Tomei Rytec & Nistune

[oneten]

Hi All,

Just found something interesting the other day when installing a Type 4 board into an S15 ECU, thought I would ask here about it.

The fella I was doing this job for already had a Tomei Rytec ECU in his car, which had been problematic & kept dropping its tune - hence him getting rid of it for a Nistune. I had never seen a Rytec before (or heard much about them for that matter), for some reason I thought it a piggyback style computer similar to the Emanage. When I pulled it out, I was suprised to see it looked exactly like a stock ECU with a custome TOMEI top cover plate. A quick disasseble of the case showed it was indeed an original Nissan S15 ECU, but was carrying a daughterboard VERY similar to the Nistune board. Furter inspection showed it works in virtually the same way as the Nistune, same ribbon connector, even the same jumper was changed on the board. The Rytec daughterboard had very similar componentry (not that im an expert) but what looks to me like dual NVRAM (odd & even im guessing) and a couple of matching processors or multiplexers (again guessing), and there did not appear to be any further changes or additions to the stock ECU board. The Rytec also uses the consult port for tuning.

Now what had me intruiged was that this paticular Rytec was setup to use MAP load sensing, instead of AFM and also had an Intake Air Temp sensor hooked up. These 2 sensors both spliced into the factory AFM harness, there were no additional wiring additions to the stock Loom.

I had it in my head that the associated hardware inside the ECU for driving/interpreting the signals from a MAP sensor as opposed to a AFM would need changing to allow this to work - or even some wiring changes, but apparantly not...

So what im wondering is is this possible on the Nistune board as well? Or have i missed something here?
I would love to be able to ditch the stinkin AFM and run a tidy MAP sensor.
I think this would increase popularity a fair bit also as most the blokes I do Nistune install for in W.A. say the AFM restriction is the biggest downer to them.

Cheers,
Hayden

[Matt]

Okay you've got my interest. I want to know more!

http://www.skylinesaustralia.com/forums ... -software/

http://www.tomei-p.co.jp/_2003web-catal ... nroad.html

They dont seem that easily available and are quite expensive compared to Nistune. Looks like they came up with the NVRAM idea before we did then. If I am able to get a copy of the ROM out of the board then we are in business. I could 'look' at the MAP conversion code and put something similar inside Nistune. Interest also where IAT hooks up

[oneten]

Hey Matt,

Awesome to hear a positive response! You got me excitied now.
What I can do is get in touch with this guy I did the install for, and see if he will part with the S15 reytec & sensors he had in his S15, could probs get it cheaply enough, and send on to you for further inspection if you like?

As far as i know the Reytec was still operational, was just having trouble keeping the tune on board and was either reverting to factory tune or Limp home mode.

Should still be able to pull the image off the board.
As for the sensors, I would have to have another look at how it was hooked up but the MAP Sensor & IAT sensor both spliced back into the AFM harness somehow, now I think about it, the S15 AFM has only 3 wires, 1 Ground, 1 +5v and 1 Sensor output wire? If thats the case not sure how they worked this without additional wiring.

Let me know if your interested and I will tee it up with him.

Cheers,
Hayden

[oneten]

Also some good info here, including online demo of the software (which is in japanese :/ )

http://www.tomei-p.co.jp/_2003web-catal ... eytec.html

EDIT: In the above link, have a look under the Tech Info button up the top of the page... has some vauge info on IAT & MAP inputs.

[Matt]

Okay will have a look. I'm keen on seeing how they put the IAT into the ECU and if they used another input

I had read about these units losing program after battery power but that was a random forum comment with no further information. If it was NVRAM (EEPROM backed and not battery backed) then this shouldnt happen but given the age of the unit I suspect battery backed solution which is susceptible to these issues

Basically I am interested. Would probably have to pull the board from the ECU and wire into an adaptor and read using modified base image programmer software (like what was done for JWT OBD-II boards)

[STATUS]

let me know how this goes, if its gonna take a while to get an answer on that one above i am keen to buy one and ship it over.

feel free to email me if your keen as i am happy to hit the go button at any time.

[Decs]

this also exites me a LOT!

i'd almost give my left nut to be able to run nistune with a map sensor!!!!

