Standard Pulsar vs Sunny ECUs

wow very nice information mate. Just a question it may sounds noob but does the load refers on the Throttle body? like when you WOT... Actually I'm trying to learning the basic ecu chip. and I'm using tunerpro and Nissan Datascan for Map Tracing.... As I post earlier that I already have the gtir factory bin file, basing on the primary map it seems it's the standard sunny gtir ecu.. Well i got that from the Nistune Rom pack so maybe I have the standard one.

Anyway I jus wondering it seems there are 3 different versoin of GTiR

RNN14 SR20DET : 54C00 (GTiR)
RNN14 SR20DET : 54C60 (GTiR)
RNN14 SR20DET : 69C05 (GTiR)

as for ECU are they interchangeable?

weblizzer wrote:wow very nice information mate. Just a question it may sounds noob but does the load refers on the Throttle body? like when you WOT... Actually I'm trying to learning the basic ecu chip. and I'm using tunerpro and Nissan Datascan for Map Tracing.... As I post earlier that I already have the gtir factory bin file, basing on the primary map it seems it's the standard sunny gtir ecu.. Well i got that from the Nistune Rom pack so maybe I have the standard one.

Anyway I jus wondering it seems there are 3 different versoin of GTiR

RNN14 SR20DET : 54C00 (GTiR)
RNN14 SR20DET : 54C60 (GTiR)
RNN14 SR20DET : 69C05 (GTiR)

as for ECU are they interchangeable?

Yes, each of the above ECU bin files contain the maps for Pulsar GTiRs (54C00 and 54C60) and Sunny GTiRs (69C05). If you have a mappable ECU you can copy any of those 3 bin files across to use whatever base maps you want. You can even mix-and-match fuel and timing maps if you wish.

On Page 1 I posted up some information on the load scales. They are essentially related to the MAF air flow and the current engine RPM. They are not calculated from the TPS (throttle position sensor) since the position of the throttle doesn't necessarily correlate with air flow - i.e. you could instantaneously open the throttle and still have weak air flow through the MAF.

I'll discuss the TPS in more detail once I put up information on overrun processes.

Hope this helps a little,
Dave

To help make the information more digestible, I placed both the fuel and timing comparisons into the very first post. This will keep all the information together so hopefully glancing backwards-and-forwards at the various maps will be a little easier now.

Cheers guys,
Dave

very informative post this hope this should be stick.. ... thanks for sharing keep it comin!

Hi Dave,

Btw, I just try to download the maps using map trace on NDS. and See what I found. I'm just bit confuse as it seems they have much different on the stock gtir or even on the jdm gtir map.



If you will check the map they much bit different. so as the timing.

weblizzer wrote:

Hi,

Apologies for the slow delay; I've been moving house this last week and have had very little time to check emails. I don't even have internet at the minute……. Like being back in the 1990s LOL. Anyway, the fuel map that you posted above is *almost* exactly equal to the standard Pulsar fuel map. On the first page I converted the raw values into predicted air/fuel ratios which is why they look substantially different to yours. Here are the raw values from a standard Pulsar GTiR ECU:



This graph is basically flipped vertically so my high-RPM speeds are at the top instead of the bottom. The blue regions of your graph (i.e. values over 192; low RPM and low engine load) correspond to regions of the fuel map where the ECU is trying to force a stoichiometric mixture (14.7:1) by using the lambda sensor.

I'm a little more concerned with some of the fuel values you have at higher RPMs and higher engine loads. For example, if you look at (RPM=2800, engine load=60), (RPM=2800, engine load=76), and (RPM=6000, engine load=66), your ECU is injecting quite a minimal amount of fuel. The high-RPM and high-load area (RPM=6000, engine load=66) on the standard Pulsar ECU is injecting '53', whereas your ECU is only injecting '39'. I'd be worried that these low spikes may lean out your A/F mixture significantly. Have you modified the maps in any way? Or is this the way you got them?

