[zax]

So this is out on a limb because I'm a nuts and bolts guy and not a particularly bright technical mind. Could there be a intake temperature/air density correction there to prevent overboost that could be at play here

Yes, definitely. There are airmass compensations for all relevant boost boost control tables. However, TD-Boost Error is supposed to be the remaining boost error after all the compensations to boost targets are applied, and is the principal input into the TD tables below. But you do make a good point... if OP is seeing normal boost error in milder temps, adjusting the main TD-I or WGDC tables in colder temps may lead to boost spikes or even underboosting. I would probably try to play with the IAT comps in the TD-I portion instead.

TD-I:

TD-P:

WGDC:

 

[zax]

I'm going to go out on a limb and say that when OP runs the stock map, the TD Boost Error comes back down to within the acceptable range.

Cobb did indeed tweak the airmass compensation for WGDC quite aggressively for the EJ motor. I won't share the actual numbers from their map since it's their IP, but I will share the differences to stock map. Don't know if this is the case with the FA as well.

 

[Arnieduke]

Aight, here's Stage 0. Felt similar, still quite responsive, similar ambient temperatures as Stage 1 HWG. I'll let the graphs speak...

 

[zax]

OK, this looks much better. TD Boost Error is where I'd expect.

You must have just reflashed before the log since the DAM is still climbing. While it will indirectly affect your target boost (lower load due to pulled timing; boost control is load based via RT tables), it shouldn't affect your boost curve.

It's interesting because most FA WRX on the stock map have a very aggressive boost control that uses TD-P very actively (you've seen the boost spiking on OEM map). In your case, the TD-I is definitely utilized to hit target boost. Might be the cold weather and compensations.

My recommendation is that you wait for it to get warmer (0-15 deg C) and do a log then on the Cobb maps. It might just be that Cobb maps aren't optimized for the sort of cold that you are currently seeing.

 

[nimdabew]

How do you keep your nips from tearing through your shirt at those temperatures. God damn.

Band-Aids and vaseline. I spent two winters flying in Bethel, AK as a bush pilot. It was usually -20C and sometimes dipped to -35 or -45. It wasn't a whole lot of fun.

We went so far as to tell the new pilots they had to breath through their noses after drinking hot coffee so they didn't crack their teeth.

 

[zax]

Damn.

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[XJman]

I'd burn my own skin for heat.

 

[Arnieduke]

It has been warmer and I haven't heard back from Cobb support yet after sending them both logs. I flashed the car back to Stage 1 normal wastegate and so far I've seen boost numbers in the 16 psi range. Looks to me like the ambient temperature has a big impact, not sure if it's Cobb's map or a general thing...

 

[zax]

It has been warmer and I haven't heard back from Cobb support yet after sending them both logs. I flashed the car back to Stage 1 normal wastegate and so far I've seen boost numbers in the 16 psi range. Looks to me like the ambient temperature has a big impact, not sure if it's Cobb's map or a general thing...

Both, but if the FA is like my trusty EJ, Cobb's compensations are more aggressive at those low temps.

 

[Arnieduke]

Still no response from Cobb support. Maybe it's me, but the car seems slower on Stage 1. Any thoughts?

 

[Blk18wrx]

Alot of people think that because you loose that super fast boost ramp up. With stage 1 the power curve is more linear, and you won't have the drop off of power after 4500 rpm anymore.

 

[Arnieduke]

Cobb finally replied:
"Thank you for sending the logs over. The data shows the vehicle underboosting with both the high wastegate map and the Stage 0 map, which is our replication of the stock tune. Your TD Boost error is in the 2-3.5 range. The OTS maps do not overcompensate for very low temperatures, you should still be hitting target boost unless there is an issue present. I understand that this is a brand new vehicle but it is not out of the ordinary for a small issue like this to present itself early on. I would again recommend having a pressurized smoke test performed on the vehicle."

Comments? Anything I can do in my garage without having to pay for a test? Can't exactly bring this to the dealership... I remember seeing a video about spraying WD-40 around the hoses and watching the idle - was that Scotty Kilmer's video?

 

[zax]

If you are under warranty, you should take it in. Worst they can say is no.

Don't try to hide the modifications from them, just be honest and up front.

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[Arnieduke]

The dealership I got the car from is pretty intolerant when it comes to mods. I would expect the mere mention of an AP causing them to categorically bill me for all work. One could argue that ECU modifications don't affect the integrity of vacuum hoses, but in the end, it's them making the call.
You got a point though - they can say no to a warranty claim in the worst case.
I tightened all hose clamps I could find and did spray some WD40 at the connections. No change in idle. On the way home i got 17 psi boost peak during a highway pull in 6th gear. Need to mull this over...

 

[zax]

At this point, you know what you should be looking for. Ultimately your call. You could do the check yourself -- checking vac lines is tedious but not rocket science.

 

[Arnieduke]

Update: had a smoke test done and it was determined that there is no intake or boost leak. Numbers have been higher these days with the weather warming up, but still not seeing the 19.5 psi advertised by Cobb. These days it's around 17-18 psi. The guys at the tuner place I had the test done agreed with me that OTS maps are not a fit-all solution and that's possibly the reason for what I'm seeing. At least I know nothing's wrong. My ultimate goal is a custom tune once I'm ready to go Stage 2.