Fuel Delivey Issues

[firebob]

69 Firebird-400cid/800cfm Qjet around 450HP. Running Holley Red thru stock 3/8"OD lines-no return line.

Problem: I recently had it dynoed and it seemed to lean out on the top end. I had changed over to the elect pump a long time ago because it would actually run out of fuel at about the 1000ft mark on the stock mech pump. It hasn't done that since the elect was installed but I do notice that it feels like the acceleration flatens out on the top and I'm thinking it's getting fuel starved. I know the qjet has a small fuel bowl but I'm looking for a way to keep it filled better.



I've heard a few guys say that they have run 500HP through the stock fuel lines so I'm looking at the pump arrangement as the culprit. I don't really want to go in deep on big high priced stuff, just a decent delivery system. I'm wondering if I can run a bigger mech pump, add a return line, leave the elect in place and switch it on when I need the extra bump.
Can fuel be pulled through a rotor vane design pump like Red?

[Sean Cooke]

What's your fuel pressure set at?

[sam 74]

Double post

[sam 74]

Holley red should be 7 psi at most and likely dropping to 5 or less at WOT. I'd try a different pump, like a Holley blue or black that way you can regulate the PSI to what the engine wants at WOT. The line size should be ok with you power level, but it can't hurt to go bigger if it's in the budget, also run a return line as it will help the pump live longer.