I'll hopefully be able to keep an eye on the forum over the next few days while I continue to move.
Cheers,
Dave

sorry to be a pain dave
but ive tried to study these maps/graphs and I ''if im honest'' haven't really got a clue whats what lol

can you explain it a little more please as its pointless me trying to make out im cleverer than I am  
what do the blue, green and red segments represent?
what are the load figures?
and what are the figures representing in the coloured areas, is it a/f or ignition advance?

if I can get my head round the graph a little more then il have a better idea of what im doing
thanks and sorry for being a dimwit lol

GTI-R US wrote:sorry to be a pain dave
but ive tried to study these maps/graphs and I ''if im honest'' haven't really got a clue whats what lol

can you explain it a little more please as its pointless me trying to make out im cleverer than I am  
what do the blue, green and red segments represent?
what are the load figures?
and what are the figures representing in the coloured areas, is it a/f or ignition advance?

if I can get my head round the graph a little more then il have a better idea of what im doing
thanks and sorry for being a dimwit lol

Hi Bob,

No problem at all; happy to help!

GTI-R US wrote:
what do the blue, green and red segments represent?

The graph is basically displayed on a sliding colour scale, where green equals small amounts of fuel, through to red which equals large amounts of fuel. The blue areas of the map basically show regions where the ECU is trying to force an A/F ratio of 14.7:1 by using the stock lambda sensor. These values are visible as those with a value greater than 192. If you don't care about which elements "chase" an A/F ratio of 14.7:1, then you can view their absolute fuel values by subtracting 192 off these numbers. Basically, (number+192) tells the ECU to use the lambda sensor to chase the ideal stoichiometric ratio. The first map shows the raw values (including those greater than 192 which show the RPM/load values where the engine chases an A/F of 14.7:1), while the second map shows the filtered fuel values (i.e. subtracting 192 from the large numbers to give the absolute fuel values):



You will see that low numbers (i.e. low amounts of fuel) are used at low RPM/load values, while high numbers (i.e. high amounts of fuel) are used at high RPM/load values.

GTI-R US wrote:
what are the load figures?

The actual load scale is calculated using the TP values, which correspond to the "Theoretical Pulsewidth". The TPS values typically refer to the "Throttle Position Sensor", which are not used in the calculation of the ECU load scale. In a nutshell, the ECU calculates the TP values using the equation:

Theoretical Pulsewidth (TP; basically the engine load) = MAF Lookup (essentially the airflow through the MAF) x Injection multiplier / RPM

This gives a value for the TP, which is then used to index the timing/fueling values as an input for the engine. You can imagine (from the equation above) that more airflow and less RPMs will give you a high TP value, and hence more "engine load". So now that the ECU can determine your engine load (from the above TP equation) and RPM values, it can find the cell on the fuel map that matches your current RPM/load values. Then, using the value printed in the fuel cell, you can easily calculate what the actual fueling pulsewidth will be:

Injection Pulsewidth = Fuel table [particular RPM, TP value] + Injector Latency + Various enrichments (which may correspond to different real-world corrections such as temperature)

It is important to remember that the load values (ie TP values) do not directly relate to vacuum/boost levels. However, these TP scales need to be updated depending on the boost you are running since more boost will result in higher loads on the engine. You can imagine that if you increase the boost, the airflow will increase, so the maximum TP value will also increase (since it's proportional to the MAF lookup). If you run huge boost and do not increase the TP scales, then the load value will max out early on when you come on to boost, resulting in the engine not being fed proper fuel/timing values for the high load levels you are running. Ideally you want the engines actual maximum load to correspond to the right-hand column of the fuel maps above. This will insure that the entire load range (idle to maximum boost) is contained within the fuel/timing maps.

GTI-R US wrote:
and what are the figures representing in the coloured areas, is it a/f or ignition advance?

