How much horsepower will my fuel system support?
10-18-2012, 11:20 AM
#5
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the 255 liter per hour pump along with all the stock fuel feeding components, except for injectors will get you ~500hp.
injectors...37# I'm guessing that are listed directly on Racetronixs website... then they are actually 42.72# injectors at our fuel pressure (58psi, 4 bar).
Another kicker... as you increase boost, you increase the pressure pushing back on the fuel injector, as the fuel injector is in the intake stream path of the said BOOST. So for every 1psi you increase of boost, you can take 1psi worth of capability away, which equates to a square root curve drop off of flow. 58psi NET, 7LBs of boost equated to 51psi injector fuel pressure...equivalent injector rating of 40# injectors.
Hence the reason people run Fuel pressure regulators that are manifold referenced.
Without running the MAP referenced FPR, you will need larger and larger fuel pumps & injectors to keep up versus increasing fuel pressure equivalent to boost pressure.
The best bet with your current setup is to sell those 37# injectors and purchase some 42# injectors so that you are for certain in the operating range of all the components you have. That would allow you to run ~6psi and not have any worry of maxing out your fuel components. If you needed more fuel, Nasty N8 or Lonnies can help you with any of your needs. Also FIC Injectors.
What turbo do you have with that setup? A 67mm? if so, and you run it on a basic bolt on ls1 @7~8lbs you likely will make ~480+ and would likely be getting a high duty cycle on those 37# (42.72#@58) injectors.
should be more than that with those injectors.
10-18-2012, 05:20 PM
#6
the 255 liter per hour pump along with all the stock fuel feeding components, except for injectors will get you ~500hp.
injectors...37# I'm guessing that are listed directly on Racetronixs website... then they are actually 42.72# injectors at our fuel pressure (58psi, 4 bar).
Another kicker... as you increase boost, you increase the pressure pushing back on the fuel injector, as the fuel injector is in the intake stream path of the said BOOST. So for every 1psi you increase of boost, you can take 1psi worth of capability away, which equates to a square root curve drop off of flow. 58psi NET, 7LBs of boost equated to 51psi injector fuel pressure...equivalent injector rating of 40# injectors.
Hence the reason people run Fuel pressure regulators that are manifold referenced.
Without running the MAP referenced FPR, you will need larger and larger fuel pumps & injectors to keep up versus increasing fuel pressure equivalent to boost pressure.
The best bet with your current setup is to sell those 37# injectors and purchase some 42# injectors so that you are for certain in the operating range of all the components you have. That would allow you to run ~6psi and not have any worry of maxing out your fuel components. If you needed more fuel, Nasty N8 or Lonnies can help you with any of your needs. Also FIC Injectors.
What turbo do you have with that setup? A 67mm? if so, and you run it on a basic bolt on ls1 @7~8lbs you likely will make ~480+ and would likely be getting a high duty cycle on those 37# (42.72#@58) injectors.
should be more than that with those injectors.
injectors...37# I'm guessing that are listed directly on Racetronixs website... then they are actually 42.72# injectors at our fuel pressure (58psi, 4 bar).
Another kicker... as you increase boost, you increase the pressure pushing back on the fuel injector, as the fuel injector is in the intake stream path of the said BOOST. So for every 1psi you increase of boost, you can take 1psi worth of capability away, which equates to a square root curve drop off of flow. 58psi NET, 7LBs of boost equated to 51psi injector fuel pressure...equivalent injector rating of 40# injectors.
Hence the reason people run Fuel pressure regulators that are manifold referenced.
Without running the MAP referenced FPR, you will need larger and larger fuel pumps & injectors to keep up versus increasing fuel pressure equivalent to boost pressure.
The best bet with your current setup is to sell those 37# injectors and purchase some 42# injectors so that you are for certain in the operating range of all the components you have. That would allow you to run ~6psi and not have any worry of maxing out your fuel components. If you needed more fuel, Nasty N8 or Lonnies can help you with any of your needs. Also FIC Injectors.
What turbo do you have with that setup? A 67mm? if so, and you run it on a basic bolt on ls1 @7~8lbs you likely will make ~480+ and would likely be getting a high duty cycle on those 37# (42.72#@58) injectors.
should be more than that with those injectors.
10-23-2012, 12:04 AM
#7
the 255 liter per hour pump along with all the stock fuel feeding components, except for injectors will get you ~500hp.
injectors...37# I'm guessing that are listed directly on Racetronixs website... then they are actually 42.72# injectors at our fuel pressure (58psi, 4 bar).
Another kicker... as you increase boost, you increase the pressure pushing back on the fuel injector, as the fuel injector is in the intake stream path of the said BOOST. So for every 1psi you increase of boost, you can take 1psi worth of capability away, which equates to a square root curve drop off of flow. 58psi NET, 7LBs of boost equated to 51psi injector fuel pressure...equivalent injector rating of 40# injectors.
Hence the reason people run Fuel pressure regulators that are manifold referenced.
Without running the MAP referenced FPR, you will need larger and larger fuel pumps & injectors to keep up versus increasing fuel pressure equivalent to boost pressure.
