Drivetrain R56 MCS 22psi Boost Limit Can Be Defeated
#1
R56 MCS 22psi Boost Limit Can Be Defeated
Here’s a summary of my latest journal update. It’s the last update under “November 2012” --- starting on page 8. The latest version journal is attached. Lotsa details on installation and adjustment - useful for those who want to try it.
Went online to look for a piece of equipment to limit the ECU boost signal. Found out it goes by a couple different names --- Fuel Cut Defender (FCD) or Boost Cut Defender. A guy on e-bay, using the name “PocketRocket”, is selling his home-made version. His product is well described, it functions as I expect a voltage limiter (zener diode) to function, and the price was right. I recommend it highly for the R56.
Bottom line is, the 22psi ECU limit for the R56 MCS can be defeated. The concern is, you gotta have the turbo to provide the extra boost. Then you gotta find a tuner with the expertise to make it all work. I haven’t yet scheduled another dyno tune, so I don’t know the boost limits, if any. And with no bottom end engine upgrades, I’ll probably set my limits pretty low. So far, I’ve had the boost up to about 25psi, using my ProSport gauge, with no CEL (AP datalog only records boost allowed by the FCD). Until I get on a dyno, the MBC is dialed back to 22psi --- the original dyno tune is for 17 - 20psi.
I did a couple quick forum searches on the hardware, but couldn’t find any other successful installations for a Mini Cooper. Hope this info is useful to someone else ---
Went online to look for a piece of equipment to limit the ECU boost signal. Found out it goes by a couple different names --- Fuel Cut Defender (FCD) or Boost Cut Defender. A guy on e-bay, using the name “PocketRocket”, is selling his home-made version. His product is well described, it functions as I expect a voltage limiter (zener diode) to function, and the price was right. I recommend it highly for the R56.
Bottom line is, the 22psi ECU limit for the R56 MCS can be defeated. The concern is, you gotta have the turbo to provide the extra boost. Then you gotta find a tuner with the expertise to make it all work. I haven’t yet scheduled another dyno tune, so I don’t know the boost limits, if any. And with no bottom end engine upgrades, I’ll probably set my limits pretty low. So far, I’ve had the boost up to about 25psi, using my ProSport gauge, with no CEL (AP datalog only records boost allowed by the FCD). Until I get on a dyno, the MBC is dialed back to 22psi --- the original dyno tune is for 17 - 20psi.
I did a couple quick forum searches on the hardware, but couldn’t find any other successful installations for a Mini Cooper. Hope this info is useful to someone else ---
#3
My experience with forums was nil when my project started - not much better since then. Just finished reading your signature link --- awesome write-up. My journal is no comparison! Northern NV has a very small Mini enthusiast community. Nobody here to lean on / learn from, but we're growing.
Gonna be at least one more update - working with Alta for another tune, either remote AP or his dyno, TBD.
Last edited by oldbrokenwind; 11-20-2012 at 04:01 PM. Reason: Clarification
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So far, my tune is relatively "relaxed", compared to an RMW tune. Probably why my R56 is still running. Also, I seldom "get on it" --- Northern NV is a pretty tame community. I'm currently working on getting a tune to accommodate the extra boost. Same people that did my last tune, using the AccessPort. Until then, boost is dialed down to about 22psi.
#11
My AP data logs now show boost "spikes" up to the Manual Boost Controller setting, currently about 22psi, as measured on my external boost gauge, then the AP readings settle down to the FCD settings. This "spike" lasts for about ½ minute.
Does anyone know how the boost reading, at the AP connector, is calculated? There must be some other boost input to the ECU, because I've got the 2 MAP sensor outputs limited with the FCD zener diodes.
Before the FCD install, this MBC setting would cause an overboost cel, WGDC readings of 0.0%, and other errors. At 25psi there are no errors --- even this “spike” is being tolerated by the ECU. Performance increase is noticeable, but without a tune for the extra boost, I’m not going any higher with it --- FEAR!
I’m still trying different ways to lose the “spike”, but no progress yet. A little “theory of operation” would be really helpful.
Does anyone know how the boost reading, at the AP connector, is calculated? There must be some other boost input to the ECU, because I've got the 2 MAP sensor outputs limited with the FCD zener diodes.
Before the FCD install, this MBC setting would cause an overboost cel, WGDC readings of 0.0%, and other errors. At 25psi there are no errors --- even this “spike” is being tolerated by the ECU. Performance increase is noticeable, but without a tune for the extra boost, I’m not going any higher with it --- FEAR!
I’m still trying different ways to lose the “spike”, but no progress yet. A little “theory of operation” would be really helpful.
#13
Almost all tuners can now defeat this 22PSI limit. My original custom AP tune had it up to 30, but I was told to keep it at about 25 max. Both Manic and RPM defeat it and probably most others do too.
Ludopo, I responded to your PM and suggested you look at my other threads. The most recent thread is https://www.northamericanmotoring.co...ec-2018-a.html and it has links to earlier threads. I completely forgot about this thread.
Ludopo, I responded to your PM and suggested you look at my other threads. The most recent thread is https://www.northamericanmotoring.co...ec-2018-a.html and it has links to earlier threads. I completely forgot about this thread.
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