Bear with me on this as I know it's lengthy.....


Does your tuned R56 overboost? If so I just might have a solution for you.

Having previously owned and worked on a highly boosted ( >22PSIg) Golf TDI, overboost was sometimes an issue. The TDI would actually overboost to 30PSIg. The TDI community uses a simple manual boost control valve to stop the problem. If you're interested in purchasing a boost control valve after reading this post just click the provided link. I've purchased and used two of these to date. You can buy your boost control valve by clicking here






After swapping out my very tired turbo with 85K miles on it (about 50K miles were ECU tuned) I suddenly had a new problem with the MINI. It was dumping boost with the aftermarket tune files. I don't believe that it's a tune related issue but probably has to do with all of the modifications to the MINI. My tune files are set to stay below the overboost trip points that would cause the ECU to dump all boost. I also think that my turbo was already not right when my MINI was first tuned.


After analyzing a ton of data from the Android Torque APP (sorry, iPhone people, you don't have this APP) it looks like the MINI is not overboosting but the boost is simply spiking. This boost spike is all the ECU needs to see to dump boost down to about 7-8 PSIg. Maybe having a much better flowing intake and a high flow exhaust system is simply allowing the turbo to spool up more quickly which is inducing the spike.

I Installed a boost control valve on my MINI ten days ago and there have been no boost dumps since installing the boost control valve. What I do experience now is full boost (20 PSIg) until I lift the throttle.


The boost control valve is a simple ball check valve with a spring to keep tension on the ball. You set the relief point manually for the boost control valve. It comes with two springs; you'll need to use the high pressure spring.


When boost spikes or the MINI overboosts the spring compresses and the excess pressure is routed to the turbo's internal wastegate. This action allows the wastegate to slightly open and divert some of the exhaust gas away from the exhaust turbine side of the turbo. When the boost spike or overboost condition is gone the boost control valve closes, which closes the wastegate, and your still in full boost. Boost spikes are very bad for both your engine and the turbo so installing the boost control valve is a win-win situation for your MINI.

Installation is straight forward and fairly simple. If you've installed a boost tap port you can tap off right there for your boost feed to the boost control valve.

Since I'm using the Android Torque APP I've removed my boost port tap so I simply tapped into the noise maker plug on the turbo cold side piping by drilling and tapping the plug to install a 1/8" NPT nipple. If you haven't removed your noise maker, you should. Here are a few pictures:





For tapping into the line which connects to the turbo's internal wastegate see below diagram:




Where you place your boost control valve is simpley a matter of choice. I used about 5 feet of 3/16" fuel line and a "T" connector to connect everything into the system.

The screen capture below is from the Android Torque App which shows 20.5 PSIg of boost. Solid boost with no boost dumps.

 

Hi, I´ve just finished a bigger turbo proyect on a THP engine like Mini (Peugeot 207) And I´m having the same problem, boost peaks, Pictures are missing in your post so I really don´t anderstand what you did.
Could you expain me with little more detail?

Thanks..

 

Sorry, now I see the pictures...but, what I don´t understand is that this turbo works with vacuum, not pressure. Does the MBC still works???

 

That screen capture from the Torque App was taken while decelerating. The display is showing that peak boost recorded was 20.5 PSIg. The MBC is still working GREAT!!!

 

SO, as far as I understand, you installed de MBC between the wastgate vacumm port and the N75?? again, I´m pretty sure that our waste gate works with vacuum, not pressure, that's why I don't understand how it works, but if it works, it works...

 

Im having the same problem. My turbo overboost and i get no power. Sometimes I even get the "half power engine light" in the tach. Has that happened to anyone? Does anybody know the cause of it?

 

I actually installed it between the intake piping , before the throttle body and the waste gate. It's running in parrallel with the electronic boost control system. By clipping the boost spike before the ECU can react, you stay in full boost.

 

Ok ! I will try it tomorrow...! Thanks

 

Can't seem to find the link to purchase the valve. Can you repost please?