The best bet with your current setup is to sell those 37# injectors and purchase some 42# injectors so that you are for certain in the operating range of all the components you have. That would allow you to run ~6psi and not have any worry of maxing out your fuel components. If you needed more fuel, Nasty N8 or Lonnies can help you with any of your needs. Also FIC Injectors.
What turbo do you have with that setup? A 67mm? if so, and you run it on a basic bolt on ls1 @7~8lbs you likely will make ~480+ and would likely be getting a high duty cycle on those 37# (42.72#@58) injectors.
should be more than that with those injectors.
injectors...37# I'm guessing that are listed directly on Racetronixs website... then they are actually 42.72# injectors at our fuel pressure (58psi, 4 bar).
Another kicker... as you increase boost, you increase the pressure pushing back on the fuel injector, as the fuel injector is in the intake stream path of the said BOOST. So for every 1psi you increase of boost, you can take 1psi worth of capability away, which equates to a square root curve drop off of flow. 58psi NET, 7LBs of boost equated to 51psi injector fuel pressure...equivalent injector rating of 40# injectors.
Hence the reason people run Fuel pressure regulators that are manifold referenced.
Without running the MAP referenced FPR, you will need larger and larger fuel pumps & injectors to keep up versus increasing fuel pressure equivalent to boost pressure.
The best bet with your current setup is to sell those 37# injectors and purchase some 42# injectors so that you are for certain in the operating range of all the components you have. That would allow you to run ~6psi and not have any worry of maxing out your fuel components. If you needed more fuel, Nasty N8 or Lonnies can help you with any of your needs. Also FIC Injectors.
What turbo do you have with that setup? A 67mm? if so, and you run it on a basic bolt on ls1 @7~8lbs you likely will make ~480+ and would likely be getting a high duty cycle on those 37# (42.72#@58) injectors.
should be more than that with those injectors.
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10-23-2012, 07:33 PM
#8
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I said all components except those injectors will support those numbers. Another set of ACTUAL 42# injectors would be 48.5# injectors at our fuel pressure. please know the rated fuel psi and application psi.
10-23-2012, 10:31 PM
#9
I understand fuel pressure and when I was talking about the 42's I was also talking about 4bar fuel pressure (which would be assumed for our cars). It doesn't make since to buy something that is only slightly bigger (since you were talking about 48.5's). Just buy some Siemens 60's and be done with it. And since you like application psi, that would be 72.98 lb/hr at 58 psi for a static flow rate. Plenty of injector for when the OP decides to keep growing.
10-25-2012, 07:48 PM
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The first sentence doesn't make sense. You literally quoted the same numbers I did for both the pump and the injectors. I don't understand why your trying to correct me...
I understand fuel pressure and when I was talking about the 42's I was also talking about 4bar fuel pressure (which would be assumed for our cars). It doesn't make since to buy something that is only slightly bigger (since you were talking about 48.5's). Just buy some Siemens 60's and be done with it. And since you like application psi, that would be 72.98 lb/hr at 58 psi for a static flow rate. Plenty of injector for when the OP decides to keep growing.
I understand fuel pressure and when I was talking about the 42's I was also talking about 4bar fuel pressure (which would be assumed for our cars). It doesn't make since to buy something that is only slightly bigger (since you were talking about 48.5's). Just buy some Siemens 60's and be done with it. And since you like application psi, that would be 72.98 lb/hr at 58 psi for a static flow rate. Plenty of injector for when the OP decides to keep growing.
My point about getting the 42s (being 48.5 at our pressure) is that it is just under the flow maximum of the 255 pump, so you know you won't have an issue of losing fuel pressure. I do agree that I would rather have the 60's at that point, but I would also advise upgrading the pump with it. With what he has, he would likely be ok without doing so. do it right, do it once.
What math are you doing to get 60# @ 43.5psi to 72.98 @ 58psi ? I'm not getting the same result with the flow relating to the square root of the pressure difference?
sqrt ( 58psi / 43.5psi) = 1.1547 ; 1.1547 * 60 = 69.3#
http://rceng.com/technical.aspx
10-28-2012, 11:32 PM
#11
I was being lazy and found the info on a site, but I can't find it now. But after doing the math based on the specs here:
http://siemensdeka.com/specsheets/FI114961.jpg
Sqrt(58psi/43.5) = 1.1547 * 61 = 70.4lbs
Pretty close
http://siemensdeka.com/specsheets/FI114961.jpg
Sqrt(58psi/43.5) = 1.1547 * 61 = 70.4lbs
Pretty close
10-30-2012, 02:06 PM
#12
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I was being lazy and found the info on a site, but I can't find it now. But after doing the math based on the specs here:
http://siemensdeka.com/specsheets/FI114961.jpg
Sqrt(58psi/43.5) = 1.1547 * 61 = 70.4lbs
Pretty close
http://siemensdeka.com/specsheets/FI114961.jpg
Sqrt(58psi/43.5) = 1.1547 * 61 = 70.4lbs
Pretty close
Also, with n-heptane versus gasoline:
Injector flow rates are based on testing with n-Heptane test solvent (0.6855 g/ml). U.S. EPA emission test gasoline 40CFR86.113 (0.735g/ml) flows in most common injector designs at about a 3 to 4% higher rate than n-Heptane. A ratio of 1.035:1 can be used when converting the flow specifications above.