[Black pepper]

this idea is a wonderful one and if matt could pull the code nistune is #1. both in maf and map.

[Black pepper]

i think every one that has a type 4 s15 board should get together and contribute to buying this Tomei Rytec board so matt can ripe it apart. (i dont think we should allow one person to purchase the board and it will work out cheaper if everyone chip in a 2 cents )

[Matt]

Hayden - any feedback on getting hold of this? Otherwise might see if Trent from Status can source one

One of the Monk House drift cars has a GTR Rytech in it so I was able to borrow it whilst fixing another issue on the ECU and get a ROM dump out of it. I would still like the S15 unit however

The GTR unit is just an EPROM chip so I suspect the S15 would be also just standard Jap board. NVRAM like simteks has only just been recently available

Rytec was setup to use MAP load sensing, instead of AFM and also had an Intake Air Temp sensor hooked up. These 2 sensors both spliced into the factory AFM harness

In this one there is a single AFM input to the ECU which goes through a clock generator and some unknown custom device on the board. Got pics from this one but need more infomration

Guys cost is not an issue - business expense! Just sorting out where to source one for a reasonable price...

[oneten]

Hey Matt,

Sorry for the late reply! I have been insanely busy over the last few months and the leadup to chrissy with custom wiring jobs, only just starting to get onto pending NIStune work now hence my absence from the forum.

OK so do you still want the S15 Rytec? I sent that customer a few texts back when I first brought this up but never heard back from him - I dont think he was keen to give it away for free... I still have his details so can ask again, Might offer him some money for it? He also has the MAP sensor & IAT sensor that were used with his ECU so would be a good one to get hold of methinks.

Let me know,

Hayden

[oneten]

PS, If you want me to source one from Japan I can do this for you, we have a good relationship with Jesse Streeter he would be able to get me one and post it over no problemo.

[Matt]

I'm fine paying for it. Shoot me an email @ info [at] nistune.com with what he wants etc and I can sort something out

[oneten]

The Reytec has landed!



Had a quick disassemble, took some photos for my own historical purposes incase oneday I am good enough at amatuer electronics I can understand some of what makes this thing tick...



You can see this is clearly a Nissan factory S15 ECU, with the Tomei Reytec daughterboard interfacing onto the mainboard in the same fashion as the Type 4 board does.
Except for that blue wire...




This is the MAP sensor harness, as supplied by Tomei. It wires onto the 3 standard AFM wires, then goes through a small black & what I can only guess, signal conditioning box before connecting to the MAP sensor. Unfortunately, the bloke I bought these parts off wasnt able to locate the MAP sensor. He reckons its in his house someplace, and will let me know if it does.
Im going to hazard a guess that Tomei used the ever popular Denso DPS-310-2000A MAP sensor. Ive seen the same sensor on plenty of other Japanese electronics (especially Apexi), and the plug matches.



And here is the Intake Air Temp sensor. Looks like an OEM Nissan sensor.



I was able to get some info from the previous owner regarding wiring of the IAT, he says the workshop who tuned it had to run a wire from it into the loom near the ECU... See I was stumped as to where this would interface into the ECU, as the ADC channel that the AFM would normally use is being used by the MAP now, its not like Nissan just had spare pinouts handy for wiring additional sensors in... but then I downloaded the Tomei maunal for the Reytec and found it wires into Pin 26 on the ECU (26 for S14a, 57 for S14, and 26 for S13), which is the Exhaust Temp Sensor (or Cat temp sensor, for detecting high EGT's when cat is blocked IIRC) which is the most useless input on the OEM ECU therefore the easy choice!

The Tomei Reytec user manual is available via this link: http://www.tomei-p.co.jp/manuals/pdf/RE ... NGLISH.pdf

For more picture of the Reytec daughterboard in higher res, click this link: http://www.photobucket.com/tomeireytec

I may have omitted an obvious detail, its late and im tired.

Cheers,
Hayden

[oneten]

PS, you were quite right about the eproms, does that affect real time tuning at all? Im 99% sure these are real time tunable through consult... Havent read through the manual though.