First VCDS data log- now what?

2009 GTI. Not tuned (yet). Engine replaced 5k miles ago. Looking to verify everything is running properly before tuning. Only did 4 parameters this time.

https://www.goapr.com/support/datalogging.php

This guide says to do 5 runs with 12 parameters each. I assume that's overkill for my purposes? I have a micro-can (no turbo mode), so not sure if it can keep up with all that data.

Any advice?

Not sure what you have done there.


I am assuming that the car seems to drive fine from a drivers perspective but you want to know if there are any shortfalls.

First look for any error codes, they generally tell you if there are errors.

Assuming you have no codes I would log:

RPM - Boost specified vs Boost actual (Group 115)
RPM - Timing per cyl (Group 3 and Group 20)
PM - Fuel requested vs Fuel actual (Group 230)

As stated on the APR page these are done in 4th gear. Generally I roll from 2500 rpm to redline. For them to be valid they really need to be done in 4th gear to get the engine under significant load.

This may be helpful. I made a short video on logging with the cable you have. LINK

Thanks. I'll make another log using those inputs and post it up later.

The previous graph had actual/requested boost. It looks like an overboost spike at the start and then a few psi difference between the 2 throughout. I'm guessing they should match more closely toward the middle/end?

drval85 said:

Thanks. I'll make another log using those inputs and post it up later.

The previous graph had actual/requested boost. It looks like an overboost spike at the start and then a few psi difference between the 2 throughout. I'm guessing they should match more closely toward the middle/end?

Click to expand...

Some minor overboost at beginning of curve is fairly common as it takes a bit for the wastegate to open get things under control. All of what you describe sounds normal.

I would like to see the right side of the graph that would show N75% values. Better yet just post the link to that log from Malone.

GTI's said:

I would like to see the right side of the graph that would show N75% values. Better yet just post the link to that log from Malone.

Click to expand...

Apparently https://log.malonetuning.com/chart/245047
It seems that N75 duty cycle is a tad high for this boost level, mine is between 45-50% max. at 450m above sea level. Also your spec vs actual seems a bit off. I would say you have a small leak, most likely a bad DV.

Have a GFB DV+ installed. I'll double check it.