Reply With QuoteI dont see a problem with it, But my cousins boat has a pretty hot motor, 585+ horse's on it, and he is keep it around 7. I guess it would come down to you dont want to give it more that it can use to keep 100% efficently
Hey guys, i have a 130gph holley marine mechanical fuel pump that feeds through a barry grant fuel pressure regulator that splits dual fuel lines into a holley 850dp. the pump has 8an to the regulator and 6an from the regulator to the carb. the fuel pressure gauge. the fuel pressure with this setup was 6 1/2lb at idle and 5lb or less at full throttle with the regulator set wide open. i removed this set up and went from the pump to the carb with the same size lines. now the pressure is 7 1/2lb at idle and 8lb on the throttle.
My queastion is will i be ok with this pressure. i run a engine cover and dont want any suprises.I am sure not impressed with the $100.00 barry grant regulator.
I dont see a problem with it, But my cousins boat has a pretty hot motor, 585+ horse's on it, and he is keep it around 7. I guess it would come down to you dont want to give it more that it can use to keep 100% efficently
I've always heard the the Holley needle/seat assembly is good to 8 psi. I'm running mine there and haven't had any issues. Holley 130 gal per hr mechanical (9 psi max I think) on a tunnelram with dual 660 mechanicals (crappy Holley regulator which is pretty much adjusted all the way out anyway). -8AN to regulator and -6AN to the carbs.
I Heard Barry Grant Carbs. Could Hold 9 Psi.i Run 8 To My 1150s.#8 An To #6 An Hard Lines On Each Carb.
Here is how I have learned it
The regulator is usually needed to keep the pressure down at idle with a HV/HP pump. A lot of times with out it at idle or part throttle you will run to rich, pushing fuel past the valve or seat. People try to jet it down or pull fuel to keep from fouling plugs an running like crap. However a lot of the time once this is done as soon as you go into WOT the adjustment is way off at that point. (mostly to lean)
In the end the carb and the AFR are all out of whack. Some carbs cam take 10-12 psi at idle with out a problem. The regulator aids you in increasing the volume of fuel at Wide Open Throttle (WOT) and keeping your pressure in line at cruise and idle.
On my BBC I have 1/2" line a 255lph pump and my regulator is set at 9 psi it stays there 99% of the time. Unless your a FI application the high pressure is usually not needed (above 7-10 psi) It is all about keeping the volume up. If you have a good regulator and pump your pressure will only drop .5 - 2psi going from cruise to WOT.
anyone disagree?
Buy the way, I have flowed many holly pumps and they usualy fall short of their rated volume and then the PSI drops.
In fact one nitrous application using a holly blue pump the AFR went from 11.9 (slightly rich) to 13.5 (dangerously lean) at 5800K on a 700hp motor and droped it to the 63x range.
Flowing fuel systems is not done enough if you ask me once you go past the 500-600 mark or when a power adder is used.
Thanks guys. I am going to run it. I hope to see a better response without the low fuel pressure with the regulator in line.
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