City T2 ECU Reverse Engineering Mk2

[bmgjet]

Hey any one got the rom dumps from any of these.
Also if you know any of the hex locations for stuff that would be useful as well as it would save me some time.

If your intrested in when I want them iv recently been adding support for nissan roms via a plugin for crome. Could do the same with the city maps if I can find time.

I could always pull the map from my T2 but thought id ask first.
Thanks.

[James]

Read the stuff I have here:

viewtopic.php?t=2909&postdays=0&postorder=asc&start=45

and here:

viewtopic.php?t=3077

Join my Google Code project for reverse engineering the City T2 ECU code:

http://code.google.com/p/ecureverse/

It also has T1 and T2 HEX Rom dumps in the downloads section. Make sure you check out the latest version of the commented T2 code, I've made quite a bit of progress in there, commented a few thousand lines.

[bmgjet]

Thanks

[bmgjet]

Made a start on the plugin and managed to get fuel cut changer working but if anyone has locations of whats what in the .bin files that would be helpful.

Such as 0X32A8 is the byte where the fuel cut is.

Looking for location of the revlimit and speed cut if it has one.
Also revscale, mapscale and location of fuel map would help but iv got a few idea's where these are but need to figure out the maths for converting them.

[James]

It has no rev-limit or speed cut.

If you check out the infobase I think I have the maths for the Rev scale, but I can't remember where it is.

If I recall correctly in the old Honda literature it mentions something about the T2 ECU using 5 different maps, and when I have looked at the files it looks like there is 5 separate maps in there. I was planning on using an Ostrich Romulator I have here to track the map values that are visited when I got my car going again, so I could work out what it was doing.

Keep us updated with the progress, its awesome to have someone else working on this finally!

[bmgjet]

Hmm wonder what the 5th one would be for. I was only expecting there to be 4.

1 for map sensor 1
1 for map sensor 2
1 for map sensor 3
1 for safe mode.

This will make me have to re-think how im going to display it in crome.
Was going to use the high and low ignitions pages to display fuel map 1 and 2. then high and low fuel to display fual map 3 and 4.

Been reading through the commented code.

[James]

Cool, there is only 2 map sensors, A and B. I wondered if the other maps had something to do with a coolant temp correction and maybe and air temp correction or something. I thought maybe because they had limited processing (only 6Mhz) they put those corrections in lookup tables instead of using equations, but they would probably only need to be 2d tables eh...

[bmgjet]

Plugin so far.
http://bmgjet.com/city-t2-crome-support-0.0.1.zip

Fuel maps seem to be maps used by mapsensor A.
Ignition maps seem to be the ones used by mapsensor B.

How to install.
Copy to Crome Dir
Install as normal plugin.

Dont expect anything to work. The only thing iv tested in the fuel cut/boost control.

[Charles]

Don't think you'll find any ignition maps on there. It is controlled by the old weights and springs in th dizzy and the vacuum advance.

Back in the day I thought they were there to allow the seamless changeover between vacuum and boost. I have tried a JDM civic (na) ecu from 1986 and it runs the car happily until it comes onto boost - then it craps itself. Pretty sure one is reponsible for vacuum and one for boost and both read around the crossover. Don't really know.

I will be interested in the maps again now I have my old car back, need to tune for the GT17. The minis (with the crappy A series motors) are getting between 200-250bhp at the wheels at 21psi WITH A CARB! Promising for a 200hp aim.

I have had 200hp with a Garret T2 @24psi before but low down it was a dog.

[James]

Wow Charles great to see you back here!! Which is your old car? I guess you must be back in Aus now.

[Charles]

This one below. It was still in the shed amazingly. It took about 30mins of mucking about to get it running but it is now in a thousand pieces. It ran well with the 3 year old fuel but the whipper snipper didn't like it.


I have rebuilt the suspension and set them on the firmest I can which means it will probably be a bit stiff. I have removed the bumbers and installed some alloy blocks in their place, changed the fuel system for about the 100th time, put a smaller diameter pump with better damping (I hate noisey pumps) and fiddled with all the fittings to ensure no restrictions or leaks.

I have fitted a light weight gel battery in the wheel well, replaced the clutch with a heavier duty number, replaced the brake lines and now I just need to spend some time on the body.




http://cityturbo.com/forums/viewtopic.p ... sc&start=0

[James]

Great to hear that car is getting another lease of life.

Colza and I recently pulled an old Prince Skyline apart that had 20+ year old leaded fuel in it, the lawnmower didn't like that either.

Is that suspension Koni Reds? The wet inserts for the 75 by any chance?

[Charles]

Yep - kind of off topic but koni red wet inserts shortened and fitted into shortened non openable shock casings - set on stiffest setting (may need to drop it back as the rebound is so stiff compared to the brand new pedders gas I have - I am worried about shock jacking).

[bmgjet]

Continuation of this plugin for crome has stopped since the crome scripting api isnt flexable enough.

Have started again using tunerpro since it has a lot more flexibility.

On another note does any one have a ECU they would be willing to donate or sell for cheap so I can plug my ostrich into and use the hex tracing to see what parts are being access.


----
James how did you find the conversion for the RPM table.
Iv found the hex locations of them and know that youv written that they should be

500 600 700 800 999 1200 1399 1600 1999 2401 2799 3200 3599 3998 5000 5990

But the formula

(1 / ( Value x (1 / 62500))) x 30
doesnt give the correct values

[bmgjet]

Bought another Ostrich so that I can do the nissans that need 2 chips at work. But will also have the bonus of being able to take it home with me while the work ones still at work.

Guess im just going to have to open up my T2 ecu to socket it and see what parts of the code are being accessed at what conditions.





So im expecting to make some development over the week/weekend.