Hey guys so I got my 11 MCS tuned over this past week at a local shop. As far as mods, cnt exhaust, DOS intake. Alta IC, alta boost tube, alta bov spring. The car was tuned to 18 psi and first time around gave a limp mode of 5psi. Then it's started building boost up but it's builidng up to 22 psi and then the ecu boost cut jumps in. My tuner thinks its the boost control valve or the recirc valve. I was wondering if this has happened to anyone or if anyone knows why the car would not be regulating boost properly with no CELs... Thanks Jim

 

So after your 18psi tune failed to work properly you changed it 22 psi? Or are you saying the boost creeped up past 18 to 22? I'm a little confused what your main concern is, or if you have multiple.

 

It sounds like it could be an issue with the tune. Who was the tuner.

The recir valve will not cause overboost situation , boost is controlled by the pressure converter which controls the vacuum to the wastegate via a PWM signal sent from the ECU. Typically the pressure converter sticks closed and you get low boost instead of high boost. It is normally closed valve so default operation indicated no boost instead of full boost to save the motor in case failure. If overboost is seen the first line of defense is to reduce wastegate duty cycle and open the wastegate , then activate the recir valve to bleed boost pressure , it will sound like a machine gun going off under the hood if you have open air filter.

 

The latter. It is an 18 psi tune which is creeping up to 22

 

Ecu was bench tuned by speedriven in Chicago. I have a local dealer
However he said that they called in a favor with lohen MINI to help him.

 

Interesting he would call Lohen MINI since they are Manic dealer so they load Manic tunes. Diagnosing a glitch in a tune is never fun. You really need to work closely with who created the tune to find out what was changed etc. I would recommend getting in contact with tuner or at least tune installer and getting help. Being that no one knows your tune except the tuner it is hard to help.

 

I've briefly talked with the installer who believes its a mechanical issue. He is going to contact the tuner and explore that route as well.