Hi guys,

First attempt at writing a new map file for my Fabia VRS.
Been doing quite a bit of reading and so the general approach I took was to increase the DW, SL and TL maps up in the upper areas on the map.

Observed the maximum fuel IQ to now be just under 75mg/st and hence updated / adjusted all the other relevant maps to cater for this, including turbo maps to keep the AFR reasonably high and hence reducing any unneeded smoking.

Any comments on good points / bad points are appreciated as it will help me to learn :)

List of maps updated are:
EGR
Driver Wish
Torque Limiter
Smoke Limiter
IQ by MAF limit
IQ by MAP limit
SVBL
Injection Duration (0 - 5)
Boost Target
N75
Boost Limit
SOI (90degC)

Car already has a 175bhp map on it and runs fine with no smoking or clutch slip, however I have observed the map has been constructed with the injection duration maps 'decalibrated' and hence wanted to have a go at creating a map myself which kept the pre-defined areas of these as existing, then added in new columns (via linear interpolation) for the increased injection quantities :)

Thanks in advance :)

And the original file too!

quick look @ it I see blocks of % tuning no calculations involved

I will look in to ur durations later and see if u done this and if it is looking ok or not

you need to read abit more
Your Smoke Map is Linked to your Boost Map so u need to work out if u run X Boost you will have X airflow @ MAF So u Can Burn X fuel @ your AFR of your needs 16/17 is a good figure to aim for Rather than guess numbers for axis to make afr

Eg MAF Smoke Map why Axis 1344?<----- your car will not use this row in the way this has been set up (Read how boost is linked to this map)
But Also U are Running MAP Based Smoke Limiter according to Switch
So if we look @ Axis in there last row Again 2.8Bar you are not running that boost and Don't if love ur turbo so that row will not be used so ur limited here to.

this map may work BUT I Don't like this tuning But u will not be getting all what u request in some maps Due to some Errors of % tuning in blocks

I will look in to the rest later

were see what others may say aswell

Thanks for the comments, finding it very interesting learning about all of this :)

The approach Id taken was to use % tuning on blocks of the drivers wish, smoke limiter and torque limiter maps.
With the injection quantities such that dw>sl>tl.

The largest injection quantity I seen on the torque limiter map was under 75mg, hence I constructed the duration and SOI maps with 75mg as the largest number, and used linear interpolation to determine the duration values and SOI for these.

For the target boost map I constructed it with 75mg of fuel as the maximum as before.
From what I worked out, at 75mg of fuel at an afr of 16.4, should have 1232mg of air and hence 2.6bar of boost.
I appreciate the car wont be injecting 75mg of fuel from the way the maps are constructed, but built the maps with the intention of having a little bit of room to change fuel quantities and boost pressure without having to reconstruct the rest of the map if needs be.

The 1344mg/st MAF corresponds to 2.8bar of boost (taking cylinder volume as 474 and air density as 1mg per 1cm3).
Used this higher value of MAF and MAP in line with the smoke limiter maps, where the largest IQ on the smoke limiter map is 76.8 and hence constructed the MAP smoke limit and MAF smoke limit to match.
(Where 76.8mg of fuel requires 1334mg of air and hence 2.8 at an afr of 17.4)

Hope this clarifies what I was trying to do :)

I see that most people calculate their AFR by Boost, but how do you do it if you change you turbo?

I think that in this case you will need to know how much Air does the turbo provide at a certain pressure, am i right?

Thanks

As far as I understand (anyone feel free to correct me if Im wrong!) boost pressure is a suitable way of determining the quantity of air delivered to each cylinder.

The boost pressure (manifold pressure) is measured at the outlet of the intercooler which is after the turbo, after the intercooler and is just before the air goes into the engine.

We know the volume of a cylinder (474cm^3)
We know that at 1bar absolute pressure (I.e. atmospheric pressure) we get 474mg of air in the cylinder (assuming that 1cm^3 of air has a mass of 1 mg and that the volumetric efficiency of the engine at that particular moment is 1)

We know that if we double the pressure of a gas inside a set volume, we will get twice the mass of gas inside the same volume.

Hence, by measuring the manifold pressure, we can infer the mass of air that will enter each cylinder (assuming that no other pressure drops (caused by flow restrictions) occur after the point of manifold pressure measurement).

If a larger turbo were installed, that could push a larger mass of air, then that larger mass of air, in the same space (i.e. the space from the outlet of the turbo through to the inlet of the engine) at the same mass flow rate, would result in a higher manifold pressure.
Similarly should the turbo be damaged or a smaller turbo be installed and the turbo could not push such a large mass of air, then the smaller mass of air inside the same volume, at the same mass flow rate, would result in a lower manifold pressure.

Of course if nothing was connected to the outlet of the turbo, or a very big engine was connected to a very small turbo then the turbo would go into the 'Stonewall' region (compressor choke) (i.e absolute maximum limit of mass flow rate for a set outlet pressure)

The inverse being if the turbo was connected to very restrictive pipework, or a very big turbo on a very small engine, the turbo would possibly go into surge where the turbo cant compress the outlet gas to a higher pressure and hence the flow of gasses through the turbo goes backwards momentarily (i.e. the minimum limit of mass flow rate for a set outlet pressure).

