1NZFE Safe REV limit

[Parmas]

Originally Posted by cali yaris

The point remains the same. It's wherever the car stops making power. I can't imagine a build on the 1NZ that would require 8k or 9k rpms, so the question doesn't hold much relevance for me.

besides camshafts, you better have springs and some other head work done to access higher rpms safely.

Could you share your opinion what do you mean by better springs? or else what springs do you recommend