Factory Ecu Re-mapping Discussion

[TSL]

Just carrying on from the Sliding Performance turbo upgrade thread....

http://www.skylinesaustralia.com/forums/in...2615&st=100

A lot of interest has been expressed in regards to re-mapping the factory ecu.

I thought i would kick it off and maybe share a few secrets with those who want to learn more.

First of all i must clarify a few things.....

The methods discussed here will relate only to R31, R32 and R34 factory ecu's.

R33 factory ecu's are notoriously difficult to remap. It can be done, there are a few methods, none of which are particularly cheap or easy to do. I may start another thread specific to R33 ecu's at a later time but as for now i don't want to clutter this thread with any R33 information.

For those who are interested in learning the basic principals behind factory ecu remapping i suggest you have a read of this.....

http://www.ztechz.net/id10.html

Although some of the information is 300zx specific, the process is largely the same for R32.

Now some software to get started.....

(Rom Editor Link coming soon......)

Lawrence Mooney's Nissan Live Edit and NRE

http://www.romeditor.com/liveedit.html

Some of the basic hardware you will need.....

Decent quality soldering iron with adjustable temp. Good solder sucker and some braid/wick.

28 pin IC sockets.

27c256, 27c512 EPROM chips. Can be purchased online from various electronics parts suppliers. Search around for the best prices.

UV EPROM eraser. These can be found quite cheaply on ebay.

EPROM programmer. I use the willem unit...... http://www.darkwire.com.au/html/eprom_pcb4_5c.html

There is also one on ebay called the TOP2004 EPROM programmer which is apparently quite a good unit also.

To be able to make changes to the maps in real-time you will need some form of rom-emulator.

The pocket romulator is available at a reasonable price and works with Live Edit. http://secure.transtronics.com/EPROM%20Emulator.html

One of the most important things is to get some form of maptracing/ecu feedback. While it is possible to achieve this with the multi-rom/NRE combination, the total cost for this setup is above and beyond that of an aftermarket computer like a power fc. For the home tuner this is not practical.

The most cost effective way to go is via OBD consult. Using an OBD interface cable and one of the various consult programs you can have full map-tracing, sensor feedback and even full data-logging with the correct software.

You can get a consult cable from.....

http://www.plmsdevelopments.com/consult_if.shtml

(software links coming soon.....)

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I would like to provide software, address files and maps..... If somebody is kind enough to provide some web hosting!

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I will update this as time allows.

Cheers -Jeff

Edited November 19, 2006 by TSL

[Andi]

I was aware that R33 were not remappable but I was under the impression it was the same for the R34 due to the same engine? So its actually possible to remap the R34 GTT ECU?

If so, this is good as I always wanted to go the remap route to keep the standard cold start, AC etc. functions but thought it wasn't possible for my R34, and since the PFC's are no longer being made this might prove to be the perfect solution if I decide to upgrade to a new turbo.

From what I understand the traditional rom tuning method was to 'burn' and image to the rom chips and do a dyno run, then to take the chip out to burn the new necessary adjustments correct? But I'm pretty I read somewhere that someone has made real-time remapping possible? Could this be done on the R34 as well?

[paulr33]

yeah the er34 is remappable, and the r33 one is as well, but you need to run a different chip, which means more $$$ so its not worth it. by why re-invent the wheel when 5 other companies have already done it? there are plently of good ecu's out there for you to use, including many many 2nd hand pfc's

[TSL]

To do the R34 ecu you need to install a daughterboard, similar to the way the sr20 ecu's are done. It's a slight extra cost compared to the ease of doing an R32 ecu, but in reality its only about $250 all up to purchase the daughterboard and have it professionaly installed. Once you have done this modification you can the reprogram the R34 ecu using common 27c512 EPROM chips. All for less than the cost of a basic interceptor ie. apexi safc.

One way around the R33 issue is to use a Z32 ecu.....

Edited November 19, 2006 by TSL

[paulr33]

well there u go

[MerlinTheHapyPig]

IMO, there aren't enough tuners out there who can do remaps, a few points to consider:

-The tune is only as good as the tuner, remaps can do almost everything most aftermarket ecu's can do. The tunes can be equally as good. Tuner skill is more important than the actual ecu choice.

-The tuner needs the correct equipment to produce a good tune, as a minimum they should have an EPROM emulator which supports map tracing (via NRE software typically), and something which provides a knock indication (microphone or sensor). (this is in addition to the usual tuning tools - dyno, o2 etc.)

