Audi 2.0t pulling timing

[AMGROAR]

The car actually drives very well! Except for not making as much power as I hoped, but it's still pretty good.

I think that log was the first time the car was driven after flashing it... I've found it'll do some strange things until some adaptation has happened. I suspect if I took a log today it would look better.

Massive timing variations seem to just be a characteristic of this engine... it does it even on the stock tune. I suspect they may be using timing as a fast way to control torque, so for example when you lift off the throttle a little, it pulls timing to reduce torque until the throttle plate and turbo can catch up.

Do you see overboost code with your calibration? or a EPC light? Also thank you for a nice discussion here. I learned a lot of things from your discussion and calibration file.

[bb-tt]

I did have something happen recently that may have a bearing on this. One of the parameters I've been looking at to gauge my tuning results is MAP (manifold absolute pressure). And another project I've been working on lately is building a boost gauge for the car. I was doing some research in relation to that and just this morning realized this engine (CAEB) doesn't have a MAP sensor! So something in the ECU must basically be computing a "fake" MAP value based presumably on MAF and RPM and maybe intake air temp? Anyhow, I'm wondering if any of the tables I've been messing with are just there to support that function.

Edit: I realized I left out an important point from the above. And that point is that if one of these tables is creating a "synthetic" MAP number based on other factors and I edit that table, a) I could think I've increased the car's performance when I actually haven't - I don't have access to a dyno so I'm mainly relying on seeing an increase in MAP and MAF to verify I'm changing the right things. And b) if the ECU is using that synthetic number for monitoring or something like that, the ECU could be doing things in reaction to the manifold pressure being higher when it actually isn't.

The CAEB absolutely has a map sensor it is installed in the charge air pipe between the intercooler and the throttle body part # 038906051E IMG_20180802_132945.jpg

[ELaw]

Uh... that's not a MAP sensor. The "M" in MAP stands for "manifold" - it's implied that it's the intake manifold.

That sensor does measure pressure coming out of the turbo, but except at full throttle, pressure in the intake manifold will be lower. For example, the intake manifold pressure is below atmospheric (vacuum) much of the time (depending on how you drive ;^) ) but that sensor will never show that.

[TylerJDubbs]

The CAEB absolutely has a map sensor it is installed in the charge air pipe between the intercooler and the throttle body part # 038906051E IMG_20180802_132945.jpg

reading is hard

[bb-tt]

Uh... that's not a MAP sensor. The "M" in MAP stands for "manifold" - it's implied that it's the intake manifold.

That sensor does measure pressure coming out of the turbo, but except at full throttle, pressure in the intake manifold will be lower. For example, the intake manifold pressure is below atmospheric (vacuum) much of the time (depending on how you drive ;^) ) but that sensor will never show that.

According to bosch and audi that is the MAP sensor on the caeb, also Ross tech has this explanation:

-Boost Pressure (actual) is the pressure actually seen by the MAP sensor. You should never see a value below atmospheric pressure since the MAP sensor is located upstream of the throttle body on the 2.0T engine.

[ELaw]

Well, they're playing word games or maybe it's a translation problem.

A sensor that measures pressure somewhere other than the manifold is not a manifold absolute pressure sensor!

Don't get me wrong - the output from that sensor is useful for measuring boost levels (when the throttle plate is fully open), but it's not the same thing as what usually is called a MAP sensor.

[bb-tt]

Well, they're playing word games or maybe it's a translation problem.

A sensor that measures pressure somewhere other than the manifold is not a manifold absolute pressure sensor!

Don't get me wrong - the output from that sensor is useful for measuring boost levels (when the throttle plate is fully open), but it's not the same thing as what usually is called a MAP sensor.

Ok semantics but the "map" sensor on the 1.8t is in almost identical location so while it may not be a true MAP that is what vw/audi refer to it as. Funny thing is when i read boost using torque app it does show negative pressure(vacuum).

Sorry Tylerjdubbs had not got that far or somehow skipped your post.

[Steven@HPTuners]

FWIW, in our software, we refer to MAP sensors as actual manifold sensors. We call the sensor pictured above the TIP Sensor, for Throttle Inlet Pressure.

[ELaw]

Funny thing is when i read boost using torque app it does show negative pressure(vacuum).

I may be remembering wrong since it's been a while since I worked on the car, but I think the ECU does output a value called "MAP". As far as I can tell it's a made-up number, probably derived from mass airflow, throttle position, RPM, and maybe a couple of other factors.

