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 ---

 

Dude, where is your build journal. I need to follow your wins/losses on your R56. Wife will not let me sell mine long term for another car

 

Take a look at the attachment in post #1. Title changed but content is the same, with additions.

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.

 

Oh OK i thought you had a online post somewhere. Thanks for the attachment.

 

On page 8 you note adding a voltage limiter to BOTH MAP sensors. As far as I know there is only one in the intake manifold. What other one are you talking about?

 

On the pipe that goes from the IC back to the manifold. The other is at the manifold

 

Right on ThumperMCS, this other one is a dual sensor --- it too measures pressure, and the 4th wire is a temperature sensor. This temp sensor gets a lot of attention when adding a WMI system, but that's a different subject. I have no idea why there's two MAP sensors. It's possible that only one of them needs the FCD, I didn't try to isolate which one, just went "whole hog".

 

I always thought that was intake temp but had no idea it also measured pressure. That is really weird.

 

Be careful with the FCD/BCD, after the limit is reached all additional pressure is technically unmetered, you would need a really relaxed tune to keep things on the safe side since the ECU will never know if boost happens to rise beyond the amount you tuned for.

 

Very true! My original search found a couple others that had "protection" from this overboost situation. There was a second adjustment that bypassed the zener diode effect. I elected to not use them because they interrupted the OEM signal, rather than just limiting it.

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.

 

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.

 

Hi there,

Currently having this issue, and trying to defeat it on the software.
Did someone manage to defeat this limit via software ?

 

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.