Aftermarket FPR vs Dual OEM
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Aftermarket FPR vs Dual OEM
I was thinking that since a single OEM FPR can bypass a little less fuel than a walbro 255hp pump can toss at them at idle - what about two OEM FPR's? Watching this forum for a while has left me with one bit of knowledge - aftermarket FPR's can be hit or miss. Some people swear by them, others have had them fail horribly, with them = all brands. But usually OEM FPR's work like any other OEM Honda part...
People are using twin pumps now, and most aftermarket fuel rails (and some d-series rails) can be drilled to accept 2 OEM FPR's. Given that a FPR is just a diaphragm that opens/closes to hit a target pressure for the fuel it bypasses, the OEM units in tandem with larger pumps would just be closed halfway more than a single at any point.
The only downside I can really see is not being adjustable. But in most cases, a 1:1 rising rate works fine, and ~43psi base fuel pressure is ideal for most injectors. Most people that max out a 255HP pump will usually have the cash to buy a very high end FPR anyways.
What's your opinion?
People are using twin pumps now, and most aftermarket fuel rails (and some d-series rails) can be drilled to accept 2 OEM FPR's. Given that a FPR is just a diaphragm that opens/closes to hit a target pressure for the fuel it bypasses, the OEM units in tandem with larger pumps would just be closed halfway more than a single at any point.
The only downside I can really see is not being adjustable. But in most cases, a 1:1 rising rate works fine, and ~43psi base fuel pressure is ideal for most injectors. Most people that max out a 255HP pump will usually have the cash to buy a very high end FPR anyways.
What's your opinion?
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Re: Aftermarket FPR vs Dual OEM (HiProfile)
Intresting.Why don't you just try it? I am willing to bet you probably have most of the parts needed lying around or could easily get.
Whats the max fuel pressure of the oem regulator anyways? more then 65-70 psi?
Whats the max fuel pressure of the oem regulator anyways? more then 65-70 psi?
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Re: Aftermarket FPR vs Dual OEM (cbustuner)
you would need to run a seprate return line for the second regulator or T them together later in the line where it wouldn't cause any resitance to still cause the pressure to rise.I stll think you would need to run a seprate line for it to be a beneficial mod. You would really have to see to find out what kinda of idle pressure is existant after something like this. In my opinion the amount of work or time for benefit doesn't really outweigh the reliability you might think you will get.
There is a first time for everything so i say go for it and be the ginny pig !
I would try a volume test with a walbro at idle first and then apply vaccum to a regulator off the car and on the car to see how much volume you are dealing with.
This would be a start anyways.
There is a first time for everything so i say go for it and be the ginny pig !
I would try a volume test with a walbro at idle first and then apply vaccum to a regulator off the car and on the car to see how much volume you are dealing with.
This would be a start anyways.
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Re: Aftermarket FPR vs Dual OEM (arc_55)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by arc_55 »</TD></TR><TR><TD CLASS="quote">you would need to run a seprate return line for the second regulator or T them together later in the line where it wouldn't cause any resitance to still cause the pressure to rise.I stll think you would need to run a seprate line for it to be a beneficial mod. </TD></TR></TABLE>
If the original return does not pose a flow restriction with an aftermarket or drilled stock regulator, then it won't with 2 regulators coupled with a Y connection either.
Also, you don't need 2 regulators with a walbro, if you have the right oem regulator. There is a thread somewhere on here where j. davis gets into this. If I remember correctly, the 94+ teg regulator is the one to use.
If the original return does not pose a flow restriction with an aftermarket or drilled stock regulator, then it won't with 2 regulators coupled with a Y connection either.
Also, you don't need 2 regulators with a walbro, if you have the right oem regulator. There is a thread somewhere on here where j. davis gets into this. If I remember correctly, the 94+ teg regulator is the one to use.
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Re: Aftermarket FPR vs Dual OEM (arc_55)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by arc_55 »</TD></TR><TR><TD CLASS="quote">I stll think you would need to run a seprate line for it to be a beneficial mod.</TD></TR></TABLE>
When people run the OEM and a big pump, they get high fuel pressure at idle, and 'fix' it by drilling a hole in the FPR to bypass more. I don't have enough experience with dual pumps to know if the stock return line would be a restriction with 500lph worth of fuel. As I kind of hinted at, most people running enough fuel to overwhelm the factory return line more than likely switched to a large AN feed/return lines anyways. Also, if you overwhelm the return line with 2 OEM's, you'd do the same with a aftermarket FPR.
I know JD mentioned that teg FPR, but IIRC he didn't 100% say which one, and its not easy for most people outside of california (or not at a shop/junkyard) to pull the right FPR out of thin air. But now that's brought up, I could see that being a good use for twin walbros, along with an extra return line if needed. If done right, you still maintain OEM reliability.
When people run the OEM and a big pump, they get high fuel pressure at idle, and 'fix' it by drilling a hole in the FPR to bypass more. I don't have enough experience with dual pumps to know if the stock return line would be a restriction with 500lph worth of fuel. As I kind of hinted at, most people running enough fuel to overwhelm the factory return line more than likely switched to a large AN feed/return lines anyways. Also, if you overwhelm the return line with 2 OEM's, you'd do the same with a aftermarket FPR.
I know JD mentioned that teg FPR, but IIRC he didn't 100% say which one, and its not easy for most people outside of california (or not at a shop/junkyard) to pull the right FPR out of thin air. But now that's brought up, I could see that being a good use for twin walbros, along with an extra return line if needed. If done right, you still maintain OEM reliability.
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I actually thought of using 2 oem regulators too. I actually have a rail that I can do that with, without even modifying it. 1 regulator on the top, 1 on the end. Weird how it will accept that.
But my current plan is to use the previously mentioned oem regulator, and a voltage booster with the walbro, with all stock lines for a 600hp e85 fuel system. Since the booster would only kick up voltage to the pump under boost, (when the injectors would use it), the flow capacity of the return system could remain unchanged. So it would work if the supply is big enough, which I'm betting it is.
I don't really care what people say/think about this idea either, I'm still doing it. I searched about it, came up with jack, except some turbo kits use this idea for american cars in lieu of replacing the pump. As far as I know, no one on h-t uses the msd voltage booster.
But my current plan is to use the previously mentioned oem regulator, and a voltage booster with the walbro, with all stock lines for a 600hp e85 fuel system. Since the booster would only kick up voltage to the pump under boost, (when the injectors would use it), the flow capacity of the return system could remain unchanged. So it would work if the supply is big enough, which I'm betting it is.
I don't really care what people say/think about this idea either, I'm still doing it. I searched about it, came up with jack, except some turbo kits use this idea for american cars in lieu of replacing the pump. As far as I know, no one on h-t uses the msd voltage booster.
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Re: Aftermarket FPR vs Dual OEM (HiProfile)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HiProfile »</TD></TR><TR><TD CLASS="quote">I know JD mentioned that teg FPR, but IIRC he didn't 100% say which one</TD></TR></TABLE>
I posted pictures, you boob. You can visually ID them.
I posted pictures, you boob. You can visually ID them.
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Re: Aftermarket FPR vs Dual OEM (rorik)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rorik »</TD></TR><TR><TD CLASS="quote">the 94+ teg regulator is the one to use.</TD></TR></TABLE>
Look on late 80's early 90's accords... If everyone's local pull n pay is like mine they should out number civics and integras 10 to 1.
Look on late 80's early 90's accords... If everyone's local pull n pay is like mine they should out number civics and integras 10 to 1.
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