For anybody thats wondering about this, I just went against a 335i coupe and we were dead even 0-100.
I talked to the guy afterwards and he had almost full bolt-ons, only missing test pipes (my z is bone stock, touring no sport package). for anybody thats wondering, I know I've looked around for this comparison and only found Z vs 135i. (This was on a closed course, not street racing)
Edit: I timed the 0-60 and it was 5.0 flat. I think this was a fairly good time for my car. didn't get 0-100 though.