Siege

iTrader: (2)

I am working on my boost curve and I'm having an issue I need some help with.

I am tuning the "MAF IAT WGDC Correction" table to maintain the same pressure independent of temperature. I have it pretty well dialed in but with any WGDC setting higher than 99 the boost rises significantly until the error correction takes over causing a huge dip.

I've tried limiting the max WGDC using the "Max WGDC vs Coolant Temp" and "TPS WGDC Correction" tables by setting the top values to 99 but the boost is still rising above 99.

What table can I use to cap the maximum WGDC preventing overboosting?

Any advice would be greatly appreciated!

Siege

iTrader: (2)

To word this another way, it looks like the "MAF IAT WGDC Correction" table overrides both the "TPS WGDC Correction" and "Max WGDC vs Coolant Temp" tables which doesn't make sense to me.

Can anyone confirm if this is normal or if there is another table that takes precedence over the "MAF IAT WGDC Correction" table?

400s

Are those WGDC's post 5,000 rpms abit too much?

Siege

iTrader: (2)

Thanks for the response!

The WGDC values are definitely on the high end probably since I'm using the stock Evo IX waste gate actuator. Replacing that with one with a higher spring pressure would definitely resolve this problem by lowering the WGDC overall.

I've continued to research since posting and it looks like the MAF IAT correction takes place globally so there is no way to limit the WGDC without lowering the boost at cooler temperatures.

CDrinkH2O

iTrader: (7)

I had this same problem. The solutions are as follows in sequence:

1. Upgrade your stock WG control valve to a GM 3 port or equivalent to increase control at lower WG duty cycles
2. Shorten the arm length of your stock WG actuator to increase spring preload, but still allow it to open fully. This will allow you to reduce your WGDC overall. Once you get above 95% it is impossible to control boost.
3. If you already did (1) & (2) Upgrade to a WG actuator with a higher rated spring - recommended FP 19 or 25 psi or Turbosmart IWG-75 with a range of different springs. This will get your WGDC back to a range which will allow you to regain boost control.

Siege

iTrader: (2)

Thanks, I appreciate the response. I am already running a 3port GM solenoid but I haven't modified the wastegate arm to increase the preload. I have it as tight as possible without modifications.

Ill look into an upgraded wastegate actuator to solve this problem.