-Most Nissans can be remapped (some such as r33 require a plug-in board)

-Remaps can't provide any data logging or hand controller display readout (this can be achieved using consult cable and laptop)

-buying the equipment and road tuning it yourself is more expensive than an aftermarket ecu + tuning, and the tune will usually be poorer. It's also more of a hassel to do the tuning, most will find powerfc tuning easier, and you have the ability to use the hand controller to make adjustments on the road.

-if you can find an established remap tuner who you trust, then it will be far cheaper than an aftermarket ecu! But, if you aren't happy with the tune or tuner, then there are not many alternatives

-On Nissans, remaps are a very good option for automatics, as they retain the transmission timing retard logic - a feature no aftermarket ecu has managed to copy properly. Powerfc's will usually blow up an auto trans after 6 months or so......... Best solution here is usually to buy a manual!!!!

Edited November 19, 2006 by MerlinTheHapyPig

[TSL]

Post i responded to has since been deleted......

Edited November 21, 2006 by TSL

[CEF11E]

Nice one TSL.

The Gear I have is a Willem PCB4.5 burner and came from darkwire aswell. really good simple programmer that does all 27 series eproms as well as EEproms (electronicaly eraseble)

you can get a UV toothbrush sterilizer from Jaycar and is now only $10!!!

part number is CAT. NO. GH1507 you will need to mod it to take a power supply. I used a 9V DC adapter to power it. It has a timer that can be over rided but I just use it 4 times and it wipes the memory of any chip after that time.

I buy my eproms from www.futurelec.com.au. They are about $3 each. I use 27C256 in 60ns. (don't use slower than 90ns as the ECU needs chips atleast this fast.

I have not gotten round to getting an emulator or consult interface but will shortly.

Software I use

Live edit

hex editor

romscan

sometimes rom editor

Live edit is good because it will recalculate injector size for you and rescale all the boost tables at the same time not just change the K value. Also has an easy to use interface and in not in ENGRISH like rom editor.

What order do you do things in when you are tuning TSL?

The way I have been doing things is as follows:

start with factory map,

Change TP limit to 254 all across

Change speed limit and rev limit if desired

Recallibrate to new VQ table if needed

Change injector size if needed K value, lag time and (ignition and fuel scale)

write this to chip and put in ECU, test for idle quality and running. dyno the car (nissan ecu allways runs 10:1 or close to with RB20DET map)

Analize printout and compare to tune AF display. adjust fuel map for desired ratio (usually 12:1) burn chip and re dyno car to confirm AFR's.

once AFR's are 12:1 work on timing map increase 1 degree at a time till peak torque is reached (making sure there is no pinging) no need for any more timing once peak torque is reached.

depending on driver richen up area of the map that is used on full throttle changes from gear to gear takeup, (usually 4400 rpm if changing at redline) also back off timing on the corresponding 4 map points by 1 degree this reduces the chance of pingng on hard changes.

road test the car because a car will quite often ping on the road that would not on the dyno.

Please don't take my methods as gospel I am not a mechanic or a computer programmer. This is just how I have tuned ECU's and have found this method to work for me.

How do you guys do it?

[RedDrifter]

Thanx for starting the thread TSL.

The stock ecu is a wonderfull thing in the R32 GTS-T and GTR.

I have been messing with mine for well over two years now, learned alot and made a few f ups but hey thats best part of it. Oh and yes if you get it wrong you can kill you motor. I put in a overadvanced ignition map in on my old sick motors ecu and it finnished it off good. But live and learn.

When I fisrt started I new bugger all about it to be honest.

The stock ecu maps as shown in the ztech web site allow the tunner to tune to base afr's and I can tell you this make tunning the ecu a whole lot easier. If done correctly you can get the ecu to run bigger injectors ad a z32 afm and retain all the standrd functions and in most cases hold near stock fuel economy.

Out of curiosity how many people here done this now ? And did you find any floors or myths about tunning the ecu?

[CEF11E]

I have done around 30 cars and have had good results with all. I have been doing it for around 2 years aswell and have learned from scratch and trial and error as there is very little information out there.

it seems to be a bit of an unspoken black art. I have spoken to people that don't want to talk about it to protect the little secret they have been hiding. I see it as a service just like getting a power fc tuned. anyone can offer it but anyone can also do a really bad job.

Also, for the non beleivers, have a look at how many load points there are in the stock ECU and than look at how quickly it accesses those. also the maps can be expanded. the stock ECU is a good thing. Marketing has told people to get something that is not needed.

I have seen a 900ps GTR running the factory ECU. now why would you do that if it did not work?

