Need help on rattling noise

Hi all,

I was wondering if you guys can give some advice and help on my problem.

I have a r34 skyline gtt ( rb25det) and have recently installed the apexi AVCR boost controller. Have set it to 1 bar boost on the dyno with rate of 72%.

In addition the other modifications to the car are the apexi ITC as well as the apexi AFC. I have also got a HKS SQV blow off valve. My rear exhast has also been modified to a straight pipe and the catalytic converter removed.

My problem is that after the recent installment of the AVCR, there is a rattling noise once the turbo spools to 0.2-0.3 bars. Apart from the noise the car is running perfectly well.

Any ideas on the cause of it and am I doing any thing detrimental to the car turbo?

Also any ideas on what turbo I can upgrade to? (I'm not looking for much, just being able to sustain the 1 bar boost comfortably with no modifications to the engine itself.)

Thanks