Can you revert back to the stock tune and see if you get boost again?
If that fails then you probably have a boost leak somewhere.


Sent from my iPhone using Tapatalk Pro

 

I was able to hit peak boost ~15-17 PSI earlier today before the flash.

 

Reset the ecu (leave the cobb map on) and see if you can hit target boost. If that doesn't work flash back to stock and then reflash the regular stage 1 again.

 

I tried resetting the ECU and flashing again, but no luck . I’ll try to uninstall, re-install, and flash Stage 1 again. I also submitted logs to COBB to see what they say.

 

I flashed my 2017 STi with my Cobb AP to the Stage 1 ACN Boost Select and noticed that my peak boost didn't hit 10 PSI. I switched to the Stage 1 ACN Boost Select HWG and wasn't able to hit 10 PSI either. I also noticed that the twitchy throttle response from the stock tune on S# has been removed with the Stage 1 maps.

Here are my data logs on the Stage 1 ACN Boost Select HWG. Everything seems to look ok, but I'm not able to reach anywhere near the target boost of ~17 PSI. My TD Boost error reads from ~-6 PSI and up to ~8 PSI. Obviously something is wrong there, but what should I check?

Dropbox - Cobb AP Datalog - Stage 1 ACN HWG.csv

No engine mods besides COBB catback.

The log you linked did not have any WOT. Do you have a WOT log?

 

I don’t specifically have a WOT log, but around line 375 you can see me start to pull and there’s finally some wastegate action, but I only took the car to ~4700 RPMs because the boost was nowhere near target boost and had no intention of building. It felt like it was hitting a wall like it was in “i” mode or had a valet map flashed.

I uninstalled the AP this morning before work and was able to hit stock peak boost of 16.2 PSI so there doesn’t seem to be a boost leak.

 

Without a WOT log, you're not going to accomplish much here.


What was your DAM?

 

In the log file I have in the OP the DAM is 1 the entire log.

 

Ah, yes... I had scrolled over as there is a lot of things in the log. If you want to get real data and input, do a pull in each SI setting and post the log (pulls only).

 

Well I reinstalled the AP with a Stage 1 ACN map directly from the Cobb site and still the same results. I attempted a WOT log from 3rd, but I didn’t see the point of taking it to close to redline as I didn’t want to cause damage. The log results are the same as the ones posted in the OP.

I also tried flashing the regular Stage 1 map (Not ACN) and had the same results. I’m located in Northern California at sea level and it’s about 55F.

As a note: this AP was purchased several years ago for my old 06 STi. I sent it to Cobb last week to get it reprogrammed for the 17 STi and receive it back yesterday. Is it possible that the AP was configured incorrectly and is installing the maps with errors? It’s an AP v3 SUB 4 now after the reprogramming.

 

I flashed my 2017 STi with my Cobb AP to the Stage 1 ACN Boost Select and noticed that my peak boost didn't hit 10 PSI. I switched to the Stage 1 ACN Boost Select HWG and wasn't able to hit 10 PSI either. I also noticed that the twitchy throttle response from the stock tune on S# has been removed with the Stage 1 maps.

Here are my data logs on the Stage 1 ACN Boost Select HWG. Everything seems to look ok, but I'm not able to reach anywhere near the target boost of ~17 PSI. My TD Boost error reads from ~-6 PSI and up to ~8 PSI. Obviously something is wrong there, but what should I check?

Dropbox - Cobb AP Datalog - Stage 1 ACN HWG.csv

No engine mods besides COBB catback.

In all 3 modes? Cobb sets the boost in I mode to 8, s to about 15 and s# to 17/18.

 

Yup, all 3 modes were limited to 10 PSI and I didn't feel a difference in between any of them. I even installed their Stage 0 map which mimics the stock tune, and that was limited to 10 PSI. I feel like there is something wrong with my AP.

 

I highly doubt it is the AP... If I had a WOT log, I could see exactly what it going on though.

 

Here is the 4th gear WOT log. I don’t have an area to pull to redline safely so I hope this is enough data. I just installed the AP and flashed the Stage 1 ACN boost select map this morning and I was able to hit the target boost range ~16 PSI. Apparently I wasn’t pushing the throttle down far enough to justify “100% acceleration”. However, when pushing the same amount on the stock tune, I was hitting 100%. Please let me know if you see anything out of place or need more data.

Dropbox - datalog6.csv

 

After seeing that, I'd do a boost leak test. Since the stock O2 is not usable when in boost, I can't tell how rich it's actually going. The log itself does not point to anything other than it might be loosing boost and then trying to correct. Though Target Boost is not logged, the TD Boost Error isn't off by a huge amount.

You did hit almost 17 PSI in that log, so that is promising. From what I am seeing, you might just need to go over the car. If you have an air compressor, you can boost leak test the car yourself, pretty easily. You can also do a 3rd gear log as that gear is long enough for good data and should let you wrap it out to 7k RPM.

 

I'm pretty sure whats happening is that the throttle map changed on the new map. The stock map ramps up very fast so that you hit 100% throttle much sooner in the pedal travel range. The COBB maps are usually more linear so that you have more pedal travel between 0% and 100%. So basically you have to flatten the pedal to hit 100%. Try a few more runs and see if this works.

 

The boost curve at 100% throttle in the last log is not smooth.

 

Can a leak from the intake sound generator cause this issue? Should I buy the ‘15 / ‘16 elbow tube to remove it?

 

You'd be looking for a leak after the turbo.

 

Would the leak after the turbo cause a loss in back pressure and therefore boost?

Thanks for all your help so far by the way!

 

By "after the turbo", I am still referring to the intake tract. From the turbo compressor outlet to the heads (including intercooler and intake manifold).