[Vovo850R]

Hi! I read what you write and recommend cat so then I will use a catalyst. Maybe I should go up a notch in turbo to a TD04-20T? What do you think? When will a 20 T with billet compressor wheel start to do boost? 2500 RPM?
Thanks for all the help so far.

[Marlboroman]

Already with a 19T with #7 rear housing you will have considerable issues with backpressure. An even bigger compressor will not be beneficial without another turbinewheel. And even then i might not be the best solution. A K24 might be another option if you want more power.