Vag-Check: Replacing Analog LDA?

Hello,
I own a 486 laptop with VAG-COM software.
During my first diagnostic test, I noticed that the boost pressure was regulating at approximately 820 mbar (Vagcom value 1840 - 1020 external pressure).
Now I've read that the pressure is normally around 0.9 bar.

Since my laptop might be a bit slow (486 100MHz/16MB RAM with Windows 95), I downloaded VAG-Check for my PDA, and it looks something like this:
http://www.arlab.it/screenshots/groupbrowse.gif
(Screenshot from the manufacturer's website)

'Many people here are talking about pressure spikes up to around 1.2 bar before settling down to 0.9 bar. I can't replicate this on my computer; the maximum value I've seen is 1 bar, and that's also reflected in the log files.'

I'd like to know if it's even worth it for me to install an analog LVDT to see these overshoots, or should they be visible on a PC/PDA if they exist.

Where can I adjust something to increase the pressure from 820 mbar to 900 mbar?


Sincerely,
Jan.

Hi,

Use a 5-10 kΩ precision potentiometer and adjust it to the desired voltage divider ratio.

Okay, increase the boost pressure by 5%, then adjust the potentiometer to 95% (which corresponds to 9.5k ohms with a 10k potentiometer).

What you then have is a voltage divider with a small resistor and a large resistor.

Approximately like this: (A)---[small]--(B)--[large]----(C)

Then, measure the wires of your pressure sensor. One wire has 0V (ground), one has 5V (power supply), and one has approximately 2V (sensor value) when idle.
You need to disconnect the sensor cable. This will give you a section from the sensor side and a section from the control unit side.
Let's call them 2Vsens & 2VSG.

0V ==>> (C)
2Vsens==>> (B)
2VSG ==>> (A)

Then you can adjust the boost pressure as you like.

Machst du einen Fehler versucht der Turbo den Zylinderkopf vom Block zu drücken. Die Turbodrehzahlen steigen rekordverdächtig. Damit bekommst du deinen Motor ganz sicher kaputt. ASo, be careful.
If you turn too sharply, the control unit will no longer detect the oversteer.

I've had it installed for a year, and I've set the overpressure to 1.1 bar.
'Boost pressure adjustment is highly recommended if you're experimenting with boost pressure!'

It would be safer for the potentiometer if you optimized its value by replacing it with fixed resistors.

Excessive boost pressure actually wastes power and fuel, so gradually adjust it to find the optimal setting.

Best regards,

Thanks for the tip, I'll adjust my pressure sensor wiring accordingly.

But I don't understand how having excessive boost pressure can waste fuel and reduce performance.

Gasoline doesn't really matter to me.
The current fuel consumption is approximately 6 liters, and I occasionally use the heater quite intensely .
My modified Fiat 500 used to consume 11 liters, so even 8 liters for a diesel would be acceptable.

G3TDI wrote:

Now, I wanted to know if it's even worth it for me to install an analog LVDT to see these overshoots, or should they, if present, also be visible on a PC/PDA.

Hi Jan,

Overswings can sometimes be very short (around 0.5 seconds) and also quite steep.

Depending on the sampling frequency of your device, along with the motor computer, the peaks will likely always be displayed as too low.

Personally, I find digital displays for tracking dynamic processes to be quite annoying... I much more easily remember the highest indicator position than the maximum value of an "abstract" sequence of numbers.

Hi Ulf,

Quote:

And I personally find digital displays for tracking dynamic processes to be quite annoying... a highest indicator position sticks in my memory much more easily than the maximum value of an "abstract" sequence of numbers.

...I completely agree with you!

By the way: What kind of analog LDA do you have installed (manufacturer, model), and most importantly, where did you install it?
I've often considered it, but I haven't been able to find a suitable place to install it. On the one hand, the display should be easily readable while driving, but on the other hand, it shouldn't detract from the interior's appearance.

I am grateful for any good suggestions!

Regards,
Alex.

donalexo wrote:

What kind of analog LDA do you have installed (manufacturer, model), and most importantly where did you install it?

Hi Alex,

Brand: Unknown Renault supplier.

Type: Advertisement from a Renault 5 Alpine Turbo.
Removed the mechanics, repainted the dial, and fitted it into the Golf dashboard.

