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Few tests:
At readline:
R/S: 6137
Torque: 290 N/m
PS: 247
Speed: 115Km/h
Bar 0.24 (*14.5) = 3.58 psi only Does this prove that I have a boost leak?
I could reach max boost of 1.54 bar at 5000R/S = 22 psi
I could reach 399 Nm torque and 264 PS (with ron 95)
I don't think that my turbo was upgraded by previous owner because ECU firmware was stock.
I attach 2 pictures. First with the 2.54 (-1 bar to find boost). Second showing torque and power. So it is true, Q5 can perform better than advertised?? I have used bars because it is easier, above 1 is boost and below 1 is vacuum.
Last edited by apoelistas; 06-26-2017 at 01:55 PM.
Apps like you have are very good at accurately reporting RPM and vehicle speed from the OBD2 port. Boost is probably also accurate (with the adjustment for atmospheric pressure).
But, you should not take seriously the estimates on HP or torque. Those are indirectly calculated based on some assumptions that are not likely to be valid. You'll not see those numbers on a dyno.
No such app I've ever used calculated HP and torque accurately. The only one that even came close was based on acceleration curve from a data logging accelerometer with adjustment for vehicle weight. That got pretty close (G-Tech Pro) to my dyno readings on the Mazda. About all the HP and torque numbers you are getting will tell you is relative change from baseline when you make modifications or when you have a fall off in performance.
Your screen shot did not show the fall off in boost at redline. There are going to be experts in the 2.0T engine's boost curve at other parts of this forum where the engine is in other cars that are more performance oriented. Making only 3.6 psi boost at redline, if you are under load in a higher gear seems very low. I would expect to see something of at least 12 at that point for a K03.
You might want to ask the question in one of the subforums here where guys are racing or modifying the 2.0T turbo engine. My guess that they will have data logging data that could be evaluated to give you a decent baseline expectation.
Cheers. Very descriptive reply. I will try to upload a picture in 10 mins when I find the screenshot from the video. We have to subtract 1 from the boost reading. Audi promised to check boost pipeline, so on the 3rd of the month I will have an answer. Thanks for helping me out. I believe I have a boost leak, from your description. You have a lot of knowledge and I appreciate your time and effort you have given to help me out.
Last edited by apoelistas; 06-27-2017 at 10:01 AM.
I was thinking of purchasing this from Canada. It seems a perfect add on. It says that it is compatible to A4 B8 but I would think that for Q5 it would be the same. Need to ask.
Last edited by apoelistas; 06-27-2017 at 10:00 AM.
Those pod gauges are nice. On my little 'Speed 3 (MPS in Europe), I used a VDO purely mechanical vacuum/boost gauge. I just trust them more than getting the data second hand through the port. But most people feel completely comfortable getting the reading from the manifold pressure sensor via the OBD2 port.
Best wishes. Let us know what they find. At eight years old or so, you may simply have a small crack in a hose or boost tube due to age, time and engine bay heat, or a loose clamp.
Update:
I asked Audi to change 2 check valves (just from intuition and comments around the boards)
changed boost check valve/ pipe line.
changed second check valve (was bad)
Breaking has improved. No need to press harsh the break pedal. (I had break fluid low level warning too but Audi said that it is due to rotor wear, so I asked them to replace the check valves to be sure)
Also fuel consumption has improved. Now it is down to 12 l/100km average (I believe it will settled down close to 11).
Second part was to check for oil leaks near the intercooler. I found the oil return valve leaking oil which is a sign of turbo leak. I have ordered part number 06H145735G. I wonder why Audi mechanics did not observe this 2 times of turbo inspection and garage visits. Just needed to remove the plastic cover under the intercooler and inspect.
After having some trouble with oil consumption, dealer had previously cleaned the thread of the engine oil sump plug, I realised that the problem had become worst needing a liter per week.
Replaced also the oil sump cover at a mechanic next to my house, and now I have no oil under the engine. Seeing the oil plug, it seems that thread repair, using a bigger bolt/plug, was not done properly, and in addition the strengthening ring/wall from the inside, had broken leading to excessive oil leak. I will try to take a picture if my mechanic still has the part. I have installed the new part of oil sump with AA and seems that problem has disappeared. The installation was very difficult since there is not enough space to work under the oil sump. (remove and tighten the 19 bolts of the sump cover was really difficult)
Still have some spooling boost hissing, I am not sure if the problem was related to the oil return hose leakage problem which I have replaced (06H145735G), eg not enough turbo lubrication??? Might order the strengthening clip for the turbo, though my turbo diagram does not come with this. I will have it ready when I remove the front bumper, in order to replace the intercooler with a bigger one, and at the same time check all connections and see if that clip can be installed.
Last edited by apoelistas; 09-21-2017 at 11:21 AM.
Years ago our professor was discussing the old crude heavy V8 engines that were going out of fashion and the new options like turbocharged four cyinders that were coming out to replace them. And he summed it up very nicely by saying that yes, they were old and crude and big and heavy. But all they needed were fuel and oil, and that was a pretty good trade-off compared to all the extra expenses of design and manufacturing and maintenance that all the new complex systems needed.
One turbocharged four cylinder engine versus one small-block V8. The V8 has no intercooler. No turbine. No turbine oiling system. No turbine cooler. No extra piping. No waste gate, no pressure sensor, no computer control system and harness...You can buy an awful lot of fuel for the V8 engine, compared to the costs of all the extra parts the turbo system needs, and all the maintenance it will need. Small and light is good, but there's a very high invisible price for it.
06-26-2017, 04:32 AM
