max fuel pressure w/holley? tried 18 psi, got it to work
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max fuel pressure w/holley? tried 18 psi, got it to work
made some mods and it works w/ 18 psi. but i chickened out and went back to 5-6 psi. Anyone think 18 is safe? anyone go HIGHER? How high?
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tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
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tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
why do they sell pumps over 6 psi?hondo383 wrote:why?
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why do many new cars w/EFI use 40-45 psi?
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tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
Re: max fuel pressure w/holley? tried 18 psi, got it to work
very odd you bring this up, we were just discussing this yesterday for a turbo app....
I was no longer driving the car consciously. I was driving it by a kind of instinct, only I was in a different dimension.
West Siloam Dispensary
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
would be easy to run up to ~14 psi boost w/blow thru if the carb can take 18.F1Fever wrote:very odd you bring this up, we were just discussing this yesterday for a turbo app....
.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
In your carb you are just filling the bowl. If 6 or 7 psi does the job why have the needle and seat work with more pressure then is needed.Matt Gruber wrote:why do they sell pumps over 6 psi?hondo383 wrote:why?
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why do many new cars w/EFI use 40-45 psi?
The EFI is designed for a spray patter and the higher fuel pressure increases flow rating. So use as high as 3.75 - 4 bars.
Stan
Stan Weiss/World Wide Enterprises
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http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
Exactly! THAT is why i went back to my old fuel pump.Stan Weiss wrote:In your carb you are just filling the bowl. If 6 or 7 psi does the job why have the needle and seat work with more pressure then is needed.Matt Gruber wrote:why do they sell pumps over 6 psi?hondo383 wrote:why?
Stan
But, there appears to be guys that might NEED that capacity, like with a blower.
.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
Hulley carbs are designed for 6 psi===what are you trying to prove ??
JOE SHERMAN RACING
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
Joebigjoe1 wrote:Hulley carbs are designed for 6 psi===what are you trying to prove ??
JOE SHERMAN RACING
i bought a carter fuel pump at a swap meet. it was the exact same model i was using for 10 years. it flooded and i thought it must be 1 or 2 psi higher than my old pump. so i fixed the carb so it didn't flood. then i got to thinking, "i better check the psi" so i put my gauge on and it pegs it. so i dug up a higher gauge and it was 18! so i put my 10 yr old pump back on.
So, i posted it here in case it might be an interesting topic for racers. i'm afraid to use it, but, maybe i'll learn something.
Thanks for asking! I enjoy reading your posts! You have an amazing amount of experience!
.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
.
tame a lumpy cam for the street, more street torque! see my article, archived in the waybackmachine.
https://web.archive.org/web/20130707064 ... TGRU/carb/
Great manners equals more fun.
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
people who think more pressure is better are wrong=== I know for a fact that some Prostock racers only run 3,5 to 4.0 pounds on a 1460 horsepower engine= If it seems like more pressure is better , there is something else VERY WRONG
JOE SHERMAN RACING
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
When running as blow thru you need to remember that the fuel inlet pressure may be higher than 4-6psi BUT this pressure will be relative to the boost pressure that is inside the fuel bowl. IE- if you run 10psi boost in blow thru form then to maintain a relative fuel pressure of say 6psi you need 16psi in the fuel line. In this instance the needle and seat only sees this ar 6psi ( the difference between bowl pressure(from boost) and fuel inlet pressure.)
As Joe says, too much pressure is not so good with a carb. The more pressure thru the needle and seat, the more fuel foaming/airation will occur which is BAD for maintaining an accurate feel curve. If you cant get enough fuel flow in there with 5psi in the line, then you need to rework the fuel system to flow more fuel at 5psi.
As Joe says, too much pressure is not so good with a carb. The more pressure thru the needle and seat, the more fuel foaming/airation will occur which is BAD for maintaining an accurate feel curve. If you cant get enough fuel flow in there with 5psi in the line, then you need to rework the fuel system to flow more fuel at 5psi.
