Hello,

Recently I have been having an issue with the boost pressure in my R56 Mini cooper S. I have installed several modifications including an alta 3" exhaust, 100cell catted downpipe, larger intercooler, air intake, JCW turbo, Alta boost tubes, and an alta recirculation valve. I am using the Cobb Accessport for tuning.

The problem that I have is as follows:

Stock tune - no problems with boost. Turbo makes 16psi on average
Stage 1 tune - no problems with boost. Turbo makes 20psi on average
Stage 2/3 tune - turbo builds boost very quickly to 22psi then cuts boost pressure down to 0-5psi in second to sixth gears.

The ECU is not spitting out any error codes for me to work off of.

Our thinking is that the wastegate is not releasing pressure fast enough to keep up with the ECU's 22psi limit and then subsequently dumping the pressure all at once.

The thing is that I do believe the wastegate is working properly, it just can't compensate for the quicker buildup of pressure.

Has anyone had this issue before? Any idea how to fix it?

Thank you in advance for your help!

 

Ditch the Access Port and Contact Board Member Mario Kart. With all your mods, you need to get a real tune. I had an access port on my old 2010 and had nothing but issues.

Mario Kart's customer service is the best in the game. Trust me send your ECU to Mario. Easy to remove. Took 5 minutes, and had it back the next day. Smiles for miles.

 

Hi Everyone, new here i have the same issue on my r56 Cooper S 2011.
Similar tune... Did you find solution to solve this overboost ?

Thanks guys