 

This may help explain whats going on...


MBCs are simple devices, spring and ball bearing that you put compressive tension on, which relates to a pressure. Feel free to search around for a DIY on how to build one or search for MBC to buy one. Doesn't have to be a specific one.

 

I was told that a MBC doesn't work on THP engines because wastgate actuator is backwards, it uses vacuum instead of pressure, so, there is nothing to boost at the wastgate... is that right?

 

Sorry for the late answer on this. Yes, the R56 waste gate works off vacuum. Vacuum holds the waste gate closed. As soon has the MBC valve releases pressure into the vacuum line the waste gate cracks open.
The MBC is installed between the pressure control valve the waste gate. The N75 (BOV) is not effected or in this loop.

It's simple and it works.

 

Are you referencing the N75 valve as the pressure convertor [EPPC] (11657595373) or the BOV (11657593273)?

If your referring to the pressure convertor [EPPC] (11657595373) your above drawing is incorrect because the EPPC connects to the vacuum reservoir and the waste gate. There is no connection to ambient pressure.

My MBC valve set up is connected directly to the intake piping for boost pressure. The pressure from the MBC is released the to waste gate vacuum piping.

There is no direct interface with my set up and the BOV (11657593273).

 

Hopefully u are still out there
Do you tap in on the boost side before or after the throttle body.
It appears u have it before the TB. It matters as after will give instant hard vacuum and the before will have pressure. It must be after the throttle body so to tap into the MAP sensor would be good.
Thanks

 

I tapped it before the throttle body because before the throttle body only sees boost, but NEVER vacuum. The vacuum is created after the throttle body closes on the downstream side.

I'm strictly looking to capture any overboost situations. As soon as the throttle body closes any pressure in the intake manifold is immediately drawn into the engine.

 

Is this thread still alive?
Where can one buy this valve?

 

http://www.boostvalve.com/mini-1.6l-turbo-fix.html

 

I'm still running this set up. Currently at 130,000 miles and 220 WHP on the Mustang DYNO at Helix.

 

Thanks. I use to love going to Mystic to see the old sailing ships.
Going to get this setup this week. I'm boosting close to 30 psi with bigger turbo and Manic tune??? I feel this is a great safeguard especially at the track

 

Please tell me you've completely rebuilt that motor? The stock R56 rods are not capable of handling that amount of boost.

 

My manic tune is 23 psi , and that is with a prosport boost gauge, my DC said it was 22.5 .

 

Yeah that's a nice safe boost level. My Manic 3+ is a little hairy.
Supposed to boost to 25 but the E45R just blasts it so fast.
This is why the manual boost control
I was also thinking that tapping into the manifold will allow vacuum to assist is closing the wastegate for quicker response. I can try both pre and post throttle body as I have provisions already in place.
I went with this unit as it has a light weight ceramic ball
BTW I was a automotive machinist for years so a small explosion is fine especially since I have a warranty on motor and trans. Came with the car. Please do not chime in about coverage, voiding warranty or bla bla bla.
I've run auto repair shops for decades now. I want a new motor anyway (factory JCW), pull the head, port,add cams and away we go. Tigger and SPrint went crazy but not needed really.
I've never heard or seen rod failure. I feel all these "piston" failures are caused by detonation. The sintered rods & pistons are plenty strong enough. All the failures are caused by something else like carbon on valve leading to poor atomization = detonation, HPFP not providing the crazy pressure of 1200psi, oil in intake, bad gas, high intake temps, hot plugs, exhaust back pressure and heat build up: especially by the crazy 220f coolant temps (175 is more like it).....all these cause detonation and then a burnt piston/cylinder wall. This also is harsh on the rods which can cause them to break. I would like to know if someone has had a rod break and where. The shocks waves travel right down the rod blasting big and small end bearings and perhaps the "pringle chip" rods will snap but actually they are pretty strong.
I've been hammering my JCW for 20k miles starting 80k miles and nary a problem....yet!!