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Thread: Xede as Boost Control

  1. Default Xede as Boost Control

    A quick question.

    My car was on the dyno over the past 2 days getting tuned and is having issues controlling boost.

    I have the Xede fitted but boost is still spiking and the tuner can not get it under control. This is the second tuner that has struggled with boost spike / cut on my car.

    Should I be looking at a boost controller? What should we be checking to correct this issue?
    Thanks.

  2. #2

    Default

    I had an xede on my last mps too mate.

    As far as I know, there is no way to stop that boost spike, I take it you mean the one around 2500-3500rpm.

    Just about every dyno I have seen of an mps has a boost spike.

  3. #3
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    Default

    More than likely spiking due to your ETS TMIC, they are a bugger for spiking, do you have an aftermarket TIP as well, if so I imagine this would also contribute to the issue, anyway a boost controller will probably do less than you can using the Xede software, what sort of spikes are you seeing?

  4. Default

    I didn't ask what it was getting too. But I would assume out above 22psi.

    It is more a fact that the boost is unstable. It doesn't hit 18 psi and stay there. It will get to 18 then slowly creep to 19 then spike or drop off.

    My car has always had issues with boost spike / cut. Having it with the ETS is nothing new. It had a partial tune done in February and hit 225kw with the ETS and CES SRI but now it is down to 211kw with boost issues.

  5. #5
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    Default

    As discussed previously, spike and creep are 2 different animals, a 22 psi spike isnt the end of the world, the boost creep you are experiencing is most likely attributed to your divorced DP.

  6. Default

    Understood, but it is boost cutting and I want it solved rather than ignoring it and hoping it goes away.

    Obviously I am also trying to save some money by getting an Xede based fix instead of having too buy and fit a boost controller.

  7. #7
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    Default

    Boost cutting with the Xede in place, that sounds odd, usually the Xede can be tuned to fool the ECU's boost ceiling, what sort of scenario is inducing these cuts, is it high revs / boost, or quick acceleration from the lower rev range.

  8. Default

    I don't have the graph on me but I believe the cut comes in below 4000rpm.

    If you look at my old graph boost is at 18psi from about 4260rpm now it is up to 18psi from around 3000rpm (from memory, it may not be that fast but it is real fast)



    It may be the CPE engine mount but the wheels are spinning in 3rd again at about 80km/h
    Last edited by Crusher_13; 14-04-2010 at 12:56 PM.

  9. Default

    The factory MPS boost spikes slightly due to the boost coming on quickly, it boosts at a rate relative to expected torque. I don't think this is the issue you are describing. We would require to see your vehicle's current boost graph to provide assistance.

    Leah @ CT

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    Default

    You might be experiencing a fuel cut, not a boost cut as such, maybe your tuner should try and dial a bit of boost out down low to avoid this, although if your on 100% wastegate duty cycle and still having boost control issues, you may need to look at other alternatives, a boost controller wont do any more than the Xede in these terms.
    My understanding is that the Xede can scale the boost cut higher than your peak boost and the wastegate solenoid adjustment controls the boost, fuelling is then adjusted to suit the new boost profile.
    Nearly all men can stand adversity. But if you want to test a man's character - give him power.
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  11. Default

    Thanks guys.

    I need to drop by my tuner and will get the dyno sheet from him by the end of the week.

  12. #12

    Default

    Your AFR's are very interesting, never seen anything like it.

    You are running quite lean up to the point where the boost creeps up, then it leans right out in that area, then riches right up after it.

    Are you sure the guys you are using having tuned your car right, that seems very odd.

    Have you added any mods since getting the car tuned?

  13. Default

    Quote Originally Posted by LittleredMPS View Post
    Your AFR's are very interesting, never seen anything like it.

    You are running quite lean up to the point where the boost creeps up, then it leans right out in that area, then riches right up after it.

    Are you sure the guys you are using having tuned your car right, that seems very odd.

