I currently have some questions about the injector choice.

Now I have a slightly ported 13B-REW engine with FC's 8.5cr rotors, I'm planning to make about 420hp on hub dyno. And my current injectors are classic Denso 4*850cc set. But some friends said 850cc will doing too big duty cycles at 400+whp.

I knew the hp numbers are depends on different dynos so let's just say about 420. And I also knew that over killed injectors have more advantages than problems.

But the thing is I probably gonna stay at this setting for some time, and if I'll do more power at next build I'll change injectors anyway.

Do I have to change them now or they will be fine at about 420whp?

 

Search around on google/forum search tool, I usually search "rx7 400hp fuel system" and get quite a few good threads.

Although 4000-4300cc worth of total injector usually seems what most people do to get 400ish... with a better pump ie supra tt, Atm your about 600cc short at 3,400cc's with 4x850's
You might get to 360-380ish before running out of injector. Boosting is definitely the way your going to get there too.

Here's the first one that pops up.
https://www.rx7club.com/new-member-r...-400hp-873880/