Fuel System question for boosted cars
#1
Fuel System question for boosted cars
Im currently running a 928MS S/C setup with a BEGI rising rate fuel pressure regulator on a 83 16V 4.7L.
My question is Do I really need 3 pressure regulators ? Can I eliminate the two regulators at the back of engine and just run the single BEGI unit?
Under boost, the BEGI unit will produce upwards of 70PSI of fuel pressure which I think would overwhelm the stock unit diaphrams and cause leaks.
Any input on this is appreciated. Thanks. Kevin
My question is Do I really need 3 pressure regulators ? Can I eliminate the two regulators at the back of engine and just run the single BEGI unit?
Under boost, the BEGI unit will produce upwards of 70PSI of fuel pressure which I think would overwhelm the stock unit diaphrams and cause leaks.
Any input on this is appreciated. Thanks. Kevin
Last edited by Hold On; 08-27-2013 at 04:02 PM.
#2
I assume you're talking about the fuel dampeners. I took them off my car and only run a fuel pressure regulator at the back.
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
#4
No, I run the hose(s) straight into the front:
and have the fuel pressure regulator at the rear:
If you have it at the front, the fuel rails would not get enough fuel, as the fuel pressure regulates the pressure in, and what comes out of it is the excess fuel/pressure.
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
and have the fuel pressure regulator at the rear:
If you have it at the front, the fuel rails would not get enough fuel, as the fuel pressure regulates the pressure in, and what comes out of it is the excess fuel/pressure.
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
#6
Stock dampers.. stock fuel pressure ..42lb injectors..044 fuel pump....and above all a Sharktune!
If you are running those increased pressures be sure your fuel lines are "fresh"
If you are running those increased pressures be sure your fuel lines are "fresh"
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#9
Thanks for all the responses. Yes, all new hoses.
Do I need a sharktune if I remove both dampers?
Also, I asked the question about the front placement of the FPR based on this photo
(another RL member's car....please allow me to use it for illustration purposes)
Do I need a sharktune if I remove both dampers?
Also, I asked the question about the front placement of the FPR based on this photo
(another RL member's car....please allow me to use it for illustration purposes)
Last edited by Koenig-Specials 928; 09-03-2013 at 01:17 PM. Reason: correction
#11
Thanks for all the responses. Yes, all new hoses.
Do I need a sharktune if I remove both dampers?
Also, I asked the question about the front placement of the FPR based on this photo
(another RL member's car....please allow me to use it for illustration purposes)
Attachment 758543
Do I need a sharktune if I remove both dampers?
Also, I asked the question about the front placement of the FPR based on this photo
(another RL member's car....please allow me to use it for illustration purposes)
Attachment 758543
Here is a diagram of my current fuel system, which may help:
George
90 S4 Grand Prix White (Murf #5)
94 GTS 5-Speed Midnight Blue
06 Cayenne S Havanna/Sand Beige (PASM)
http://928.jorj7.com
#12
Thank you guys. You're an excellent teacher George. . Thanks for the lessons. I understand exactly what I need to do to 'clean up' the engine compartment as others have done. Cheers!
Fred
Fred
Last edited by Koenig-Specials 928; 09-03-2013 at 03:13 PM. Reason: add more
#13
If you remove all the dampers, you will get a thumping sound that will echo through the car. Because these cars batch fire the injectors (meaning all at once) a pressure wave travels back up the fuel line to the fuel pump and tank. leave at least the front one on
#14
I have owned several V8 FI cars without dampers and have never experienced any thumping sounds (of course I am not sure they were batch types - MBZ 450SL, Audi V8, Mustang, Sm block Camaro).
Thanks
#15
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1. Ditch the BEGI - they suck, the VORTEC FMU is much more reliable.
2. With L-Jet, the fast way is to replace one of the regulators is with a dampener from an 85/86. It's a direct bolt in.
Your car should run 100% stock until boost comes on. This means no need for an adjustable regulator, just the stock one is needed and an FMU dialed in for the amount of boots.
I would so pick up boost directly from the plenum, not the throttle body, to "feed" the FMU.
I would also have a boost gauge tee'd into the same line.
This is an "early warning" system that your FMU is not seeing boost if the gauge is reading zero.
2. With L-Jet, the fast way is to replace one of the regulators is with a dampener from an 85/86. It's a direct bolt in.
Your car should run 100% stock until boost comes on. This means no need for an adjustable regulator, just the stock one is needed and an FMU dialed in for the amount of boots.
I would so pick up boost directly from the plenum, not the throttle body, to "feed" the FMU.
I would also have a boost gauge tee'd into the same line.
This is an "early warning" system that your FMU is not seeing boost if the gauge is reading zero.