Management Systems

Daniel · Post by **Daniel** » Wed Sep 20, 2006 1:51 pm

mine looks like this. Its really easy changing the rev limiter and AFM airflow measurement. Removing the boost cut looks easy aswel. Fuel maps however seem a little more tricky

Toby · Post by **Toby** » Wed Sep 20, 2006 1:54 pm

Daniel, please e-mail your rom editor! Or we can meet up and discuss and see how the two compare?

Toby · Post by **Toby** » Wed Sep 20, 2006 2:51 pm

Sheeeyaazz! ROMs and lots of info on these forums:

http://www.tangentrix.com/forums/index.php

And yet more CA18DET stuff:

http://ca18det.escic.com/files.php?cat=3

Oooh, another ROM editor:
http://nscw.kolhoos.ee/ecuedit

ChemCool · Post by **ChemCool** » Wed Sep 20, 2006 3:14 pm

You know Derek, all they say is that they are one level better than you and me. Shit Toby, I cant even get on par with a PIC,and now you start with this Proms and Prams and highlevel technical issues. Ok , so we will watch you and waiting the results.

ChemCool · Post by **ChemCool** » Wed Sep 20, 2006 3:16 pm

Toby and Daniel, in simple Afrikaans:"Ons ander ouens is rekenaar gestrem".

ChemCool · Post by **ChemCool** » Wed Sep 20, 2006 3:23 pm

Onother idea, Derek, WooHaa and me, we will serve Daniel and Toby with beers and coffee. May be our chips will then be addressed too.

Toby · Post by **Toby** » Wed Sep 20, 2006 3:27 pm

Sorry for the technical stuff guys, but this stuff really interests me! Of course, I am scared of blowing up my ECU (which might be a good excuse to get an aftermarket one

) but I must say that after Chip Logic (*spit*

) remapped my ECU, the car is much more driveable and I get more torque low down in the revs! I wish I knew what size injectors they put in, 'cos then I could modify my map for any other injector.

Freddie - the PIC story, yes I am still keen on it and want to get back to getting that going too! Electronics stuff - bring it on! Spanners and stuff, I can't do

Draco · Post by **Draco** » Wed Sep 20, 2006 3:29 pm

You can say that again Freddy, Eproms ECU EEEEE-lost thats what I am.

Bring me a nissan sx and i'll EEEE-drive it!!!!

I like electronics aswell, it dosn't mean I am EEE-qualified
from the EEE=Looser

Jay_boy · Post by **Jay_boy** » Wed Sep 20, 2006 3:52 pm

You know what, i know a fair share of some teck stuff but Gees you guyes lost me there!! im more into the spanners and tuning the mechanick`s side of stuff!! like porting the head and fitting new stuff!!

widowmaker · Post by **widowmaker** » Wed Sep 20, 2006 4:14 pm

isn't that exactly why were a club? not to suffer alone in silence, but to swop knowledge. You can't all be perfect (like me).

I will let you know when I find some of that knowledge stuff

hehehe

Jay_boy · Post by **Jay_boy** » Wed Sep 20, 2006 4:18 pm

The only problem is that that tree of knolage does exactly the opposite

LOL

Toby · Post by **Toby** » Thu Sep 21, 2006 7:13 am

Here's a simple explaination of ROM's and ROM editors and what they do:

- As you know, the engine contains many sensors all hooked up to the ECU (engine control unit). The ECU is basically a microcomputer.
- With electronic fuel injection, the ECU needs to tell the injectors when to fire, and for how long. It also needs to tell the coils when to fire the spark plug.
- The ECU does this by using a lookup table that says something like: at 500rpm, under ideal conditions, open injector for 10 milliseconds per cycle. At 3000rpm under ideal conditions, open injector for 50ms. etc, etc, etc
- This lookup table is pre-programmed into a memory chip called an EPROM (erasable programmable read-only memory), by Nissan.
- The ECU will adjust values in the lookup table depending on non-ideal conditions (for example detonation or engine too cold or air flow too low, etc.)
- The lookup table is thus important to the power delivery of the car. It can be changed for more fuel efficiency, or more power, or even both. Nissan obviously tuned it as best they can for Japanese conditions (including high octane fuel).
- The ROM editor allows you to read the contents of the memory chip, and then change the lookup table (and other things) to suit what you want. Thus, you can get more torque in the low rev range by adjusting the fuelling and ignition timing in the lower rpm, without affecting the top end, etc.
- Once you have edited the memory contents, you can then program that back into another memory chip, and replace the standard one with the new one.
- In addition to the fuelling maps (lookup table for injector), there is an ignition map (lookup table for spark plug firing) as well as a map of how the air flow meter works (so if you swop AFM, you must update this map in the ROM), and there are also rev limiters, speed limiters, etc.
- The cool thing is that you could put more than one map onto a chip, and then use a switch to switch between different maps. For example, you could make a map with a speed limit of 100km/h and rev limit of 5000rpm, and use that when you leave the car at a garage or lend the carf to a friend

This kind of setup requires the building of a daughter-board though, so it's not that easy.

Hope that sheds some light on the subject. As you can see, there's lots of potential here for free power! It must be noted tho, that ROM editing is not an art - it requires lots of technical understanding of the combustion process, as well as a dyno to test your changes to make sure you're getting what you want out of the tuning process. Most of the tuning shops do this by trial-and-error.

Daniel · Post by **Daniel** » Thu Sep 21, 2006 8:17 am

well said toby.

Unfortunately the old arse dyno doesnt cut it.
this may be of interest to someone

A home dyno kit

Draco · Post by **Draco** » Thu Sep 21, 2006 8:17 am

Thanks for the explanation, so when are you building a daughter board, mother board or sister bourd for me, tested by you?