[RedDrifter]

I have done around 30 cars and have had good results with all. I have been doing it for around 2 years aswell and have learned from scratch and trial and error as there is very little information out there.

it seems to be a bit of an unspoken black art. I have spoken to people that don't want to talk about it to protect the little secret they have been hiding. I see it as a service just like getting a power fc tuned. anyone can offer it but anyone can also do a really bad job.

Also, for the non beleivers, have a look at how many load points there are in the stock ECU and than look at how quickly it accesses those. also the maps can be expanded. the stock ECU is a good thing. Marketing has told people to get something that is not needed.

I have seen a 900ps GTR running the factory ECU. now why would you do that if it did not work?

30 odd cars is a good effort I would have to say. Ive only sorted 2(my car and my brother car)

I have seen somewhere on the net that there are a few 9 second zed's running stock ecu's so the 900 hp GTR running a stock ecu sounds very doable.

I have found out something that I still am unsue of but anyway I found that changing the VQ map when changing the afm from an r32 to a z32 caused some reall probs as describe on a few sites out there. When I set the K constant up correctly the car ran almost perfect afr's up top but down low the afr were way way learn. I ponded on this for weeks (about 12 months ago) and in the end I used the stock r32 VQ map and the ratio's are almost spot on across the board?????.

Now the thing I haven't tryed yet is to set it up again with the z32 VQ map and it will run lean at idle so I was thinking of uping the void constant to sort this? Unfortunately untill xmass I wont have an afr meter to use. (talked my Bro and Parents into an afr meter for xmass hehe).

Anyway if anyone is would like to know if you increase the void by one increament it tends to up the afr at idle by about 0.1 afr so then for every 10 you will increase/derease the idle mixtre will increase/decrease by 1 afr.

The K constant (as they like to call it increase/decrease the whole maps afr's across the board including idle mixture by the same increaments.

If anyone sees any probs/floors/queries with what I am saying please post as I really never had much of a chance to talk to others who have done this and those who have had alot of experience etc.

Edited November 19, 2006 by RedDrifter

[CEF11E]

Yep, I know exactly what you are talking about. What I usually do is change the VQ map after changing the injector size and then changing the first 5 scales in the fuel TP scale and RPM TP scale. I multiply the number by 1.1 dec. this will keep the AFR's CLOSE to factory up untill 3000 rpm if you are using the factory fuel map as a base and only changing it up high in the RPM range.

[fEkuaR]

Good read guys *thumbs up* very interesting

[RedDrifter]

Yep, I know exactly what you are talking about. What I usually do is change the VQ map after changing the injector size and then changing the first 5 scales in the fuel TP scale and RPM TP scale. I multiply the number by 1.1 dec. this will keep the AFR's CLOSE to factory up untill 3000 rpm if you are using the factory fuel map as a base and only changing it up high in the RPM range.

Well the first mod I did was the RX7 Injectors. After a month I then did the z32 afm and thats when I had the Probs with the VQ map and afrs down low.

Thats interesting way to sort the issue. I can see how this would work. Its nice to know I wasn't the only one who found this minor issue.

How do you find the idle once the Z32 afm is added?

I found the idle to be a little jumpy but not too bad but not quite as stable as the stock afm. I am guessing this is to do with the resolution of the afm?

Same prob was with my brothers R32 aswell and he's using GTR R34 Vspec injectors and a z32 afm.

Edited November 19, 2006 by RedDrifter

[TSL]

Ok if people are going to try this themselves then here are a few suggestions......

Prehaps most importantly of all, you need some sort of feedback/trace facilities. It is essential to know exactly what TP values you are hitting. You need to know this so you can set your TP (load) scaling correctly.

The easiest way to get this is via OBD consult.

There are several manufacturers of consult cables.....

PLMS : http://www.plmsdevelopments.com/consult_if.shtml

Blazt : http://www.blazt.biz/index.html

It's really the best $100 or so you'll ever spend. There are numerous software consult programs available, some are free or a very small cost. Some of them offer quite sophisticated datalogging. Search to find the program to suit your needs and budget.

With consult you have constant, realtime streaming of data covering almost everything you need.....

RPM (useful to log and see what map points your hitting)

MAF voltage (find how close to the limits of your maf you really are!)

Coolant Temp (useful to log)

O2 sensor voltage (good for tuning light throttle points)

Road Speed (signal from speed sensor in gearbox)

Battery Voltage

Throttle Position (signal from TPS, useful to log)

Injection Time (in ms)

Timing (current timing in degrees BTDC... is the ecu running the timing you expected?)

TP (aka load... one of the most important pieces of info)

Even if you don't have an emulator, consult feedback will save you a lot of time burning chips by allowing you to target problems more efficiently. Lets you know axactly what map points you are hitting.

