2004 E55 looses boost around 5500 RPM
Hey guys, i recently did the 82mm TB upgrade along with 550 injectors. The car already has a 77mm fixed pulley upgraded intercooler pump, split cooling, 3" intake and a tune.
After completing the TB and injectors upgrade the car would loose power when full throttle at about 5500 rpms. i just can't figure it out. it seems like the bypass valve is opening up but I'm not sure why that would be.
Anyone have a similar problem?
I have since done long tube headers, X pipe and cat delete, no change to the above issue.
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