PI controller pro's & Con's comparison: JB4 PI vs split 6

Discussion in 'N54' started by TurboMike, Dec 20, 2016.

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  1. TurboMike

    TurboMike Corporal

    Comparison of how the two products perform and the different features each has.
     
  2. damonp335i

    damonp335i New Member

    5
    Still haven't bought either controller. Leaning towards the JB4 BMS PI controller.. apparently one of the issues with the regular AIC6 is that it can continue to spray when the DI side stops dumping fuel (only for a millisecond) but the BMS controller allegedly stops that from happening which can avoid engine damage or backfires, etc. Just hearsay - I've never ran either but I will be pulling the trigger on one of the two in the very near future. One drawback is that you can't pull logs or make changes from the BMS controller where you can with the AIC6. It seems like there is no 100% "safe" PI controller, but out of all the sub-par options, the BMS controller seems that it could be the safest/most user friendly. I'm in for opinions and feedback also.
     
  3. Joe

    Joe Specialist

    Neither, I use AEM EMS4. Wiring was a nightmare, but it's been solid. I use it to control both PI and my secondary LPFP (Stage 3+). It uses a 5bar AEM MAP sensor for boost reference and also references a few other sensors via ECU splice. To my knowledge, JB4 is incapable of controlling a secondary LPFP. There are others using Haltech to do the same thing.

    AEM gives me batch firing in pairs (1-6,3-4,2-5 if I recall) and a much better tuning platform than the craptastic AIC6 interface. I've gone out of my way to avoid using jb4 and I'm happy with that decision.

    To my knowledge, AEM/Haltech provide safety mechanisms that jb4/aic6 cannot.
     
  4. damonp335i

    damonp335i New Member

    5
    I've never heard of this option.. Is this cheaper in comparison to Haltech?
     
  5. 135Pats

    135Pats Private

    35
    MD
    I think both are rudimentary. Using the AIC but not at all confident in it to be honest.

    "It works" accurately describes where we are with PI right now.
     
  6. damonp335i

    damonp335i New Member

    5
    Very depressing lol. I dont plan to tune my car until April but I don't want to use meth and considering I have easy enough access to e85 I will definitely be purchasing PI. Its just very annoying weighing the pros and cons of all the PI controllers. Right now I am running a flash only map - picking up my car tomorrow.. Pure s2's installed. I have been going back and forth for months with what to use to control the PI. There seems to be no clear cut answer on which setup is truly "the best"
     
  7. Joe

    Joe Specialist

    I think AEM is more expensive by a lot. There wasn't much else out there when I purchased PI aside from standalone AIC6 which was still being tested by most. I would consider the AEM/Haltech solution to be race ready. I think Jake @ MOTIV would probably agree.
     
  8. Dang, using a standalone to control PI seems crazy but if it works, it works.
     
  9. V8bait

    V8bait Corporal

    The haltech is a nice option and the AEM unit. Tuned a guy with a megasquirt as well. They are stand alones but you can find some of them pretty cheap and they can control boost, PI, meth, nitrous, LPFP setups, coffee makers whatever. For JB4 people the JB4 unit is fine.
     
  10. Abacus38

    Abacus38 Corporal

    194
    Tampa/Orlando, FL
    2007 Ti Ag 335i
    Im just going to either hold out for the syvecs or just go with the double pump setup from VTT
     
  11. Flinchy

    Flinchy Private

    I thought the jb4 could control LPFP?

    Or can it only control LPFP OR port injection, not both at once?
     
  12. mt_n54

    mt_n54 Lurker

    13
    I'm running SS AIC6 with flash only and as mentioned above, "it works". I haven't run into any issues, but still feel a little nervous about its capabilities. Same goes for the stage 3 LPFP which is being triggered by a Hobbs switch.

    If you're running these setups, it's best to just let off the throttle if your car isn't running right. Sometimes people keep pushing their cars and end up hurting the motor.
     
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  13. CKI@Motiv

    [email protected] Specialist Vendor

    IMO if your running the AIC you need to be running it with a AEM 3.5 bar (or any other 3.5-4bar) off the manifold for several reasons. When your boosting and shut the throttle for gear change you'll notice the pressure bump in the CP which the TMAP will pick up and the AIC wont know any better and continue injecting fuel causing the backfire most talk about. With a sensor in the manifold it reads vacuum instantly when the throttle closes. Also if you ever over boost and get throttle closure the DeltaP between mani and CP is huge. So essentially your running very rich which can cause the DME to do all sorts of things when it needs to pull a large amount of fuel quickly. Shifting and throttle onset have improved greatly with no back fire or OL post shift. You obviously have to rework the AIC table.
     
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  14. 135Pats

    135Pats Private

    35
    MD
    Sparknotes: DI please...

    The thought of the AIC and Hobbs switch irk me big time. They work, but there's nothing beyond that.
     
  15. mt_n54

    mt_n54 Lurker

    13
    DI is the way to go.. Hopefully somebody can develop a direct replacement HPFP..
     
  16. Abacus38

    Abacus38 Corporal

    194
    Tampa/Orlando, FL
    2007 Ti Ag 335i
    Somebody already has its VTT
     
  17. Bigdaddyaaron

    Bigdaddyaaron Corporal

    Not exactly. They have a pulley to overdrive the pump, but not really a replacement where the pump can move more fuel on it's own. I'm still considering that setup. My only concern is whether or not injectors will be up to the task for long (think daily driver) periods of time.
     
  18. MMP

    MMP Lurker Vendor

    This is not accurate. In the JB4 controller There is a function that monitors fuel trims I believe and maybe another parameter but IT DOES NOT know what PI is doing. If PI shuts a cylinder down due to misfire, the JB4 controller will not shut down that injector to that cylinder and PI will keep spraying. This is the same for ANY PI controller (haltech, AEM, SS, etc) on the market. Only a controller that controls each injector individually as well as PI simultaneously could remedy this issue. Syvecs ECU is currently the only one that has the potential to do this but hasn't been done yet and ECU is $5400.
     
  19. Abacus38

    Abacus38 Corporal

    194
    Tampa/Orlando, FL
    2007 Ti Ag 335i
    From what I've been told the rotary setup that N54 flows the most. Thats why VTT just added another pump to the setup to keep the rail pressure up. If I remember correctly the m3/4/5/6 motors come with two hpfp as well.
     
    Last edited: Dec 25, 2016

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