Fuel tank vent??

If you're running a FI engine, is a tank vent needed? Or is a vented gas cap gonna get the job done? I have a vented gas cap but would like to know what is the best route to go.

I've been doing FI conversions for years and the vented cap has always seemed to have been fine. I built a few systems that really moved alot of fuel and those tanks had provisions for vents that I used. I couldn't say wether the vented cap would've been enough on those or not. Sorry, it's late, I hope that helped.

Every bit does help. It would not be a big deal to install one later if the gas cap doesn't work out.