If you have a look at centrifugal compressor maps, explanations for these, and definitions of compressor surge and compressor choke then that should give you a better explanation that I can!

Hope the above helps :)

Jac

Nice help, can you tell me one more thing?

I'm trying to run a richer AFR so that i can lower the turbo temp. I tried a ~14 AFR and its still not smoking at all.

Another strange thing is that when i run my map trough Actions -> View Performance on VagEDC Suite the results seem to be the stock one's.

I will put my tune so that (if you want) you can see it.

My objective is to run a 75mg/stroke tune with a little bit richer AFR.

Thanks for the help.

Im not sure...but I think in the case of diesel engines, keeping the AFR high, is the best way to keep the EGT down.
I believe as well, keeping the SOI suitably early will keep the EGT down, as having a late SOI will mean a late EOI, and hence more heat being transferred into the exhaust, rather than the heat energy helping to force the piston down.

But the above is one for the more experienced folk to check on!

Just got the above from lots of different books and articles Ive read on the internet (although I could have read something that's wrong or misunderstood the articles!!!)

I think with diesels, its more or less a case of low AFR will lead to higher EGT and a higher AFR will lead to lower EGT.
Different to petrol engines where a rich mixture (low AFR) will give lower temps, an AFR near the stoichiometric AFR point will lead to very high temps and possibly too much temperature and detonation etc, and a leaner still (high AFR) mix will lead to low power and lower EGT.

As for the map, im afraid I havnt had a full look at it, you seem to have a sensible max injection quantity, and sensible max boost being requested with the axis changed etc, so while ive not had a full look at it, you seem to have done things sensibly :)
(Although again, the more experienced folks would be far better to look at it than me!!!)

Although, you don't seem to have an AFR of 14, it seems to be nearer 16 and above.
The rough way to calculate it is, boost (in bar (absolute)) multiplied by cylinder volume
(in cubic cm (as we are assuming each cubic cm of air has a mass of 1mg) with the cylinder volume being 474cubic cm - which is 474mg of air)

Divided by fuel (in mg)

((Manifold Pressure * Cylinder Volume)/(Fuel per stroke))
So from your turbo map (although your smoke limiter map doesn't have figures that are too far different), you have (at 1900 rpm) 2.5 bara manifold pressure, with 75 mg of fuel
from the above, that's 2.5*474/75 = 15.8 AFR

The above though, only holds true with a volumetric efficiency of 100%, and with air of mass 1mg per cubic cm.

The reason your performance increase isn't shown in vag suite is that you have only changed the codeblock 2 values. When you look at the performance map, remember to change the option in the drop down box from 'auto bank selection' to codeblock 2.
That way, you should see the increased performance in vag suite :)

I normally change both values in codeblock 2 and codeblock 5 as the person that showed me some basics on mapping said to do this...but he didn't know why that had to be done...and im afraid...neither do I!!!
Have tried to look it up before but with no success :(
(If you find anything saying about the difference between codeblock 2 and codeblock 5 please let me know!!!)

Hope the above helps!
Afraid im rather new to all this, but really enjoying learning about it all :)

Thank you for the quick response. Your help is definitely very important to my learning curve. :D

IF i figure it out i will tell you. About the AFR i can only confirm the EGT once i got the Gauge.

I build a Excell Calculator that is helping me to do the map math, tomorrow i will change the map to a richer AFR near 14~14,5 with the same Boost or a little bit higher (1,6) but this will depend on the AFR since i only did the Duration math to 80mg/Stroke.

I didn't touch SOI (i'm a little afraid of it) cause my research show me that for temps i better to have a late EOI that a earlier SOI.

I will look into the SOI limiters and try to bring the actual SOI closer to the stock limiter.

Little OFFTopic: In my country there is some tunners that can reach the 260bhp barrier with stock injection, and i'm struggling to reach the 14 AFR with 1,6 bar of boost.

Tomorrow some math will be done.

Thank you, great help you gave me. :thumbup: :thumbup:

http://www.dpchip.com/home/diesel-tunin ... tios-afrs/

http://www.bankspower.com/techarticles/ ... ays-Diesel

http://tripletdiesel.com/high-performance.html

The above links are similar to what I had read before on AFR, SOI and EGT
But will be interesting to see once you have an EGT gauge! :)

Easiest way to get your AFR lower (if you want to do that) is to just inject more fuel, for a set amount of boost from the turbo.
Or of course have the turbo create less boost at a set fuel injection quantity.

As I understand it, with the EDC15P ECU, the fuelling quantity is decided first, then once that has been decided the boost value is decided by the ECU depending on the fuel to be injected. The engine then works to achieve both the specified boost value and injection quantity.

To get an AFR of 14 with a maximum of 80mg of fuel being injected, then you want to have the turbo generate 2.36 bar absolute manifold pressure at 80mg of fuel.
However, I believe this may make the car very smokey! And possibly high EGT too!

Or another way to look at it, with a max turbo pressure of (for example) 2.6bar absolute, then you can inject 88mg of fuel per stroke and that gives an AFR of 14 too.
But again I believe this will lead to a lot of smoke and possibly high EGT as well!

In order to get the 260bhp, I presume that needs a turbo upgrade?
I know the injectors on the PD130 engines are good for a lot of power (but im not sure how much), but im guessing things like the head bolts, exhaust manifold, turbo etc all have to be upgraded!