Hey everyone, I'm trying to come up with possibilities which may be causing my MINI to lose boost occasionally . It's an 07 MCS manual. Mods are as follows:
Alta Accessport stage 2 Tune
K&N CAI
Riss Racing Catless DP
Invidia Q300 Exhaust
Alta Hotside boost tubes and BOV spring

I usually find that it most commonly drops boost at lower RPMs when I gun it. I've asked ALTA about this issue, and they seemed to have no knowledge on this subject. They made a custom Map tune for me, and it worked for about a day until it continued to drop boost. I thought the upgraded hot side boost tube would fix the issue, but still no luck. Let me know any ideas.
- Dan

 

Tighten up your clamps, make sure you have no air leaks.

Dave

 

Would an exhaust leak cause loss of boost? Also, which clamps would I be sure to tighten? I haven't done very much engine work, it's been dropping boost since before the hotside.
- Dan

 

+1, check all clamps, but also the BOV spring. If thats flukey, your boost blows right out the atmosphere and goodbye HP. Stock BOV otherwise?

 

An exhaust leak would not contribute significantly to a boost loss issue. Even if you took the whole exhaust off from the turbo downpipe, the turbo will still produce boost.

The most common cause of boost loss is a leaky combustion air system. Check all clamps, hoses, & other connections from the turbo intake all the way to the intake manifold. If there are no leaks there you could have a diverter valve or wastegate issue.

 

Seek nowhere else than your tune...
This problem has been discussed in extend in numerous threads.
It is the common boostcut issue at 22psi. Once the ECU reads 22 it instantly drops the boost to 5psi. The tune is to blame...
Try Evolve's tune. They are the only ones offering boostcut free tunes.
Been there. Done that.

 

I mean, i'll try checking the clamps, but I haven't heard of many cases of the alta accessport doing this.

 

Stock BOV, and it was dropping boost before I did the BOV spring. I checked the valve, and everything looks fine.

 

Which ones generally? For the most part, I've been checking my hoses and such, I'm really not sure what to do at this point.

 

I also have a 2007 MCS with the same issue. I have been in contact with alta on the issue and they wrote a tune for my car that seemed better until the ambient temp exceeded 50 degrees F. It seems like these early ECUs have more issues than the newer ones. Mine is a GB02B ECU.

[QUOTE=ThePenl;3532963]Seek nowhere else than your tune...

ThePenl,
Is the Access port useless for those of us whom have the early R56. Please forgive my Ignorance but is Evolve someone who makes a tune for the Access port or is there a whole new tuner to buy?

 

I don't think this boost cut issue has anything to do with the ECU's production year. It is surely temperature related, cause the ECU is trying to compensate for higher IAT with higher boost, in order to obtain its load target! So, when ambient rises, the 22psi limit is being reached and consequently boost cuts.
I have been experiencing these boost cuts with a local Greek tune I had for two years. Winter was not a problem, no boost cuts occured, but when the ambient rose above a certain degree, then it would cut boost non stop.

Three months ago I ordered the Evolve-R remote tuning tool, which is practically an OBD to USB cable. You read your original stock file with the Evolve Windows based software, save it to your hard disk, e-mail it to Evolve and they get back to you with the tuned file. Read or write to ECU lasts no more than 60seconds. The most important about their tunes is that they are BOOSTCUT FREE...at last! You don't have to worry about hitting the boost cut limit of 22psi. Even if you reach it, it won't cut the boost to 5psi. Apart from that, their tune has correct AFR and EGT are lower than before. Overall it is a very good tune and the driveability of the car is second none. You won't have to worry about the boost being cut every time you are trying to overtake someone.

Evolve is an individual UK tuner and offers tunes worldwide. They also have a US dealership. Find further details here: http://www.evolvetuning.us/

Personally I never used the accessport cause my car is European. From testimonies of US cars and all over the world, I can safely conclude that these boost cut issues have been there right from the start. No one could do anything about it over the past 3 years, and now Evolve has addressed the issue. As far as I am concerned they won my trust and I am very happy with their boostcut free tune. It runs smooth, very strong, and problem-free.

 

Thank you for the link and explanation. I just wish that it wasn't another $1,000 for the tuner. At least that is what I could find on their web site for a price (BMW) though I couldn't find the Mini price. I would be game to blow the cash but I am building a new house so my toys must play second fiddle for a few years. Thank you again for the info. It is nice to have reassurance that the issue may not be my car because if that is the case I have been chasing nonexistent problems for the last year trying to make the access port tuner work for my car.