    Have you added any mods since getting the car tuned?
    Thats due to the continuous issues with boost.

    The actual AFR never hits 12. it peaks at something like 11.8.

    The tuners have said it is all down to the boost. Are you saying I should be looking at someone else to tune my car? Leah, your opinion on this?

    Then the season differences between Canberra and sydney would cause issues. The coldest day in Sydney over winter is the warmest day here...
    Last edited by Crusher_13; 14-04-2010 at 06:49 PM.

  14. #14

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    I had mine tuned by Chiptorque then drove it back to Lithgow (1000m alt).

    Never had any of those issues.

    My AFR's were more like a sudden drop from around 12.5ish at low revs to more like 11's around where the boost came up.

    I was also only running 17psi boost, but the initial spike around 2500-3500 was into the 19's.

    I also noticed that my AFR ran down closer to 10.5 as I reached high revs, presumably to reduce detonation with the higher boost.

    I never had that lean out that you do around the 4k rpm point though.
    MPS is gone. Ghey Trail enabled....Not Happy. MPS 6 to come

  15. Default

    Quote Originally Posted by LittleredMPS View Post
    I had mine tuned by Chiptorque then drove it back to Lithgow (1000m alt).

    Never had any of those issues.

    My AFR's were more like a sudden drop from around 12.5ish at low revs to more like 11's around where the boost came up.

    I was also only running 17psi boost, but the initial spike around 2500-3500 was into the 19's.

    I also noticed that my AFR ran down closer to 10.5 as I reached high revs, presumably to reduce detonation with the higher boost.

    I never had that lean out that you do around the 4k rpm point though.
    As much as I love the feedback I hate it!

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  16. Default

    A further question. Our ECU's are learning ECU's.

    Would a ECU reset have caused these issues?

    i.e. it would have reset to its factory specific settings so the Xede would have worked on these old settings and not the learnt parameters?

    Yes? No?
    Last edited by Crusher_13; 15-04-2010 at 12:17 PM.

  17. #17

    Default

    Quote Originally Posted by Crusher_13 View Post
    A further question. Our ECU's are learning ECU's.

    Would a ECU reset have caused these issues?

    i.e. it would have reset to its factory specific settings so the Xede would have worked on these old settings and not the learnt parameters?

    Yes? No?
    Yes and no.

    The XEDE only intercepts what it sees, It has no memory of what the ECU has done previously.

    I don't know which is "open" and which is "closed" loop, but, here goes.

    The ECU learns in "open" loop only, i.e. when you use anything under say 80% throttle (not 100% sure on exact % of throttle), the XEDE intercepts these parameters. In "closed" loop the ECU reverts to the factory settings. With the flash tune setup, the ECU still learns as such and still reverts to the new factory tune. The XEDE will intercept all tunes.

    Set the DashHawk up to read Boost, AFR, fuel pressure and LTFT (long term fuel trims) and watch when the signals change. TheLTFT will revert to 0.00 when the ECU changes from "open" to "closed" loop or vice-versa. You should be able to see what changes.

    If it is boosting into 19psi (on the DashHawk)for more than a few seconds, the ECU cuts power. I have a boost gauge and DashHawk that show 4psi difference. The DashHawk will show what the ECU sees, the boost gauge shows exactly whats happening. The fuel cut show other changes.
    Achievements
    2009 Jamboree Street Compact Winner
    Aust. Quickest and Fastest MPS
    12.3 seconds @ 111Mph.
    Proven over the Qtr mile

    Another Mazda 3 MPS - Almost fully bolted - Waiting for a turbo upgrade - The weekend hack.
    Toyota Yaris - Coilovers, rollcage, raceseats, harnesses, 18s - Also waiting for a turbo upgrade.
    2011 AWD Territory - White and Slightly lowered on 22s - The tow car.
    2011 RWD Territory - Black on black and slammed on 22s - The family transporter.

  18. Default

    Xede intercepts the ECU's signal and then lies to the ECU about what is going on. Correct?