The values printed in the fuel maps above are simple values that the ECU can turn into injector pulsewidth values using the above equation. If we use the above equation, we can calculate the injector pulsewidths (in milliseconds - ms) that the injectors will actually open for given a variety of RPM/load values:



I hope this helps a little. If not, let me know and I'll try to explain it better  
Cheers,
Dave

yes thanks dave that makes a little more sense now

so basically the pulse width (if you were mapping a car) is what you would increase to add more fuel under any given load corresponding to air volume to bring the stoich / afr/s in line with what they should be at a given boost and loading?

I know its a lot more complicated than that as you need to take into account the knock values too with adding ignition etc but am I on the right lines now?

think I need to read this a few times over to get my head round it a little more, never ever interested me in the past but will keep on your case now badgering you for info now I know what a clever chappie you are lol

one last question for today please sir........is the load figures in grey at the top the tps position then? still not 100% on what they represent
just read it again and they are given figures from maf, tp and tps which gives theoretical loads is that correct?

Haha, yes Bob you've got it now  

Basically, the injector pulsewidth determines how long the injector is open for. A long pulsewidth means the injector is open for a long time, resulting in more fuel being added to the engine. If you want to add fuel (which will lower the A/F ratios without changing other parameters such as timing), you simply have to increase the injector pulsewidth. However, there is an upper-limit to how long you can actually open the injector for, which is why higher-powered cars need bigger injectors (which can flow more fuel at the same pulsewidth). For example, take the injector pulsewidth above for a map cell (RPM=6800, LOAD=86)...

At an engine speed of 6800:
speed = 6800 rev per min = 113.3 rev per second

So this means the engine is rotating 113.3 times every second! This means…

speed = 113.3 rev per second
one revolution = 1/113.3 = 0.0088 seconds for each revolution

But one cycle is for the 'power' stroke, while one cycle is for the 'exhaust' stroke, so a total combustion process occurs over 2 engine rotations…

two engine rotations = 0.0088 * 2 = 0.0176 seconds

Therefore the absolute MAXIMUM time we can open the injector for is 0.0176 seconds with an engine speed near the redline (6800 RPM). Using stock 440cc GTiR injectors, the injector pulsewidth is 15.71ms, or 0.01571 seconds. This means that in order for the standard injectors to feed enough fuel into the engine near the redline they have to be open for a large fraction of the total combustion cycle…

injector open time = 0.01571 seconds
engine cycle = 0.0176 seconds
duty cycle = (injector open time / engine cycle) * 100 = 89%

This means that if we increase the power of the car, the standard injectors will quickly hit 100% duty cycle (which means they need to be open constantly to feed the necessary fuel into the engine). To get around this problem, we buy larger injectors (e.g. 700cc instead of the standard 440cc), which have the ability to flow more fuel at the same pulsewidth. This means that their open time can be reduced, resulting in a much lower duty cycle which is better for combustion, longevity, and general running.

Hope this helps,
Dave

GTI-R US wrote:one last question for today please sir........is the load figures in grey at the top the tps position then? still not 100% on what they represent
just read it again and they are given figures from maf, tp and tps which gives theoretical loads is that correct?

In reality, the TPS (throttle position sensor) does very little during normal operating conditions. The TPS signal is used as a small factor when determining the actual injector pulsewidth (see the equation for the pulsewidth, where this will come under "various enrichments", and in particular is related to the "acceleration enrichment"). But overall, the TPS signal will not affect what part of the map is accessed, nor will it have a dominant role in determining the overall fuel injected. The load values are just a number that the ECU computes that gives a measure of airflow through the MAF, as well as what RPM the engine is currently running at. These values come together to provide a load value, where high loads are represented by large airflow. The physical number isn't really important, just so long as you increase the load tables (i.e. make the maximum number go higher than '86') when you increase the power the engine runs at. If you don't do this, the ECU will reach a fuel/timing limit at a load of '86', even though the actual load experienced might be more like '120' (i.e. boost increased significantly).

