oggy Posted December 3, 2016 Report Share Posted December 3, 2016 Hi All,I have a G4+ fury ECU with closed loop boost control setup by my tuner and I'm having a few issues with the boost spiking a bit. Every now and again the boost will spike well past the target, causing the overboost fuel cut. Doesn't happen all the time (in fact it hadn't happened for about the last 4 months, but has started happening agin), but does seem to happen a bit more when the car has a bit more weight in it.Does anyone have any advice as to which settings I should alter to prevent this? I've attached a couple of screenshots below of the boost control settings at the moment. I haven't really played around much with closed loop before, so I'm not really sure what the best place is to start to be honest.I don't mind if it spikes a bit coming on, but this is excessive haha. Cheers,Josh1jz vvtiGTX3076, 0.82 rearturbosmart 50mm external gate.Peak boost target: 234kPaMAP fuel cut: 270kPahttp://i213.photobucket.com/albums/cc145/jposupra/log screenshots/aux output boost.jpghttp://i213.photobucket.com/albums/cc145/jposupra/log screenshots/boost setup.jpghttp://i213.photobucket.com/albums/cc145/jposupra/log screenshots/boost PID setup.jpghttp://i213.photobucket.com/albums/cc145/jposupra/log screenshots/boost target table.jpg http://i213.photobucket.com/albums/cc145/jposupra/log screenshots/wastegate duty cycle table.jpg Quote Link to comment Share on other sites More sharing options...
CamB Posted December 4, 2016 Report Share Posted December 4, 2016 If you have a look at the help file, perhaps your Stage 2 kPA is too low. This would potentially lead to overshoot.I'm no expert but I wouldn't expect the wastegate DC table to look like that, particularly not with the boost target shown (ie, it is relying too heavily on closed loop rather than the underlying DC table), although it may not make much difference in practice.Also the most commonly used MAC boost solenoid is supposed to work better with 20hz or less. You may of course have a different one and 35hz is fine. Quote Link to comment Share on other sites More sharing options...
Scott Posted December 5, 2016 Report Share Posted December 5, 2016 CamB is right when he says that the closed loop boost control system should not be relying too heavily on making changes from the values in the wastegate DC% table. It may be worth saving your base-map to your hard drive, and then turning the boost control system to open loop and see how the performance of the system is.Scott Quote Link to comment Share on other sites More sharing options...
oggy Posted December 5, 2016 Author Report Share Posted December 5, 2016 Thanks for the replies guys, I'll have a play around this weekend hopefully.Yeah, I always save copies of current maps before altering anything Quote Link to comment Share on other sites More sharing options...
Brad Burnett Posted December 5, 2016 Report Share Posted December 5, 2016 As CamB said, Increase your "stage 2 on" value. 20kpa is too low. May need to up that value to more like 40kpa. I have had this specific problem in the past.Also as Cam and scott have said, that Wg table is not tune and solely relying on the closed loop to control. Good luck. Quote Link to comment Share on other sites More sharing options...
90dsmturbo Posted December 11, 2016 Report Share Posted December 11, 2016 Can you post up a log of what the duty cycle output is? This may give us a better idea if the PID control is acting too heavy to make changes to your base table Quote Link to comment Share on other sites More sharing options...
Leiden Posted December 12, 2016 Report Share Posted December 12, 2016 I've found when the wastegate boost source is located at the turbo outlet there can be spiking issues when trying to hold the wastegate closed until closer to the target, I moved the pressure source to just before the throttle body and this sorted the problem and made it easier to tune the wastegate numbers. Quote Link to comment Share on other sites More sharing options...
oggy Posted December 12, 2016 Author Report Share Posted December 12, 2016 had a play around on the weekend.Adjusted the stage 2 on value to 40kpaI couldn't see the MAC number on the boost solenoid without pulling it out so I couldn't confirm preferred frequency - I lowered it to 20hz anyway, as it is likely a common solenoid.Then I adjusted the duty cycle table whilst test driving.I need to do some more testing and logging, but I'm pretty happy with it so far, boost looks really stable.From here I think I'll pop it into open loop and check/fine tune the duty cycle table, then I may have a play around with trying bring it on a bit harder/earlier thanks for all the responses, the help is much appreciated! Quote Link to comment Share on other sites More sharing options...
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