Hello,

I recently bought an '03 R53 and I was told when I bought it that it had a lack of boost. I believed this to be the SC, but I opened the SC up and it is perfectly fine. I have now installed a 17% reduction pulley, DDMWorks intake, one step colder spark plugs, and have replaced the valve cover gasket. I also checked the crank pulley (harmonic balancer), as I read that it can cause a lack of boost, but it was fine.

The car is now put back together and running, and has a nice whine going from the DDM intake, but I have no reference to tell whether it is as powerful as it should be as I have never driven an R53 before this. I have also driven it with the BPV tied shut and not tied shut, but I wasn't sure whether I could tell a difference.

This has left me in a position where I do not know whether the car really was running with a lack of boost, as I was told, or if it still is now. So I simply need to know how I can read the boost pressure and what I should look for to tell whether the car is in good running order or not.

 

Get a mechanical boost-vacuum gauge, and plumb it into the intake manifold. That will tell you immediately if there is a boost or vacuum problem.

 

Yeps, you can also check with an OBD dongle and something like the Torque app. I use both and both sources will give back the same values. My 06 JCW with 11% pulley builds a solid 0.9 BAR boost.