how much fuel pressure is enough?

[kanedog]

I have a 540 merlin block,14/71 littlefield,1250 dominators(c&j),innercooler,8oo hp(6 lbs boost) on pump and 950(9 lbs boost) on race gas with pulleys switched.
I presently run 6 lbs of fuel pressure and i would like to know what others with a similar setup are running for fuel pressure?

[Craig]

My 509 (878 hp) has a B&M 420 w/2 750 DP Holleys. It holds 6-7 pounds through out the rpm range running a blue or black Holley electric. I am switching over to a BDS return style regulator to try and ease some heat build in the pump motor during excessive idle periods.

[UBFJ #454]

We run between 6.5 & 7.5 max. on our 1150's.
[ September 17, 2003, 06:56 PM: Message edited by: BEAR_454PE ]

[502procharger]

bout a million pounds, yeah bout a million pounds

[spectras only]

Kane, the Mallory 110 electric racepump with built in regulator [ Lordco sells them for around $350] should maintain 7-8 # at wide open :cool: .
[ September 11, 2003, 11:17 AM: Message edited by: spectras only ]

[kanedog]

why wouldnt i want to run 8 or above lbs fuel pressure?Im wondering as some automotive friends are saying i should be at 8 or 9 lbs.Thanks for the advice so far

[Craig]

I think the needle & seat that controls your fuel level is designed for 6-7 pounds. More than that and it will force the fuel past the seat and flood the motor.

[paradigm shift]

If your fuel inlet seats are sized properly 6psi at WOT is more than enough. Craig is correct to much pressure and you will have fuel level control issues from the pressure overriding the float and seat capacity to seal.
I run a 1071 with 2 850's and 5psi at WOT. No problems. I only run 5psi on boost and a little less HP so I don't need quite as much fuel as you. I run a high volume mechanical pump.
Do you think you are running out of fuel now?

[kanedog]

no,not running out of fuel but have had knowledgeable racing/auto guys on board and they squirm at the site of only 6 lbs boost,they think it should be more.i have not been running out of fuel and am happy at 6 but just need some back up from boating buddies.thanks

[F N Fast]

Running 12 to 13 PSI on mine, holds a solid 10 at WOT.
Have dual 1150's on top of an 1471 PSI Blower. Anything less I'd be concerned about sucking the bowls dry.

[TANK]

Should be between 6 and 7#'s.Any more and it could blow the needle off of its seat

[SuperWrench0166]

as long as it hold steady pressure at wide open your fine with 6-7 its more a concern of volume then pressure