fuel pressure question
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From: Va Beach, VA, USA
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Re: fuel pressure question (mythias)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mythias »</TD></TR><TR><TD CLASS="quote">With higher pressure more fuel will flow into the motor with the same injector duration. The higher fuel pressure will also cause better atomization of the fuel.</TD></TR></TABLE>
Here are a few appropriate equations :
http://www.rceng.com/technical.htm
Here are a few appropriate equations :
http://www.rceng.com/technical.htm
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From: Somewhere in MD, MD, USA
Re: (Dave_B)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Dave_B »</TD></TR><TR><TD CLASS="quote">Good to know I was wondering the same thing. I thought you had to get higher flowing injectors for more fuel. Do you happen to know the max or there abouts of the stock injectors?</TD></TR></TABLE>
Don't know the max of stock, but you don't always need bigger injectors to get more fuel into the engine. Sometimes bigger injectors don't run at 100 duty or even close and it can be a waste of money replacing stock, as well as need tuning on a (I believe) wide band to find out what duty your injectors are operating at.
Don't know the max of stock, but you don't always need bigger injectors to get more fuel into the engine. Sometimes bigger injectors don't run at 100 duty or even close and it can be a waste of money replacing stock, as well as need tuning on a (I believe) wide band to find out what duty your injectors are operating at.
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Re: (totsie7944)
My friend had a turbo b16 running off of stock 240cc injectors and an inline fuel pump. It had a 12:1 vortch fmu. The injectors never went out and the motor didn't run lean at all. I never really understood how that worked but it did. My Type R had RC 310's maxed out on stock cams with CTR pistons and stock fuel pump. 
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From: Cuba
Re: (totsie7944)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by totsie7944 »</TD></TR><TR><TD CLASS="quote"> Sometimes bigger injectors don't run at 100 duty or even close and it can be a waste of money replacing stock, as well as need tuning on a (I believe) wide band to find out what duty your injectors are operating at. </TD></TR></TABLE>
With the OEM injectors, you can raise the fuel pressure to allow for a bit more fuel as needed. But you do not want the OEM injectors to be at 100% duty cycle with high fuel pressure. If you have to raise your fuel pressure above 73psi on the OEM injectors at 100% duty cycle, then you need aftermarket. It's just too much stress on the injectors.
Having aftermarket injectors that only run at 40-50% duty cycle is not a waste. You are not stressing the injectors, or your fuel pump. It also allows room for additional fuel needs if you modify your setup.
If you have an OEM ECU and injectors, you can raise your fuel pressure to compensate for mild additional fuel needs. Keep in mind that it is not a 1:1 ratio. Twice the pressure does not mean twice the fuel.
If your fuel needs are more than mildly above stock, then just go with larger injectors and a tunable engine managment system.
With the OEM injectors, you can raise the fuel pressure to allow for a bit more fuel as needed. But you do not want the OEM injectors to be at 100% duty cycle with high fuel pressure. If you have to raise your fuel pressure above 73psi on the OEM injectors at 100% duty cycle, then you need aftermarket. It's just too much stress on the injectors.
Having aftermarket injectors that only run at 40-50% duty cycle is not a waste. You are not stressing the injectors, or your fuel pump. It also allows room for additional fuel needs if you modify your setup.
If you have an OEM ECU and injectors, you can raise your fuel pressure to compensate for mild additional fuel needs. Keep in mind that it is not a 1:1 ratio. Twice the pressure does not mean twice the fuel.
If your fuel needs are more than mildly above stock, then just go with larger injectors and a tunable engine managment system.
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From: NYOB, where is mah gun, USA
Re: (mythias)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mythias »</TD></TR><TR><TD CLASS="quote">Having aftermarket injectors that only run at 40-50% duty cycle is not a waste. You are not stressing the injectors, or your fuel pump. It also allows room for additional fuel needs if you modify your setup.</TD></TR></TABLE>
thats the same thing i was thinking
thats the same thing i was thinking
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Re: (totsie7944)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by totsie7944 »</TD></TR><TR><TD CLASS="quote">
Don't know the max of stock, but you don't always need bigger injectors to get more fuel into the engine. Sometimes bigger injectors don't run at 100 duty or even close and it can be a waste of money replacing stock, as well as need tuning on a (I believe) wide band to find out what duty your injectors are operating at.