[bb-tt]

FWIW, in our software, we refer to MAP sensors as actual manifold sensors. We call the sensor pictured above the TIP Sensor, for Throttle Inlet Pressure.

Interesting, so VAG refers to it as the G31 sensor if that helps at all. It is in measuring block 115 or ide00191. The stock sensor is 2.5 bar so after subtracting atmospheric pressure it is good for ~22 PSI. 4 bar sensor PN: 0281006059

After i thought about this all the aftermarket parts dealers refer to their silicone pipe from air filter to the turbo as the TIP (turbo inlet pipe) which is where the MAF is. So it appears I am just confused by the different terminology. Oh well.

On a side note the Nefmoto forums had allot of info on older ecu not sure but they might have useful info on ME17.

[TylerJDubbs]

FWIW, in our software, we refer to MAP sensors as actual manifold sensors. We call the sensor pictured above the TIP Sensor, for Throttle Inlet Pressure.

yet in most cars ive logged it only outputs a MAP value and not a TIP pressure value... think you guys could get on adding requested TIP and actual TIP?

[TylerJDubbs]

I may be remembering wrong since it's been a while since I worked on the car, but I think the ECU does output a value called "MAP". As far as I can tell it's a made-up number, probably derived from mass airflow, throttle position, RPM, and maybe a couple of other factors.

im 99% sure this value is a calculation by the ecu from RPM, TPS, and MAF readings or fuel injector times like you think aswell

[Steven@HPTuners]

yet in most cars ive logged it only outputs a MAP value and not a TIP pressure value... think you guys could get on adding requested TIP and actual TIP?

Correct. We try to provide logging for everything we can find, but sometimes we miss some things. If we're missing things on a given ECU, the best thing to do is get a ticket to support so it can get to an engineer and we can track it.

im 99% sure this value is a calculation by the ecu from RPM, TPS, and MAF readings or fuel injector times like you think aswell

MAP is calculated on vehicles that don't possess one by using a manifold filling model. The model has a lot of different inputs, but basically works on an assumption of how much volume is in the manifold, how much air is going into the engine, and how much air is coming through the throttle body.
Provided your throttle body and speed density tables are accurate, it should maintain an equally accurate prediction.

[tomaptuning]

Ok semantics but the "map" sensor on the 1.8t is in almost identical location so while it may not be a true MAP that is what vw/audi refer to it as. Funny thing is when i read boost using torque app it does show negative pressure(vacuum).

Sorry Tylerjdubbs had not got that far or somehow skipped your post.

There is no such thing as negative pressure, vacuum is literally the opposite of pressure not negative.

[bb-tt]

There is no such thing as negative pressure, vacuum is literally the opposite of pressure not negative.

Agree just the way digital gauges display it.

[mukhery]

Interesting, so VAG refers to it as the G31 sensor if that helps at all. It is in measuring block 115 or ide00191. The stock sensor is 2.5 bar so after subtracting atmospheric pressure it is good for ~22 PSI. 4 bar sensor PN: 0281006059

After i thought about this all the aftermarket parts dealers refer to their silicone pipe from air filter to the turbo as the TIP (turbo inlet pipe) which is where the MAF is. So it appears I am just confused by the different terminology. Oh well.

On a side note the Nefmoto forums had allot of info on older ecu not sure but they might have useful info on ME17.

I agree the terminology is confusing, but I think you were correct in calling the sensor a MAP sensor as that is how VW/Audi and others (e.g., AEM) refer to the sensors without context of where they're installed. Any arbitrary chamber could be a manifold, right?

I also completely agree that Nefmoto has a ton of info. Based on everything I've learned so far, a lot of the older ECU information on there is directly applicable to MED17. Some of the parameter/table names change slightly (e.g., KRKTE to KRKATE), but much of the functionality seems to be the same. People on there have also posted lots of MED17 documentation. I've found one of the challenges is actually mapping between all the VW/Audi tuning info out there and HP Tuners' naming scheme. I bought a super mappack for my CETA and have found it really useful to be able to look up tables in the mappack per the VW/Audi names referenced on Nefmoto and then match it up with the tables in VCM Editor to understand what's actually getting changed.

Interestingly, I thought CETA and CAEB were almost identical, but my CETA is actually MAFless from the factory. Instead of a MAF, my engine has two MAP sensors, one in the throttle inlet pipe and another in the intake manifold. Given that we're running the same OS, it's probably possible to convert to MAFless/speed-density by copying the relevant codewords and tables.