 

I have been experiencing the same issue. I have an 07 with the same GB02B ECU and my list of mods include: Alta intake, Alta hard intake pipe, Alta Downpipe, Alta Exhaust, Alta uprated BOV spring, Alta FMIC, Alta Accessport. I had hoped that buying everything Alta would lower my risk of issues due to Alta not making the maps for mods from other companies.

This seems to be a temperature issue, I have tried stage 1 w/ and w/o fmic, stage 2 w/ and w/o FMIC, and stage 3 along with a couple custom maps from Jeff at Alta. The addition of the FMIC that I installed 2 weeks ago did help but did not remedy the issue. I noticed that if I drove at night, I never got an boost cut, but as soon as I drove in the day when temperatures raised above 70 degrees, the car would spike the boost to 22 and then cut down to 5psi. I've tried every remedy and nothing has worked. I have noticed that before I had the FMIC, it would cut boost in almost every gear and in both stage 1 and 2. After the FMIC, stage 3 only cuts boost during the day and only if I start under the torque curve (ie 6th gear at 50mph at about 2000rpm) and push the throttle to the floor, the boost would "surge" (which I can only explain the experience like a car with a bad clutch-pressing the throttle increases sound but accelerates the exact same no matter the amount of throttle applied)- the boost would increase but it felt like it wasn't reaching the motor (or the turbo was slipping) to increase hp and thus increase acceleration. The boost continues to surge up to 22psi then the ECU cuts the boost to 5psi. I can say that the FMIC has helped and if I accelerate from a stand still during the day, I experience no boost cut, and the boost jumps to 17psi and the car pulls super hard and strong with no "surge" in 1st, 2nd, and 3rd gear, but on the freeway I still experience it in 4th 5th and 6th.

A couple of remedies that I have wondered about are:

Can we swap the thermostat to open at a lower temp, so that the car runs cooler?
Can we look at the sensor that reads Ambient air temp?

Since the FMIC helped to lower the intake temp, and this issue shows its ugly face in the summer, is there maybe something that should be looked at in the tune- ie doing something similar to what the Accessport does to get rid of the CEL that the ECU reads from an aftermarket Downpipe- to the sensor that reads the intake temp/ambient temp (MAP sensor)?

If we could fool the sensor to think its 69 degrees out all the time, we may loose a little HP when its 90 degrees out due to the air being less dense and the ecu won't ask for more boost to compensate, but at least we will be able to pass a semi on the freeway without looking dumb when we pull out and suddenly can't accelerate faster than the semi due to having no boost and roughly 130hp, and having to switch back into the slow lane and wave at the minivan that we just cut off and wait for a larger gap to pull out into!!!


On a side note, my friend has a 20th anniversary VW GTI with a stage 2+ tune from APR, he had a similar issue of boost "surging" up to a certain psi, and then it would cut the boost, though I can't say that it was exactly like our issue, I can say that he had to buy an upgraded wastegate actuator from Forge. From what I understand, its basically a boost controller that limits the boost to 17psi no matter what the ECU asks for. With the ECU asking to get more boost than usual due to it being hot outside and the air is less dense than if it was cold which is what the turbo is supposed to do (compress air to make it more dense), if we did one of these wastegate actuators or maybe a mechanical boost controller, would it keep the ECU from spiking the boost and in-turn keep the boost at 17psi versus the (I'm only guessing) engine damaging 22psi that it spikes to?

Also, I wonder just how much damage this boost surge up to 22psi is doing to our motors. I can't imagine stock internals on these cars can handle the hp 22psi of boost that it's subjected to.

Hey guys, I just want to thank any input or incite on the subject, and hopefully us talking about this issue will encourage people/tuning companies to try to find a cure. I know it's been discussed before and I have spent hours on NAM/other Mini forums looking for an answer but all threads have seemed to have become stagnant for almost a year now and I'm hoping that reigniting the conversation will create results, all we can do is keep trying new things, and i sure can't afford to try everything, I've already bought a FMIC, BOV spring, and Intake to try to fix it (though I may have also had an alternative motive), but hopefully through other people's experiences we can check off what doesn't work and get some input on things that haven't been tried before.

Thanks again,
Bernie

 

poodey,
I have a turbo back obx catless exhaust, Forge FMIC, custom cold air intake (See Picture), Samco silicone turbo pipe kit that eliminates the preintercooler resonator and a straight pipe where the noise maker was, Mechanical diaphragm BOV, Saikou Michi double oil catch can with both PCV tubes functional, NM torque insert, and have updated the valve cover, installed new plugs, cleaned the intake and valves, changed the thermostat housing, and checked for intake leaks more times than I have driven the car it seems.
I don't claim to know more than anyone else, I can only state what I have noted on my car so please take what I say for what is worth. Hopefully helpful info but who knows.
From what I can gather from the datalogs I have acquired I think that the speed of the wastegate opening, or its limit is wrong. It would be funny if it is just an equation entered in wrong on some programing calculator that is causing all these boost cut issues. I too noticed that I had fewer cuts when I installed my intercooler but they do still occur. In all fairness I have not given Alta a chance to write a new custom map with the most current mods I.E. the exhaust and intercooler. I had some issues with my oxygen sensors after the exhaust I am still working on. I will say they have some of the best customer service of any companies I have dealt with in a while.