Cheers,
Dave

got it now
its good to learn something new every day  
had the fundamentals in my head but never the theoretical side so that helps me hugely.

if you don't mind dave I may possibly drive over to you sometime early next year so you can show me how to map a car (obviously will be a paid job for you but with me badgering you and picking your brains during the process

would also be good if whenever you get the time you could write an insight into the fundamentals of mapping a car if its not too much trouble and you don't mind sharing your knowledge with us less privileged in the head department  

Bob,

I'm often over in the London direction with work, so would happily take an extra day to swing by your place and give you a walk through of what's required. All I ask in exchange is a passenger ride in your GTR  

Cheers,
Dave

lol im sure we can manage that for you dave plus a few parts too to take back with you and tea and cake of course.

im planning on getting some kind of standalone ecu for the rasheen so will be handy after ive bought something with hopefully the software to map it too as in the long term I want to learn how to map my own cars then only have myself to blame if I blow them up

GTI-R US wrote:im planning on getting some kind of standalone ecu for the rasheen so will be handy after ive bought something with hopefully the software to map it too as in the long term I want to learn how to map my own cars then only have myself to blame if I blow them up

That's exactly why I started doing my own mapping. It's a steep learning curve, but since you're not limited by an hour on the dyno you can play it conservative and make changes slowly, and more importantly see how each change affects the car under normal driving/race conditions. Plus, if you blow it up you can have fun rebuilding the engine again………………  

Dave

cheers dave for the help, your input on here has been fantastic, very much appreciated!

What a fantastic read !
Thanks for taking the time to document so much info Dave !

Really well presented - I could understand what you were explaining and i have no previous knowlegde of ECU/mapping and only basic mechanical knowledge - so spot on there mate !

could you please translate it in French (with no accent) please? i don't understand all    

watoga wrote:

weblizzer wrote:

Hi,

Apologies for the slow delay; I've been moving house this last week and have had very little time to check emails. I don't even have internet at the minute……. Like being back in the 1990s LOL. Anyway, the fuel map that you posted above is *almost* exactly equal to the standard Pulsar fuel map. On the first page I converted the raw values into predicted air/fuel ratios which is why they look substantially different to yours. Here are the raw values from a standard Pulsar GTiR ECU:



This graph is basically flipped vertically so my high-RPM speeds are at the top instead of the bottom. The blue regions of your graph (i.e. values over 192; low RPM and low engine load) correspond to regions of the fuel map where the ECU is trying to force a stoichiometric mixture (14.7:1) by using the lambda sensor.

I'm a little more concerned with some of the fuel values you have at higher RPMs and higher engine loads. For example, if you look at (RPM=2800, engine load=60), (RPM=2800, engine load=76), and (RPM=6000, engine load=66), your ECU is injecting quite a minimal amount of fuel. The high-RPM and high-load area (RPM=6000, engine load=66) on the standard Pulsar ECU is injecting '53', whereas your ECU is only injecting '39'. I'd be worried that these low spikes may lean out your A/F mixture significantly. Have you modified the maps in any way? Or is this the way you got them?

I'll hopefully be able to keep an eye on the forum over the next few days while I continue to move.
Cheers,
Dave

Thanks for your comments dave. Actually this is just only from a stock ecu that currently attach from my ecu. So it's not been touch yet. That is what i'm worried about too the ones you specified on which some higher load on higher rpm has samller values too so if I gonna use my rechip ecu soon so I'll need to increase those stuff? isn't it?

Anyway here is my timing map:



As I try to compare it to the one you have it seems it is a bit different and have some advance on some mid rpm.

weblizzer wrote:Thanks for your comments dave. Actually this is just only from a stock ecu that currently attach from my ecu. So it's not been touch yet. That is what i'm worried about too the ones you specified on which some higher load on higher rpm has samller values too so if I gonna use my rechip ecu soon so I'll need to increase those stuff? isn't it?