It would probably be difficult to build something like that again, due to a lack of materials .

@ulf:

My respect, Ulf. The installation is really impressive.

Well, but imitation is really difficult!

Regards,
Alex.

'By 'excessive boost pressure,' I mean forcing your turbo to pump significantly more air into the cylinders than is necessary for clean combustion.'

I've heard rumors that a loader of the size of a VNT15 requires approximately 20 horsepower in normal operation. (Has anyone actually calculated this?)

So, if you increase the pressure and therefore the amount of air, I would say that the power requirement increases roughly in proportion to the pressure, approximately to the power of 2. This means that it doesn't take much for the same turbocharger to consume 30 or 40 horsepower. Now, the question is: ...

Where does this performance come from?

Right, the back pressure from the exhaust aftertreatment system covers the cost, because that back pressure increases. However, this reduces the engine's power output, while increasing fuel consumption, both for diesel and for the lifespan of the turbocharger.

Okay, so: Have someone follow you with their phone, and they should look at your exhaust pipe.
(Old racing driver saying: I don't care who's behind me...)

And then, keep testing until you reach the soot limit.

I don't have any problems with soot anymore.
'But I installed the potentiometer today, and now the pressure is settling at 0.95.'

In the recent ULF permeability test, I achieved a slightly better result, but my top speed remains the same.

donalexo wrote:

My respect, Ulf. The installation is really impressive. Well, but imitation is really difficult!

Hi Alex,

I have one more: a 2001 Ibiza with a Conrad-LDA. The part number doesn't matter, as it has been discontinued .

The rear section was radically shortened, and the hose connector was re-soldered *carefully*, so that the front of the display wouldn't collide with the steering wheel, and yet no hole would have to be cut in the plexiglass of the instrument panel.

Illumination via 3 super-bright red LEDs in series, recessed into the back of the housing -> space-saving and matching the red color of the Ibiza instruments.
To maximize light output, I spray-painted the inside of the housing white after removing the measuring device.

Covered with black adhesive film on the outside.

The "sunshade" prevents the reflection of the illuminated LDA (Lane Departure Assist) from appearing on the windshield at night.

1. Solder the upright bracket to the bottom of the housing for attachment to the instrument panel.

Hi,

Perhaps my creation is easier to build .

The lens hood is not yet attached, which is why it's slightly crooked.
Actually, it's really, really easy to install a child seat in a third-generation Volkswagen Golf.

Greetings.
Thomas.

Thomas wrote:

However, it is actually very, very easy to install an LDA in a Golf 3.

Hi Thomas,

"That's where my main power switch is for my LoFi setup... I'm just wondering if the steering wheel might obstruct the view of the LDA (Lane Departure Assist) system."

Hi,

Main switch for LoFi? I don't really understand that.

Quote:

Does the steering wheel rim actually obstruct the view of the LDA (Lane Departure Assist) in this area?

No, not at all. I think it's mainly due to the seat position.


Aaaaaaaaber ! Important!

If anyone feels compelled to do so and happens to see the lens cover at Oettinger, they should know that it's complete nonsense!
The website mentions a high-quality plastic bezel, etc. However, the part doesn't even fit properly. Additionally, you would need to remove the lower right mounting screw of the speedometer because the cutout for the display is too far to the left.
However, it is very expensive.

Greetings.
Thomas.

Hi Thomas,

Thomas wrote:

Main switch for LoFi? I don't quite understand that ?

LoFi as the opposite of HiFi. Ulf is a minimalist, isn't he?

Bertil wrote:

LoFi as the opposite of HiFi. Ulf is a minimalist, isn't he?

Hello.
Before more guessing ensues: a somewhat flawed (and certainly not overly expensive) attempt to install a bit of Hi-Fi: a decent homemade subwoofer in the trunk and 2-way coaxial speakers in the dashboard compartments, which sound a bit shrill despite the small equalizer.
Powered by 4 x 25 watts, it delivers plenty of power for loud sound and lots of fun with the bass.

LowFidelity, just .

... and the next post, please stick to the topic again, otherwise where will we end up .

ulf wrote:

LowFidelity indeed

I'm just saying...


Back to the topic: Does anyone have any ideas on where I could implement the LDA (Landing Data Analyzer) in the G4 (presumably a specific aircraft or system), preferably in a discreet way?