</TD></TR></TABLE>
i guess it would depend on type of injectors, and stock setup can be at 100% rate, but from what i know you don't want to go over 80%, for example rc injectors..
thats what make fmu so dangerous, it overloads stock injectors
Don't know the max of stock, but you don't always need bigger injectors to get more fuel into the engine. Sometimes bigger injectors don't run at 100 duty or even close and it can be a waste of money replacing stock, as well as need tuning on a (I believe) wide band to find out what duty your injectors are operating at.
</TD></TR></TABLE>
i guess it would depend on type of injectors, and stock setup can be at 100% rate, but from what i know you don't want to go over 80%, for example rc injectors..
thats what make fmu so dangerous, it overloads stock injectors
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Re: (mythias)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by mythias »</TD></TR><TR><TD CLASS="quote">With the OEM injectors, you can raise the fuel pressure to allow for a bit more fuel as needed. But you do not want the OEM injectors to be at 100% duty cycle with high fuel pressure. If you have to raise your fuel pressure above 73psi on the OEM injectors at 100% duty cycle, then you need aftermarket. It's just too much stress on the injectors.
Having aftermarket injectors that only run at 40-50% duty cycle is not a waste. You are not stressing the injectors, or your fuel pump. It also allows room for additional fuel needs if you modify your setup.
If you have an OEM ECU and injectors, you can raise your fuel pressure to compensate for mild additional fuel needs. Keep in mind that it is not a 1:1 ratio. Twice the pressure does not mean twice the fuel.
If your fuel needs are more than mildly above stock, then just go with larger injectors and a tunable engine managment system.</TD></TR></TABLE>
i could be wrong but isnt optimal fuel atomization at 55psi on the b18c5 or other b series motors as well?
Having aftermarket injectors that only run at 40-50% duty cycle is not a waste. You are not stressing the injectors, or your fuel pump. It also allows room for additional fuel needs if you modify your setup.
If you have an OEM ECU and injectors, you can raise your fuel pressure to compensate for mild additional fuel needs. Keep in mind that it is not a 1:1 ratio. Twice the pressure does not mean twice the fuel.
If your fuel needs are more than mildly above stock, then just go with larger injectors and a tunable engine managment system.</TD></TR></TABLE>
i could be wrong but isnt optimal fuel atomization at 55psi on the b18c5 or other b series motors as well?
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From: Somewhere in MD, MD, USA
Re: (mythias)
Brad great information. Based upon this it looks like I may have to look into bigger injectors then if I want to get my extra modifications.
I am going to be getting the Toda C's as well because I don't think I will make the power I should with the SMSP header and the spec B's I have now. Also, I am wondering if my Rc 310's will be large enough for the additional modifications....
I am going to be getting the Toda C's as well because I don't think I will make the power I should with the SMSP header and the spec B's I have now. Also, I am wondering if my Rc 310's will be large enough for the additional modifications....
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Re: (totsie7944)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by totsie7944 »</TD></TR><TR><TD CLASS="quote">Brad great information. Based upon this it looks like I may have to look into bigger injectors then if I want to get my extra modifications.
I am going to be getting the Toda C's as well because I don't think I will make the power I should with the SMSP header and the spec B's I have now. Also, I am wondering if my Rc 310's will be large enough for the additional modifications....</TD></TR></TABLE>
As I said a few posts up....I had RC 310's running almost full duty cycle on stock cams and CTR pistons. I would go with some thing bigger than 310's with C's.
I am going to be getting the Toda C's as well because I don't think I will make the power I should with the SMSP header and the spec B's I have now. Also, I am wondering if my Rc 310's will be large enough for the additional modifications....</TD></TR></TABLE>
As I said a few posts up....I had RC 310's running almost full duty cycle on stock cams and CTR pistons. I would go with some thing bigger than 310's with C's.
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Re: (Rdriver)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rdriver »</TD></TR><TR><TD CLASS="quote">
As I said a few posts up....I had RC 310's running almost full duty cycle on stock cams and CTR pistons. I would go with some thing bigger than 310's with C's.</TD></TR></TABLE>
You could have upgraded the fuel pump instead.
As I said a few posts up....I had RC 310's running almost full duty cycle on stock cams and CTR pistons. I would go with some thing bigger than 310's with C's.</TD></TR></TABLE>
You could have upgraded the fuel pump instead.
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Re: (El Pollo Diablo)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by El Pollo Diablo »</TD></TR><TR><TD CLASS="quote">You could have upgraded the fuel pump instead.</TD></TR></TABLE>
DOH! I forget to mention about upgrading the fuel pump. The RC 310's would have been sufficient with a 255lph fuel pump.
DOH! I forget to mention about upgrading the fuel pump. The RC 310's would have been sufficient with a 255lph fuel pump.
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