    If this is done via equations based on the original map, would the equations not be wrong? Thus lean AFR's and excess boost?

    when changing your map its just like unhooking the battery for the ecu (this is in relation to reflashing a car with a different AP Map). it has to start all over. i dont think you need to stay out of WOT though. thats how the car learns. the car has several levels fof fuel trims that are based on throttle position. if you dont go WOT it wont learn its fuel trims for it.
    the LT trims show what the ECU has learned already. if they stay steady that means your ecu is doing a good job ! its when the short terms trims move all over the place that you have issues .
    These are taken from this short thread at msprotege.com

    I also found something from you 2XS. You said the car learns in "closed".

    They do, yes, but, from a visual point, I think the ECU only learns to a certain degree.

    I've noticed on the DashHawk that when I go past a certain part of the throttle, the signals/readings that are on the DH then change. It goes from closed loop (learning) to open loop (what has been flash tuned) and all the learning that has been done, is bypassed while the ECU only uses the base tune.
    If my car went from engine mount being fit and battery disconnected to the dyno it would not of had the chance to learn how much of everything is available. Thus the ECU would have gone directly to what Mazda last flashed the car with. If Xede relies on what it receives from the ECU it would have been receiving false information. It would have recieved the message that at 100% WOT (a) air is available when infact (b) was available. Thus causing issues.

    Does this work?

    Leah? 2XS?

  19. #19

    Default

    Quote Originally Posted by Crusher_13 View Post
    Xede intercepts the ECU's signal and then lies to the ECU about what is going on. Correct?

    If this is done via equations based on the original map, would the equations not be wrong? Thus lean AFR's and excess boost?
    True





    These are taken from this short thread at msprotege.com

    I also found something from you 2XS. You said the car learns in "closed".
    I may have been wrong in this instance, I don't remember which way it is for sure.




    If my car went from engine mount being fit and battery disconnected to the dyno it would not of had the chance to learn how much of everything is available. Thus the ECU would have gone directly to what Mazda last flashed the car with. If Xede relies on what it receives from the ECU it would have been receiving false information. It would have recieved the message that at 100% WOT (a) air is available when infact (b) was available. Thus causing issues.

    Does this work?

    Leah? 2XS?
    The ECU always uses the base map from Mazda (or the new flash tune) to get it's own trims etc. It learns from this base tune to alter it's own "variation" into the tune. The XEDE only intercepts these signals.

    The XEDE is like a person sitting on a wall. The ECU is on 1 side, the engine/signals on the other.

    The person sees the engine/signals "Figure A", intercepts them and then relays them to the ECU, which inturn produces "figure A1". The same signal only slightly different.

    Whether the car has had time to learn the new tune before tuning shouldn't matter one bit. It always runs from the ECU base tune.

    You could try removing mods until you find the culprit. It may be a combination of 1 or 2 mods not working together. Start with the easiest mods first. If in doubt, rip it out.

    ---------- Post added at 05:38 AM ---------- Previous post was at 05:34 AM ----------

    Maybe get your tuner to give Chiptorque a call.
    Achievements
    2009 Jamboree Street Compact Winner
    Aust. Quickest and Fastest MPS
    12.3 seconds @ 111Mph.
    Proven over the Qtr mile

    Another Mazda 3 MPS - Almost fully bolted - Waiting for a turbo upgrade - The weekend hack.
    Toyota Yaris - Coilovers, rollcage, raceseats, harnesses, 18s - Also waiting for a turbo upgrade.
    2011 AWD Territory - White and Slightly lowered on 22s - The tow car.
    2011 RWD Territory - Black on black and slammed on 22s - The family transporter.

  20. Default

    The reason I thought the issue could be the ECU reset is simple. It is the only thing that changed between 225kw and no boost issues to 211kw and boost issues.

    Hmmm. I am sure it can get sorted.

    Any issues with the flash and boost pressures 2XS?

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