VAGCOM data Logging

[phillip1978]

Hi all
I have a stage 2 APR tune, a BSH cai, and a APR tbe, recently it doesnt feel like its got the oopmh that it used to have. So i ran a vcds data log of the actual boost pressure that the car was pulling
i got 2200 subtract the standard pressure of the day which was 1000
it came up with 1200 which equates to
17.4PSI....wtf??
shouldnt i be getting 20 or 21 PSI

for those who have a vagcom can you run a data log of you actual boost pressure and post your max values up,
cheers
Phillip

 

[PRND[S]]

Do you have any codes stored in the ECU? Your DV might have gone bad.

 

[staulkor]

The equation to calculate boost is:

boost = (value - 1010) * 0.0145

1010 is current atmostpheric pressure in mbar. 1010 is a good average, but depends on where you are.

 

[phillip1978]

No fault codes came up, car is clean

 

[TSiUG]

When I was stage 2 APR I peaked ~18 psi....I am TSI, are u fsi or tsi?

 

[phillip1978]

I am FSI

 

[darcness]

Phillip we can't really help you without seeing your graphs and full logs. Just going by everyone's max boost pressure isn't going to tell you a thing. Everyone is in different climates, relative pressures, humidity, etc. You can't just take a max PSI and say, oh my car isn't running right. Way too many variables go into this. If you're meeting the requested boost of your ECU then you should be fine. If you're not, THEN you probably have a leak some where. Without seeing your full logs/graphs just going by your PSI isn't going to help us or you at all.

 

[phillip1978]

Mmm good point will run another log with requested boost aswell and post it up.
Are there any other logs that should be done that may help?

 

[Alex@unitronic]

The equation to calculate boost is:

boost = (value - 1010) * 0.0145

1010 is current atmostpheric pressure in mbar. 1010 is a good average, but depends on where you are.

exactly thats at sea level the higher you go the lower the value gets, i for example have 760 milibars of atmospheric pressure.

obviously also the higher you go the more the turbo haves to work to get the requested pressure thats why at high altittude turbos fail a lot more..

 

[Alex@unitronic]

Mmm good point will run another log with requested boost aswell and post it up.
Are there any other logs that should be done that may help?

ill suggest block 115, 020, 011.

 

[josein06gli]

I hit 20-22psi depending on weather. I usually see 20psi but sometimes it goes to 16-18psi with the same pull as 20-22psi.

 

[phillip1978]

Redid the test before i went out i cleaned the maf, the max boost i got was 2460 which came to 21 psi , (2460-1010)*0.0145,
So that seemed to fix that low readings i was getting :happyanim:, but it still feels strange
ran went as follows
3rd gear pull
start at 2000rpm
out to 7000rpm

what do you all think of the graph

or is this just in my head



below is the link with the data in doc form
View attachment log data.doc

 

[phillip1978]

Mmmm and shouldn't my actual boost be less than specified?

 

[RRacerguy717]

Mmmm and shouldn't my actual boost be less than specified?

Looks good IMO. These 2L FSI are load based so your boost and timing will flucuate depending on conditions if for some reason it dosnt like the little over shoot in boost it will limit the opening of the TB. Angle if its around @ 99 percent open the ecu is happy don't sweet it. The more unhappy the ECU is the more the TB angle closes and extreme cases it slams it shut. :thumbsup: Bob G

 

[phillip1978]

Cool, thanks for the clear up of that issue