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
More PSI means easier to leak fuel Only "benefit" I can think of, lol.
Re: max fuel pressure w/holley? tried 18 psi, got it to work
The self regulated Carters are total junk, I have seen a dozen in the last year that did not work as advertised,. pressures from 2 psi to 16 psi, and never consistant. Now I use the non regulated Carters with seperate regulator.Matt Gruber wrote:Joebigjoe1 wrote:Hulley carbs are designed for 6 psi===what are you trying to prove ??
JOE SHERMAN RACING
i bought a carter fuel pump at a swap meet. it was the exact same model i was using for 10 years. it flooded and i thought it must be 1 or 2 psi higher than my old pump. so i fixed the carb so it didn't flood. then i got to thinking, "i better check the psi" so i put my gauge on and it pegs it. so i dug up a higher gauge and it was 18! so i put my 10 yr old pump back on.
So, i posted it here in case it might be an interesting topic for racers. i'm afraid to use it, but, maybe i'll learn something.
Thanks for asking! I enjoy reading your posts! You have an amazing amount of experience!
Rick
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
R.Olds wrote:The self regulated Carters are total junk, I have seen a dozen in the last year that did not work as advertised,. pressures from 2 psi to 16 psi, and never consistant. Now I use the non regulated Carters with seperate regulator.Matt Gruber wrote:Joebigjoe1 wrote:Hulley carbs are designed for 6 psi===what are you trying to prove ??
JOE SHERMAN RACING
i bought a carter fuel pump at a swap meet. it was the exact same model i was using for 10 years. it flooded and i thought it must be 1 or 2 psi higher than my old pump. so i fixed the carb so it didn't flood. then i got to thinking, "i better check the psi" so i put my gauge on and it pegs it. so i dug up a higher gauge and it was 18! so i put my 10 yr old pump back on.
So, i posted it here in case it might be an interesting topic for racers. i'm afraid to use it, but, maybe i'll learn something.
Thanks for asking! I enjoy reading your posts! You have an amazing amount of experience!
Rick
I've a carter mechanical hi volume pump(CRT-M6624) in my SBC and it varies the pressure all the way from 4 to 16 psi ...
With the engine hot the pressure is aways low...I thought that it had a vapor lock problem or something...
Now this tread help me put the guilt on my pump!
'71 Z28 street strip car
Pump gas All motor SBC 427
3308 lbs-29x10.5 Hoosiers
NEW BEST ET
1.38 60' / 4.05 330' / 6.32@111.25mph
https://www.youtube.com/watch?v=99p13UK ... ture=share
Pump gas All motor SBC 427
3308 lbs-29x10.5 Hoosiers
NEW BEST ET
1.38 60' / 4.05 330' / 6.32@111.25mph
https://www.youtube.com/watch?v=99p13UK ... ture=share
- Stan Weiss
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Re: max fuel pressure w/holley? tried 18 psi, got it to work
Shouldn't this be done with a boost reference regulator and not running the higher pressure all of the time?cjperformance wrote:When running as blow thru you need to remember that the fuel inlet pressure may be higher than 4-6psi BUT this pressure will be relative to the boost pressure that is inside the fuel bowl. IE- if you run 10psi boost in blow thru form then to maintain a relative fuel pressure of say 6psi you need 16psi in the fuel line. In this instance the needle and seat only sees this ar 6psi ( the difference between bowl pressure(from boost) and fuel inlet pressure.)
As Joe says, too much pressure is not so good with a carb. The more pressure thru the needle and seat, the more fuel foaming/airation will occur which is BAD for maintaining an accurate feel curve. If you cant get enough fuel flow in there with 5psi in the line, then you need to rework the fuel system to flow more fuel at 5psi.
Stan
Stan Weiss/World Wide Enterprises
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV
Offering Performance Software Since 1987
http://www.magneticlynx.com/carfor/carfor.htm
David Vizard & Stan Weiss' IOP / Flow / Induction Optimization Software
http://www.magneticlynx.com/DV