7

I see the resistors I cant make out the sockets though. did it have the same eprom chips as the n333 before mod?

Icemark

no, the 88 vert chips are dedicated for the vert... they do not use N333 or N332 chips