 

I agree fully- the guys at ALTA have been awesome. I don't want to discourage anyone from the Accessport, it is hands down the best investment I've made since purchasing the Mini.

So far I can check off the following as not a cure:

Mechanical BOV- was actually gonna be my next attempt. I was going to use the internals from an A3, or the Alta mechanical BOV that they are testing right now and will be available soon. But from what I understand, a bad BOV would cause underboosting where the boost never reaches the 17psi requested.

Noisemaker Delete- no effect. I thought maybe this stupid chamber causes a drop in pressure right before the intake manifold.

You said you changed the thermostat housing, was this an improvement? Have you noticed a decrease in engine temp after? I would think that if the motor runs cooler, the engine bay may be slightly cooler equalling slightly lower intake temp which I guess would only help by 2-3 degrees so if the issue happens at any temp over 70 now it would only happen above 73?

Front Mount Intercooler- Not a solution, but helps. It's good to see that I wasn't imagining this improvement.

You had mentioned it could be an issue with the wastegate, from what I understand, the wastegate isn't an external one so it cannot be removed/upgraded. I keep noticing a trend of temperature, is this possibly an issue of the ECU requests more boost when its hot outside let's say 19psi instead of the normal 17, but the wastegate can't hold pressure higher than 17 so it opens slightly, thus allowing the boost to escape, and when the ECU sees that 19psi didn't change anything so it tries a higher psi ie 20-21 but the wastegate obviously has the same issue and the ECU tries an even higher psi ie 22 and then the ECU cuts the boost? This would explain that weird "surge" that I notice every time I encounter the boost cut, it feels like I'm running 10psi even though my boost gauge says it's 15-16-17-18-19-20-21-22- then 5psi. The boost keeps creeping up but no increase in acceleration, but in lower gears and when the stars all align, I can go full throttle and that boost gauge reads 17psi and doesn't move an inch while the acceleration is smooth and strong, like what I thought a stage 3 turbo car with money invested is supposed to feel like.

This is my first turbo car so this is relatively new to me and I don't understand how these parts work.

I wonder if it is easier to remedy the situation by fooling the sensor or by fixing the wastegate. If the wastegate is removable, has anyone tried a different one or upgrading somehow? Or could the sensor be moved somewhere else to read a different temperature or be fixed by sending the ECU a constant voltage that would be equivalent to like 65 degrees or something?

 

I changed the thermostat housing because the seal around the sensor was seeping. I could have just resealed the sensor but I know these are an issue so I opted to play it safe and replace the housing. The only change I noticed is that my in line temp gauge actuates smoother as opposed to how it would move in steps as the temp rose. I think this is because of a smoother actuating thermostat. These cars acually need the 220F-224F to operate correctly. There is no reason the internal coolant temp would make the blow off symptom occur that I can see.
As for the wastegate. I attached a picture of the wastegate view from the exhaust down pipe opening. There would be no way to replace it as it is cast into the turbo housing. The wastegade "door" is the cicular item to the left of the turbine wheel. the wasgegate "door" is connected to an arm that is driven by a diaphragm actuator. This diaphragm is moved with vacuum from an accumulator tank held at -19-25inhg. The vacuum is maintained by the brake vacuum pump on the end of the exhaust cam. Between the diaphragm and the vacuum accumulator tank there is an ECU controlled variable relay valve. From what I can understand this wastegate is backwards from other industry standards. Normally a wastegate is sprung closed and when less boost is needed a diaphragm pushes it open from pressure coming from the compressor side. The wastegate on these cars is spring open and is closed with vacuum.
The ECU gathers data from all the sensors and makes a call on what wastegate opening to apply. The "Leak in the turbo inlet" scenario makes sense in that the turbo is getting an alternate supply of air not seen by the Mass air flow meter so the needed wastegate position would create more boost than calculated. I would love it if this wre the issue but I am absolutely 1 Million percent positive that there are no leaks. I think the wategate system is working correctly but the program entered into the ecu "Map" doesn't or can't account for the speed of boost build at + 50F or in your case 70F ambient temperatures. My theory is that the wastegate can't actuate quick enough in those conditions.
These are just my understandings and theories if I am wrong about something PLEASE correct me. I would rather know the way things actually are. I have seen way too many "Too Proud" people screw things up because they are unwilling to listen.

