Hold On

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

jorj7

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

Koenig-Specials 928

So you're running a straight hose at the back and a reg in front?

jorj7

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

Ducman82

As long as the fuel goes in the fuel rails direct from the pump then thru the bypass style regulator back to the tank. you should do just fine. ( pretty sure that is a bypass style regulator)

Tony

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"

123quattro

If you end up getting Sharktuned throw that rising rate regulator in the trash can...

z driver 88t

Can't Sharktune an '83 L-Jet, correct? If so I would pick one up for my '84.

Koenig-Specials 928

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)

Hold On

Correct No sharktune on an 83 L-Jet

jorj7

I don't know if you'll need to sharktune if you remove the dampers, I did, but I have a lot of other things going on. As for having the FPR in front, I guess it depends on where the fuel feeds into the fuel rail. The feed should go into the rails first, then to the FPR. On a stock S4 the fuel feeds the front of the fuel rail and exits out the back. But that could change if someone does custom fuel lines.

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

Koenig-Specials 928

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

victor25

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

Koenig-Specials 928

Can the guys who have removed theirs comment on that revelation?

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

hacker-pschorr

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.