VRP vs Fabtech looped fuel rail - which one?
12-14-2018, 01:25 PM
#2
MBWorld Fanatic!
Wow surprised nobody commented,
I did an experiment a few years ago because the drivers side was always leaner then the passenger side, initially the looped rail evened that out ,but when I kept increasing the boost it went back ,now at high boost levels and a dual feed dual pump set up and even as high as 90 psi WOT it is still leaner on the drivers side ,wierd, I have an SL but that amount of fuel and pressure you would think that wouldn’t happen, did it on pump,race and C85 fuels.can be as high as .7 dif , 11.5 AFR pass side,12.2 AFR drivers side ,yes changed out 02 s and Widebands .Also did it with 550 ,750,1000cc injectors.
I did an experiment a few years ago because the drivers side was always leaner then the passenger side, initially the looped rail evened that out ,but when I kept increasing the boost it went back ,now at high boost levels and a dual feed dual pump set up and even as high as 90 psi WOT it is still leaner on the drivers side ,wierd, I have an SL but that amount of fuel and pressure you would think that wouldn’t happen, did it on pump,race and C85 fuels.can be as high as .7 dif , 11.5 AFR pass side,12.2 AFR drivers side ,yes changed out 02 s and Widebands .Also did it with 550 ,750,1000cc injectors.
Last edited by cnterline; 12-14-2018 at 01:28 PM.
12-14-2018, 02:30 PM
#3
Super Member
Wow surprised nobody commented,
I did an experiment a few years ago because the drivers side was always leaner then the passenger side, initially the looped rail evened that out ,but when I kept increasing the boost it went back ,now at high boost levels and a dual feed dual pump set up and even as high as 90 psi WOT it is still leaner on the drivers side ,wierd, I have an SL but that amount of fuel and pressure you would think that wouldn’t happen, did it on pump,race and C85 fuels.can be as high as .7 dif , 11.5 AFR pass side,12.2 AFR drivers side ,yes changed out 02 s and Widebands .Also did it with 550 ,750,1000cc injectors.
I did an experiment a few years ago because the drivers side was always leaner then the passenger side, initially the looped rail evened that out ,but when I kept increasing the boost it went back ,now at high boost levels and a dual feed dual pump set up and even as high as 90 psi WOT it is still leaner on the drivers side ,wierd, I have an SL but that amount of fuel and pressure you would think that wouldn’t happen, did it on pump,race and C85 fuels.can be as high as .7 dif , 11.5 AFR pass side,12.2 AFR drivers side ,yes changed out 02 s and Widebands .Also did it with 550 ,750,1000cc injectors.
Like the avatar, -Ghost in the Machine. Great album.
12-14-2018, 05:07 PM
#5
MBWorld Fanatic!
12-14-2018, 08:04 PM
#7
MBWorld Fanatic!
I ran dual wide bands and saw the same thing. What I did was run a number 8 steel line from the pumps to the center of the rail,looped it ,ran a regulator and then a return line back to the tank. I also removed the in tank fuel filter and run an inline at the rail.My pressures are only around 65-70psi under boost but the side to side difference is much better now. Not sure what really contributed to it since I changed a lot.
Last edited by SICAMG; 12-15-2018 at 09:55 AM.
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12-14-2018, 08:57 PM
#8
MBWorld Fanatic!
I ran dual wide bands and saw the same thing. What I did was run a number 8 steel line from the pumps to the center of the rail,looped it ,ran a regulator and then a return line back to the tank.My pressures are only around 65-70psi under boost but the side to side difference is much better now. Not sure what really contributed to it since I changed a lot.
12-14-2018, 11:52 PM
#9
MBWorld Fanatic!
My understanding was that most of the lean issues over the years were finally attributed to poor fuel pressure from clogged fuel filters and failing pumps drawing too much current. For people with mild to moderate mods at least. Everyone seems pretty on to it with fuel filter maintenance these days.
12-15-2018, 05:10 AM
#11
MBWorld Fanatic!
12-15-2018, 08:00 AM
#12
MBWorld Fanatic!
I'm curious about this. When I had the blower off the first time I noticed the air is concentrated to one side by the noise reduction casting and the rotor design. I also noticed that if I made it a single pass cooler, one side would be colder, always having the incoming water. Not sure what your setup looks like exactly, but is it possible you have an air difference? Either flow or temperature?
12-15-2018, 10:11 AM
#13
MBWorld Fanatic!
I'm curious about this. When I had the blower off the first time I noticed the air is concentrated to one side by the noise reduction casting and the rotor design. I also noticed that if I made it a single pass cooler, one side would be colder, always having the incoming water. Not sure what your setup looks like exactly, but is it possible you have an air difference? Either flow or temperature?
12-15-2018, 10:13 AM
#14
MBWorld Fanatic!
I don't think any one will ever have a problem if you run richer than normal. I am always at 10.5 to 11.1 depending on temps. Am I leaving power on the table ? Sure. Did my engine look perfect inside after 3 years of killing it ....YES !
cnterline your car run's real well.....like beyond most anyone so your AFR must be perfect for your engine to live through every pass !
I also wonder if your car would start to go a little leaner if you did a 1/2 mile event where more heat is being accumulated over a longer period of time. That's the boat I am in.
cnterline your car run's real well.....like beyond most anyone so your AFR must be perfect for your engine to live through every pass !
I also wonder if your car would start to go a little leaner if you did a 1/2 mile event where more heat is being accumulated over a longer period of time. That's the boat I am in.
