Well my fully built ZC is in the home stretch and i'm focusing on my fuel management recently. I originally was thinking 550's would be suffient to feed my engine, just like some opinions or some mathmatical way of of figuring the correct flow rate. My setup will be a t3/t4 boosting between 15-20 psi, i may also go up to 25 psi tops. I'll be running either Hondata or Zdyne and a walbro high flow fuel pump. I believe that's all you'll need to know to make an informed opinion. If you need any more info plz post it. Any info will be greatly appreciated. Thanks

 

Do a search, there is A TON of info if you do the search right. I just looked for the same topic the other day.

If you plan on going all the way up to 25psi...you'll have to go bigger than the 550cc's..

 

I have maxed out 450cc's at 286WHP , I would say 550cc's would be about done at 330WHP.
That should give you an idea.