Fuel Pressure Regulators question
#1
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SideWayZ The Only Way
iTrader: (11)
Joined: Jun 2005
Posts: 4,870
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From: Davie, Florida
Fuel Pressure Regulators question
just curious for people who have had them in, and for how long.. i bought an aeromotive one, i called pettit today because i will be getting the cool charge 3 and 1300s put in but once i told him about it the FPR, he says that the stock one is perfectly fine and the aftermarket ones tent to either leak or fail in about a year or so... just wondering what you guys think and how long you have had it in with no problems.
should i ask him to install it anyways since i already have it?
should i ask him to install it anyways since i already have it?
#5
they won't brake within a year obvioulsy but they do tend to be more leaky than the stock one, keeping the pressure for a shorter time inside the fuel rail when the car is shut off.
The stock would do perfect in your case, reason people change the fpr is because they have aftermarket fuel rail, on which the stock fpr cannot be installed. With your 1300cc, you have a stock fuel rail so stock fpr will work.
I would install a new one though as 15+years of hard heat tend to be hard on the rubber inside of it. Installing an aftermarket one will need some machining of the fuel rail, find fuel hoses and fittings, a place to install it, etc. it is a bigger job than just swapping a part.
just save the money on the installation and buy a new OEM one along with a new pulsation damper if that was not done yet. And sell the aftermarket afterwards.
The stock would do perfect in your case, reason people change the fpr is because they have aftermarket fuel rail, on which the stock fpr cannot be installed. With your 1300cc, you have a stock fuel rail so stock fpr will work.
I would install a new one though as 15+years of hard heat tend to be hard on the rubber inside of it. Installing an aftermarket one will need some machining of the fuel rail, find fuel hoses and fittings, a place to install it, etc. it is a bigger job than just swapping a part.
just save the money on the installation and buy a new OEM one along with a new pulsation damper if that was not done yet. And sell the aftermarket afterwards.
#7
So to my understanding with my setup 850 prim and 1200 sec injectors, I should be able to use my stock fpr and not any problems with my fuel system...no matter what power i'm pushing out?
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#10
you would need at least two fuel pumps on the same line to achieve that though.
#11
gone in circles. Now building fuel delivery system with Canton 1 micron filter, Marren Pulsation Damper , SX Regulator, Goodridge 910 super flex kevlar/teflon hoses, reverse flow through moded stock rails. Already using rewired Cosmo pump and installing RC moded OEM injectors now 650/1220.
#12
Just did a fuel system flow calculation of velocity changes as fuel goes from in line to fuel rail to interconnect hose to 2nd fuel rail to regulator. Mazda was not dumb in selecting flow direction Primary before secondary and rail ID's of 11 and 13 mm. As way Mazda set it up velocity in primary and secondary rails is within 4% of each other, whereas reserve flow has a 172% difference.
OEM setup ,in relative velocity units:
Inlet hose before damper 7.5
Primary Rail 1.58
Hose 5.1
Secondary Rail 1.52
Return hose after FPR 1.50
Reverse flow:
Inlet hose 7.5
Secondary Rail 2.21 (40% increase = pressure drop due to losses) ((would need to bore to 14 mm to get vel down to 1.5) not enough material)
Hose 18.0 (350% increase = Big pressure drop due to losses)
Primary Rail 0.81 (47% flow drop .. good but big imbalance between P/S injectors)
Return hose after FPR 1.50
Conclusion best balance is in OEM direction; this works because primary to secondary ID's decrease but so does flow due to primary bleed off. with 650/1220 injector ratio imbalance goes from 3.8% to 5.5% in other direction. To bring back to balance I need to bore primary rail out to 13.5mm (17/32 drill bit). Bringing final up'd capacity flow velocities to 1.57 in primary (down from 1.68) and 1.54 in secondary. Interconnect hose is at 5.21 up from 5.14, not much change however I am making an -6 connect using Goodrige 710 lines w/ 7 mm bore bring velocity down to 3.8 from stock 5.14
OEM setup ,in relative velocity units:
Inlet hose before damper 7.5
Primary Rail 1.58
Hose 5.1
Secondary Rail 1.52
Return hose after FPR 1.50
Reverse flow:
Inlet hose 7.5
Secondary Rail 2.21 (40% increase = pressure drop due to losses) ((would need to bore to 14 mm to get vel down to 1.5) not enough material)
Hose 18.0 (350% increase = Big pressure drop due to losses)
Primary Rail 0.81 (47% flow drop .. good but big imbalance between P/S injectors)
Return hose after FPR 1.50
Conclusion best balance is in OEM direction; this works because primary to secondary ID's decrease but so does flow due to primary bleed off. with 650/1220 injector ratio imbalance goes from 3.8% to 5.5% in other direction. To bring back to balance I need to bore primary rail out to 13.5mm (17/32 drill bit). Bringing final up'd capacity flow velocities to 1.57 in primary (down from 1.68) and 1.54 in secondary. Interconnect hose is at 5.21 up from 5.14, not much change however I am making an -6 connect using Goodrige 710 lines w/ 7 mm bore bring velocity down to 3.8 from stock 5.14
#13
i have the aeromotive one that comes in the rx7store ultimate fuel system and have had it for 4 years its all hooked up with -6 an fittings and stainless steel braided lines the only thing that leaked was a fuel injector o-ring cause it got pinched when i pushed it in the rail. that fuel pressure regulator is known for not causing leaks because it has a built in fuel pulse damper which is what leaks and causes all the fires in our cars in the first place. and running a stock fpr without the fpd is known to cause injector leaks.
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