VersaTune User Forum

Well I am kinda giving up on trying to put my foot down in the winter. At first my tune was not prepared for the winter and I was getting overload which was hitting fuel cut. Not a big deal as I upped those a bit more as they were set pretty low anyways. That stopped the fuel cut but the next issue was that I was still going over load target of 2.4 . I was hitting 2.7 and getting knock and my wgdc would drop to 0 trying to contain it. Timing would also drop as the ecu would do anything it could to get the load in check. I set my wgdc tables to 0 with a correction of +20 and that seemed to help but that day it was 50f and not 30f so that was likely more of a help. Today I tried adjusting BCS DC Adjustment IAT to aid in the colder temps and keeping boost in control. This did help and kept my load lower but boost was still climbing at 0wgdc up top. Does anyone have any other ideas besides keeping my foot off the gas when it is cold? I was hoping to have a single tune that would work all year round or even a car that would work all year round. I am not an expert tuner so maybe there is something I am overlooking. Any advice would be great. I live in Iowa where it is below freezing for 3-4 months out of the year.

I never had any boost creep issues with a more potent turbo, so it must be something else. I'd start looking at the EBCS lines and make sure they are all hooked up correctly. Also check the wastegate actuator arm and make sure it's moving (you can apply like 1BAR/15PSI of pressure from an air compressor on the WG nipple) and there's nothing blocking its movement.

Alternatively you could share a log with us, and if it's not a paid tune from an E-tuner you could also share the tune.

I am self tuned. Here is the log with the tune. This was just a quick pull to see if the change helped it. This tune does have IAT set even lower and I don't recall the values when I took this log. They were low but not as low as they are now.

It is a bitch to reach it, but you will have to increase the length of the wastegate actuator arm and see if that helps (I am confident that it will).
I understand that during warmer weather you did not have this issue, but because right now the preload on the WG arm is too high you probably exceeded the manageability threshold at some temperature point when the weather got colder.

Also, for such a big turbo the tune is very aggressive with the variable valve timing (I believe your VVT table is stock). I'd run 5 degrees of VVT less on those columns at 4000 and 4500rpm and zero everything out from 5500 on.

The thing is that the boost creep occurs right on those 4000-4500 RPM points, and even though in my opinion it's not the VVT causing it (even though lowering the VVT in those areas may help a bit in this case), running with such an aggressive VVT there will make response too violent for the turbo, drivetrain (no problem with its strength, but with grip), and boost control system. At 4000rpm there is no difference in feel if the turbo responds in 0.3 seconds or in 0.2, but the boost control system works with air valves which are slow.

So I need to remove pre-load from the wastegate? In the summer my spring was about 15lbs. Will this affect my spool in the summer time?
Thanks for the VVT info I am new to tuning so I am sure there are a lot of intricacies I am not doing. Any more info would be great. It would be a bit before I can get under the car and wrench on it.

Theoretically it will affect a bit the spool time in summer if you will have the same tune, but in practice you can make it even faster by commanding the wastegate more aggressively.
Higher preload or higher WG duty cycle has the same effect: the desired angle of the wastegate opening. However, the last approach will give you better control on boost, and the lack of it in this case results in creep and possible engine damage.

So loosen the WG arm a bit. This is the only right approach assuming this is the problem and you already eliminated the possible EBCS fitting issues.

I adjusted the arm 3 turns and it still takes pressure to get it on the arm. I will see what affect that has on it. Does the below picture look right for vvt?

https://snag.gy/JgLuMa.jpg

Yes, the VVT table looks better. But you will know for sure after you take some logs.
When you will log next time load this logging preset:
https://www.dropbox.com/s/vlfmsrs4pvvlo ... vtpre?dl=0

After you load the preset check again the MAP sensor settings just to be sure (Customize -> select the CS 3.5BAR MAP sensor).

Key On Pressure is 14.2

Here are two logs that I took, both got some sort of fuel cut. I had changed the tune to your recommended vvt and set wgdc to 0. I am still getting lots of boost.

It looks like you shortened the arm instead of increasing its length (0 WGDC)... so move the nuts in the opposite direction. Make sure you compensate for the amount you moved them now, and also add 2-3 turns to that.