Hi, I mapped my golf 2.0 TDI from a piece, and right from the beginning I did a log with vag and I have seen that the value of the mass air flow sensor to get the rpm drop dramatically. For example, to 4000 rpm, the turbine is still 1.3 bar but the maf marks around 1000mg/stroke. Should not mark 500x2.3=1150? Then one other thing, the maximum value is about 2300giri and turbine to 2.6 bar, and at around 1200mg/stroke. Is this normal or is something wrong?
According to me it is normal. In the engine the suction phase does not stop at the lower dead point, but continues for a certain period, let's say, hypothetically, for 20°, in which the valve/, and continue to remain open and to flow air in the cylinder, but in the meantime the piston back up towards top dead center (say that 20° c correspond to a lift of 10mm, values, fired at random, but to make the example), so in reality the volume of the cylinder is not more than 500 cc (2 litre engine), but something less because the stroke is shortened compared to the theoretical one, and then if you calcolassi for example, the volume with a run with real data from the theoretical minus the part that goes through the piston during the ascent you would have for example a volume of about 430cc that multiplied by 2.3 will give the value found in the diagnosis.
Yes, I agree that the phase ends after a few seconds, but terminanfo after, in the moment intake that the initial volume that I lose the reward with an increase of the opening time of the valve. Mah, the mass air flow sensor will read well? And then I to 4000 rpm only sometimes I get that maf, at other times, I mark even 950, and as a result I have an injection of 53mg/cycle that is low, given that the original and 50. In fact, the machine by pulling the marece is slow to rise, but in the moment of an overboost at 2000 rpm you nail it to the seat, in fact the low I inject 70mg/cycle having a maf higher(1200)
but the value you read is just 2600mbar? because if so the turbine is charging to 1.6 (as it should be on a golf mapped to soft). the problem would be if charged at 2.6 bar (a value which a turbine of the original may not reach in my opinion)Originally Written by djang01
No No are 1.6 bar actual, 2.6-related, including the pressure on the environment. However, and mapped to 1.6 in an overboost and 1.45 constant up to 3600giri, then down to 1.3 to 4000
Yesterday I did a test with my car (147 1.9 mjet 16V 140 Cv), which is the original, and with a little diagnosis I got these data, Intake Manifold Pressure(kPa) 230, Engine RPM 4109, and the Mass Air Flow Rate(g/s) 138,690002441406, then, following the reasoning of the unitary displacement/pressure I should get 1909/4 = 477*2,3=1097 mg/stroke, while the value found is 1012 mg/stroke is obtained by this calculation, 4109 revolutions per minute correspond to eur 68.4 rpm/sec, and then 68,4*2 = approx 137 aspirations per second. Then dividing the 138,7 g for 137 aspirations are, in fact, 1012 mg/stroke. Seen that, more or less, the pressure and the displacement are similar to the data you have indicated a value close to 1000 mg/cycle I believe is within the norm. I would add, however, that from the original map in the regime of maximum power, and then with a quantity of air is similar I see that are injected into the 62.5 mm3 in my engine then I 52,5 mg, therefore, in line with your data.
The fact is that I have mapped, the original pressure at 4000 rpm and a 25% lower. You can see that I have to further increase the pressure of the turbo to make it go
So tonight I've made other tests. I did a pull in third and I've seen that at 4000 rpm the pressure was 1.2 bar. Then I put hand to the map and I brought it to 1.38 bar by changing the map turbo and rev limiter. I go on the road, I once again pull in third and I saw that the target value was 1.38, but the real 1.2. The geometry always from the diagnosis was open to the 28% it seems to me, but I have to check. Before 3700 rpm about the pressure target is the same as the real one, then it falls. It is normal, the turbine goes into cavitation already at 1.2 bar??
I have mapped some of the.
you can raise the map turbo as much as you want, does not raise the pressure, or rather decreases even after 3500 3700.
experiment by increasing the 2 maps vgt an overboost, towards the end of the map, and then recheck the pressure. they try to inject something more of up to 4000 4200.
I have already given a bit of diesel on the top by increasing the map smoke, but if I go over fumicchia a bit. You say that if you increase the map n75 pressure rises? How much I could push myself as a pressure with the turbo stock around 4000giri?
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