You can even make overall adjustments to fuel scaling and timing in realtime via consult, although these changes are not permanent.

Needless to say you get full error display and fault readouts for all your sensors. Great for hunting down those idle issues.

More later......

[dontfeelcold]

So how good are the standard ecu's in terms of how finely they can be tuned? (ie as good or better than PFC/Autronic/Motec etc etc or worse)

Edited November 19, 2006 by dontfeelcold

[Simon-S14]

Gread reading Jeff! im learning a lot here.

[TSL]

The question that always comes up..... how fine is the tuning resolution?

Really hard to quantify as there is much more to how an ecu works other than just how many map points it has.

In short its on par with power fc, in some areas the factory ecu is better. A lot of people like the knock feedback from the power fc. Personally i like the active retard vs knock facility of the factory ecu.

Much better than cheap/old standalones like microguess etc.

Probably not fair and a little difficult to compare directly to big players like motec, autronic. Let's face it if you can afford to purchase, install and tune a motec then you are playing in a different league.

The factory ecu's (even the old R31's) have at the minimum a 16x16 point map for timing and another 16x16 map for fuel. Cars made from around 1990+ have at least 2 maps each for fuel and timing.

The load points and rpm points can be user defined to cover any scale you desire (within reason).

Example fuel map with trace.....rb20det approx 210rwkw......

The factory ecu's ability to control injectors double the standard size and maintain perfect cold start and idle when tuned correctly is remarkable.

Besides the obvious timing and fuel maps there are numerous other tables for controlling idle speed, A/C and P/S switching, decel fuel cut/recover, temp vs enrichment, accel enrichment, fuel cut (aka boost cut), max speed, max rpm, etc, etc... well you get the idea. All the things you would expect.

One of the nice things about the factory ecu is how resilient it is to problems. Bad fuel, bad sensor, etc... fault/limp mode will still do its best to get you home with your engine in one piece.

Edited November 19, 2006 by TSL

[RedDrifter]

TSL :- May I ask what software that is? I don't thinkI have seen it before.

[TSL]

How the factory ecu works.....

Lesson 1 : Fuel

It's very important to understand how the fuel tables work within the factory ecu. Hopefuly if you have read the ztech link i provided in my first post you will realise that the fuel table is broken in to 2 modes of operation. Closed-loop and Open-loop. The factory ecu method of having flags for map points where closed-loop operation is required is quite clever and flexible. It allows you to easily customise your fuel maps to suit economy for road cars. Or for a track only car you may choose to turn closed-loop off for all but the idle region of the map.

When in closed-loop the ecu uses feedback from the o2 sensor to achieve relatively precise a/f ratios around the 14.7:1 region. So when you are tuning the closed-loop part of the fuel map you can think of the values as being a form of a/f ratio target. If your injection and maf calibrations are correct then it is fairly easy to tune this part of the map.

Open-loop is a different story. Most people make the mistake of assuming the values on the fuel map can be directly related to a/f ratios. It simply does not work that way, despite some software displaying theoretical a/f based on these values. For all open-loop operation you must think of the map as purely a Volumetric Efficiency map. Now the ecu makes some calculations based on airflow readings, engine speed and throttle position etc. If it were possible to hit certain a/f ratios based purely on these calculations then it would almost make the fuel maps redundant. In the real world it does not work like this. Every different combination of engine will have different operating efficiencies at variying load and rpm points.

Proof of this is that even similar engine combinations can sometimes have wildly varying fuel maps to achieve the same target a/f ratios. The main thing is to forget what the map looks and only give the engine what it wants. If you end up with a big lumpy map to get linear a/f then so be it. If your engine needs a big lump of fuel correction in the mid range but fuel taken out top, do it. If your map ends up completely flat with seemingly low values but it shows correct a/f on the wideband then thats what the engine wants.

This is one reason why you should never mess with pre-made maps, use maps or even base your own maps from other engines. Never tune without a fast wideband a/f sensor.

The factory ecu is also a heavy interpolator! It always reads from at least 4 points on the map at once and averages between them. If the load and rpm values exactly match those of the map points then it will of course use the exact values in the map. As an example if you have map points at 5000rpm and 5500rpm but then engine is at 5250, the ecu will use a calculated map value exactly half way averaged between the two. So its a form of averaging, weighted towards the nearest map point. I don't think i explained that very well but do a google on interpolation if you need a proper explanation.

It is just important to remember this when you have sharp transitions on your map. It helps to set your map rpm and load points correctly to avoid any issues.

More later.....

Edited November 19, 2006 by TSL