Yes, what you suggest would definitely help you tune from a more-stable starting point. If your ECU is standard, I really don't have any explanation as to why the fuel values are so low at certain points. When you start with a base map, I would definitely smooth out the fuel/timing values to match those of the standard ECUs I posted above. Remember, a Sunny map will be the most conservative and give you a little more headroom (just in case you make a mistake). Just take your time, monitor the A/F ratio, and have fun!  

Cheers,
Dave

Thanks Dave for a very helpful information.

With regards to the TP Load, let say If I want to run on 1 bar boost so means that this increase the load of my engine. So what would be the best tp scaling for this? Was there any certain gaps? on stock it seems it like +4 then +6 on tp scaling.... I'm tyring to change the tp scaling like starting on 48, 54, 62, 72, 84, 96

Would this be ideal?

weblizzer wrote:With regards to the TP Load, let say If I want to run on 1 bar boost so means that this increase the load of my engine. So what would be the best tp scaling for this? Was there any certain gaps? on stock it seems it like +4 then +6 on tp scaling.... I'm tyring to change the tp scaling like starting on 48, 54, 62, 72, 84, 96

Would this be ideal?

Yes, if you increase boost you will no-doubt increase the load detected by the engine. Running at 1 bar will mean your timing/fuel tables will most-likely slam into the max-load column (i.e. LOAD = 86 in the fuel/timing maps) once boost comes on. Normally 1 bar is still safe enough though as your actual load values might be 85-95 which means the extra load is still being handled reasonably well by the standard load tables. If you really wanted you could change the upper end of the load tables to slightly higher values to compensate for the higher boost values (you don't need to modify the lower end of the TP scales since this is off-boost areas and the engine loads will still be the same). This way, the fuel/timing maps are less likely to "slam" into the upper load columns, and instead more gently approach these under maximum load conditions. Something like this:



Hope this helps.
Cheers,
Dave

Pops and Bangs on the overrun

A while ago I was asked how some people tweak their ECU to give more pops and bangs on the overrun (i.e. after a hard run on boost followed by a coast in gear), so I thought I'd put up some information on what I've seen others do to achieve this. I haven't done this myself so I can provide exact values, but I can hopefully explain what needs to be modified should you wish to do this yourself.

Anyway, take a look at the standard Pulsar GTiR timing table:



Here you can see that if you drive gently (i.e. minimal throttle) right up to the redline your ECU will determine that the car needs an ignition timing of around 50 degrees BTDC (i.e. retarded by 50 degrees at LOW LOAD + HIGH RPM). Now consider the in-gear deceleration timing table when the throttle is closed:



When you have closed the throttle (i.e. lifted your foot off the accelerator pedal) and are in a gear (i.e. not coasting in neutral) then the ECU will ignore the normal timing tables and access specific timing values directly from this graph. Here you can see that at high RPM the timing is substantially adjusted to a value of around 30 degrees BTDC (i.e. retarded by 30 degrees). This means that the spark to ignite the fuel comes 20 (50-30) degrees later in the cycle, which means some of that fuel will be pushed out of the cylinder on the exhaust stroke while it is still combusting, resulting in pops and bangs in your exhaust. I have seen people take this graph and make it 20 degrees at all RPM values, which means that the spark to ignite the fuel would come 30 (50-20) degrees later, meaning yet more combustion would be after TDC resulting in yet more pops and bangs. I've even seen some maps that reduce this further to around 10 degrees (meaning a 40+ degree shift in combustion) for super-duper pops and bangs.

At some point though you will hit a limit with the combustion occurring so late that it damages post-cylinder components (high manifold temps, turbo failure, etc.). But in a nutshell this is a simple way of how some tuners add bonus pops and bangs on the overrun.

Hope this helps,
Dave

Ah Ah, will do that!!! so fuuuuuun!!!! lol

fred05 wrote:Ah Ah, will do that!!! so fuuuuuun!!!! lol

Also note that this will provide pretty big flames out the back too............. Just be careful though, you don't want to cook your car   

Dave