Hello,

I'm hoping to get some expert advice on how to go about rectifying an over-boost/boost spike condition I see around 3000 to 4000 or so RPM's or so. I'm running the stage 2 ACN91 2010 USDM MRv402 map (have intake and TBE), and other than the boost spike, I think it's running great. I'm seeing 29.5-30.5 psi for a split second before tapering off, and like to bring that down to a more acceptable range. Looking at the logs, i see that at that rpm range and throttle position, the load is around 280; however,in the map the Boost Control Load Offset is 110 while the Boost Target Engine Load tables is set to 150 at 80% Throttle position, meaning that I should be expecting to see 260 as the load on 80% throttle. By the way, why are no cells higher than 80% throttle in the BTEL tables? Does that mean than any throttle position beyond 80% uses the value in the 80% cell?

So, obviously there are other factor that contribute to the load figure I see in the log exceeding what I would expect to see. Can someone please explain why that is? I'm new to tuning, and trying to learn, so please accept my apologies and thank you for your patience.

Anyhow, I would like to eliminate the boost spike, and I think that if I lower lower the BTEL tables #1A and #2 values between 3000-4000rpm for 70 and 80 throttle I should be seeing less boost at that rpm range when flooring the car. Am I correct in this assumption? Is there a better way to fix a boost spike?

Thanks again for your time and expert advice. I've included 3rd gear and 4th gear logs, (had to .zip file them, as it looks as though we're not allowed to upload .csv files) in case you'd like to take a look at what I'm talking about...


*****EDIT*****

After reading some more how boost control works, I went ahead and modified the following parameters in the map tables:

Reactive solenoid WGDC Correction Interval (low/high gear) - from 7 to 3
Passive solenoid base WGDC map 1A and 2 - lowered values b/w 3000-4000 rpm by ~5%
Reactive solenoid base WGDC map 1a and 2 - lowered values b/w 3000-4000 rpm/70-80% throttle by ~5%

Was this the correct approach? Please, if someone can confirm that what I've changed is a good way to go about reducing boost spike b/w 3000-4000 rpm, i would really appreciate it. Thank you.

- Tony