I data logged the turbo, fuel system, exhaust temperature and torque for my remapped Skoda Rapid 1.5TDI Manual, and each data log for every parameter was repeated 3 times and the best result was chosen. Third gear was selected for all the runs since I do not feel comfortable with the 4th gear speeds on my vehicle. The figures given to me by my tuner, BHP: 140-142 and Torque: 300-320. As mentioned earlier I would be doing the data log in my previous post in which I had mentioned about my experience with a Tuned Diesel.
All of these was done on a sparingly used highway which is not yet opened to the public, but never the less I was extra cautious about everything.
A friend of mine accompanied so that I could just focus on the road and not get myself or anyone else into trouble. Parameters monitored are as follows( through a VCDS cable):
1. Engine Speed present in all the charts.
2. Charge Air Pressure (specified value) which means what the ECU is requesting.
3. Charge Air Pressure (actual value) what is being delivered.
4.High Pressure Fuel pump (specified value) what is being requested by the ECU.
5. High Pressure Fuel pump (actual value) what is being delivered.
6. Exhaust Gas Temperatures.
7. Torque Values.
These are monitored and the data was compiled in a website called
www.datazap.me and converted to graph form.I have manually converted the boost chart to psi for better understanding as it was in kPA. This was done in excel.

This is the overall chart and I will be dividing this into specific markers where I felt that values are important. As soon as the logging was started, I just kicked down the gas pedal, and it was not lifted of until redline.
Values at start of kickdown are below:

The requested was almost double at 30 psi and usually diesels can run higher boost as they do not have to worry much about preignition and various other factors. Charge pressure then increases rapidly as the turbo spools and when the engine speed increases and at one area you can see the ECU requests an almost linear amount of boost.
The picture of linear request vs linear delivery is below:

The peak boost reaches at ~3000 rpm and the value is around 38.8 psi and requested by ECU is at around 35 psi. The picture is below:
After attaining peak boost at 3000 rpm the requested vs actual starts tapering and as well the delta between the both is lesser as the turbo has already spooled to a certain speed and at close to redline 30 psi is generated which is close to the 29 psi requested. Alongside all this I had data logged the fuel system as well at the High Pressure Fuel Pump level as it is more relevant.
I has asked my tuner to adjust fueling so that I do not get any black smoke during acceleration and they told me they have cut the fueling in between the rev range.
The data log of fuel pump is there in one of my post where the pressure is logged along with temperature as the fuel can be used by the tuner to cool the engine components. The fuel pressure specified vs actual in correlation with engine speed is shown below:

The delta between the fuel pressure specified value and the requested is really less as you can see the 2 lines are almost very close to one another. As said by the tuner, he cut fuel at one of the rev range and that happens to be at ~1770 rpm. Picture here:

And then he restarts the fueling a little before 2000 rpm and gradually increases the fuel pressure in order to deliver more, to account for the more boost produced. The restart point goes up and reached another point from which the fuel pressure is gradually increased. Picture here:

What I could notice is that the prior tune used to create considerable amounts of smoke but now since the fueling is tweaked a little I can see some amounts of smoke but not considerable one like a "Black Cloud". But still there is black smoke and would welcome suggestions from experts. But the idea of cooling the engine using fuel might be used here. Need to confirm. If we see the numbers on the boost chart at the point at which the fueling was cut, then we can understand the reason why black smoke is a thing for tuned diesels.
So the point of cut off fuel is at 1777rpm to be precise and if we find the same rpm in the boost log we see that the requested boost by the ECU is not been delivered due to the reason that we do not have enough RPMs and the turbo has started to spool. Picture here:
Hence this is a completely satisfactory and numerically way to explain as to why the fuel pressure was cut off and reduced at that particular RPM. Prior to this adjustments, as mentioned on the top that I used to see a black cloud like smoke, which is now drastically reduced.
The reason for the black smoke before was continued fueling into the engine when there is not enough air for it to combust all of the fuel because the turbo is not able to deliver the requested value from ECU which lead to the engine running richer and hence the black smoke.
A better way and a more precise way to log this is using Engine speed vs Lambda which I will be doing in coming days to measure the deviation of Rich/lean combustion.
But these graphs were to explain as to why fueling is the most important and not just to get a tune/boost which makes power in an inefficient manner.
This carbon would eventually destroy the internals if too much of it is accumulated due to the tune, and would also result in blocking of the catalyst, increasing back pressure and causing damage, explains why some people remove it and do a downpipe, and many more problems, which I am glad to say is fixed to an exceptional extent with the Rapid, I am sure that little more fine tuning would reduce these levels to minimal as well, which is being worked upon.
Now below is the log of the exhaust temperature and torque. Exhaust temperatures increase exponentially with increase in power, and will eventually destroy the turbo if they get too hot.
The exhaust temperature was measured on VCDS but then the thing to note here is the placement of the sensor. Usually the exhaust gases temperature are in between 500 to 800 degrees Celsius and there is a detailed thread on the same in TeamBHP, link here:
https://www.team-bhp.com/forum/techn...haust-gas.html (Maximum Temperature For Exhaust Gas)
The placement for the sensor is before the turbo in the 1.5 TDI engines and at the exhaust manifold, the diagram of the same is here:

The label number 12 is the exhaust temperature sensor. Measuring the values itself is hard as the sensor is under immense load of temperatures, and uses a thermocouple for the same.
The drawback is that they produce a low voltage signal and this needs to be converted to higher voltage for the ECU to read, usually in between 0 to 5 volts. And we are measuring the result of the combustion and not what is happening in the cylinders, and all of these factors make the reading less accurate, but this is what we get from the factory and need to rely on it.
The data log of the same is here(Thing to note: This was done in second gear so values are less, will do it in third in the upcoming logs):

As you can see at the kickdown in second gear the exhaust temperature was at 195 degrees Celsius, this was a stop of 10mins, which is normal. I did not want to hold till redline in second gear as I felt it was not needed as peak torques would be achieved much before redline.
The exhaust temperature seems to be fine for an idling car and nothing to worry about, reference to the thread anything above 850 degrees Celsius would damage the turbo housing. The peak torque produced was at 332 Nm which is surely will give you the push in the seat type of feeling that too for a small sedan like Rapid. The peak exhaust gas temperature was at 630 degrees Celsius and I know that it would increase if we are constantly pushing the car hard, will only get to know in the 3rd gear log, but I am sure it would not cross 850 or so, fingers crossed till 3rd gear log on exhaust temperatures. Picture here of the peak gas temperatures:

Referencing the thread, if temperatures are too high (>900) then your remap might have fueling issue and it is better to log and fix it otherwise you may face problems with it. Peak torque picture here:
By deriving Hp from torque according to the measured graph we can get a graph of power curve as well, but I have done it only for peak torque value. Peak torque was at 2540 rpm as per graph and value was 332Nm, so formula is (2540 times 332)/5252 gives us 160Hp. This is not the correct way but just an idea to get as to what amount are you getting out of the tune. Dyno is a much more reliable, correct, safer way to do the same.
The tuners claim was at 140-142 which I feel is a handful amount with just a tune, and air filter swap.
That's it for now guys, experts please let me know if anything is wrong and suggestions to improve the tune further are very much appreciated.
I will be logging the intercooler, lambda sensor in the coming days. Thanks!