 

Wow, this is the kind of conversation that could cause a breakthrough!!! Thanks, this all makes a little more sense than it did before. Reverse actuated non removable wastegate- anyone else using this style in the industry? BMW I'm guessing, but is anyone modifying them like we are that may have already ran into and fixed this issue?

So I take it an inline boost controller would have no effect as well due to the ECU having multiple sensors that would adjust the boost later in the system.

So I guess it goes back to the mapping. When I talked to Jeff at alta, he had mentioned that there are certain maps in the ecu that they don't mess with. So could it be that this system of checks that the ECU has programmed and also the curve that the ECU has for higher temperature is one of those maps the accessport tunes don't modify. I wonder if it is possible for them to crack the code/do some testing with modifying some of these other maps to see if it has an effect.

Any Guinea pigs?
I would be up for testing this theory, I'm just worried of the damage/life shortening effect that this surge up to 22 psi could be doing to my motor. Everything comes down to stress- more hp/boost=more stress. More stress=more wear. More wear=shortened engine lifetime/damage. Just want to make sure everyone gets to enjoy the extra power that they want without any consequences.

Thanks again for all your input, this is the closest I've seen to an actual explanation for the boost cut I've seen so far.

 

Also reading back over your last post youamen tuned that there is a brake vacuum pump on the end of the cam. Is it possible there could be a leak on that vacuum line that goes from the vacuum pump? Would this leak cause the vacuum to not be enough to hold the wastegate shut and would cause it to leak boost causing the surge? Or could the plunger in the vacuum pump be old and act like a bad brake master cylinder causing the vacuum to not reach the correct amount which would not hold the wastegate shut? Has anyone tried replacing these vacuum pumps? With our cars being 6 years old this could cause the issue.

 

Poodey, reread post #6 from thePenl before spending crazy money and time. I have friends with the same boost cut from your tune.

 

A standard wastegate controller would not work. I have read some posts right after I got my car about the standard controller and it was stated that the ECU would freak out. I think that the wastegate curve or opening rate needs to be dependent on the throttle opening vs engine RPM. For example if the engine were at 2,000rpm and WOT is needed the wastegate shouldn't go to the same position that it does as if the RPM was at 4,000rpm. Instead of going to 90% closed it should start at (just to throw a number out) 75% and step up as needed to maintain proper PSI. If the engine needs 100cfm at 4,000rpm to maintain 17psi it doesn't need 100cfm at 2,000rpm for the same pressure. The thing that sucks is all this is out the window when air density changes so the rate scale needs to be also dependent on temperature and barometric pressure.
I have removed my brake vacuum pump and replaced it with an electronic pump. There was no change in functionality I just posted a new thread called "brake vacuum pump delete" A weaker vacuum would create less boost because it would not be able to close the wastegate. My car has never had a problem closing the wastegate to make more boost. The column labeled WGDC stands for wastegate duty cycle. If I understand correctly this column is in percent closed. Most of the time when my car exceeds the boost target the wastegate only pulls back to 50% where it would make sense to pull back sooner in anticipation of creep and farther to maintain the target boost.

 

guys guys guys.....

This is a very well known issue that many have dealt with for quite some time now. Please listen to ThePenl...he knows his stuff

This is purely an ECU tune related issue....not mechanical.

 

I really don't want to have to spend another $1000 on a new device, I'm looking to see if we can remedy the issue using the accessport I already own. Hopefully someday I can enjoy stage 3 on a nice summer day without an issue.

 

thePenl has a great option but unfortunately I have already spent lots of money on my access port and would like to see if I can make it work before spending another $1,000 on a new tuning device and software. I wish I had the extra cash to spend to have every option but I don't. On this subject I hope the guys at Evolve are not disabling the built in ECU safety feature just to say they don't have boost cuts. I wouldn't think they would as the seem to be a very reputable company.

Has anyone used the Evolve-R tune and watched a boost gauge to make sure the boost levels stay in a safe range say under 20psi?

 

Yea you can.....you can get it re-tuned, utilizing less aggressive load targets. You boost will be lower and car will not be as quick, but you won't have boost cuts. Stage 3 was un-useable on my 56...

Again, this is not a mechanical issue. And I'd venture to say pretty much any mechanical way you try to "fool" the ECU, you will end up with more frustration than you already have. Been there done that

 

I agree I think that we are just trying to find a way to remedy the access port tune issues. I just hope its not a lost cause and can get it sorted.