Full blown recommended 8 and 6 for feed and return with my recent purchase of there fuel system. My gut was telling me do 10 and 8 But I went 10 and 6. And now that ordered and bought the hose man -6 an really looks small

Power ratio between 5-800hp. With e85 or c85 Under 1000hp

So will -6 be ok? How will I know if it's not enough ? Really don't want to waste 100$ on the hose and fittings I bought

 

-6 AN is comparable to a stock size fuel line.

 

So is that size OK for under 1000hp. Will it do ? What problems will occur if it's not large enough and how will I know

 

Not sure honestly. -6 is only for the return side though correct? If full blown recommended it I would leave it alone.

 

I'm making ~800hp on methanol and a single -6 return couldn't keep up.

A return line is one of those things where going too big isn't going to do anything but going too small will start problems with a/f going down the track.

 

My buddy David of Import Auto Pros made just shy of 1000hp on the fullblown setup with just a -6 feed and return, but this was on C16. I don't know how it'll do with E85 or C85.

 

I've made 700+ on e85, twin 255 pumps, and a -8 feed, -4 return, and had no issues with fuel pressure or return woes.

Honestly, -6 should be more than adequate, but -8 line and fittings is probably only like 100-150$.

 

In what? Veyrons?

The ID of a stock Civic fuel line is ~.180".

The ID of a 6AN hose is ~.340"

A 6 AN hose will flow ~1000 lb/hr before it presents a significant restriction.
If your bypass is less than ~1000 lb/hr at idle, -6 is fine.
If your bypass is more than ~1000 lb/hr at idle, you'll need -8 and a PRV with a bypass orifice larger than .200" to avoid pressure creep.