Fuel Pressure Regulator
11-24-07, 12:08 PM
#1
Fuel Pressure Regulator
Does the Mallory fuel pressure regulator that racing beat offers plug right into the existing fuel return line that is on a stock 7? Also it looks like it's only adjustable down to 3 PSI. Has anyone used this regulator with a 45DCOE? Is 3 PSI low enough?
11-24-07, 12:15 PM
#2
3psi should be more than low enough (in fact too low) for most aftermarket carbs. IIRC most aftermarket carbs want 6psi, and more flow than your stock pump can put out, so when people upgrade carbs they ususally upgrade their fuel system at the same time.
For a stock carb, where you want between 2.5-3.5psi, that reg would work at its lowest setting, but most people opt for the Holley 1-4psi FPR since it's more in the range we're looking for.
I use the Holley 1-4psi FPR along with a Mallory Comp 70 fuel pump and one of those 1-10psi gauges that ReSpeed sells (amazingly good gauges). The gauge is worth its weight in gold because until you get a good one you never really know what your fuel pressure is.
Case in point: I bought my first Holley FPR and the shop gave me the wrong one. They gave me the 4.5-9psi one. So I couldn't figure out why I was overpowering my needles and seats and flooding all the time. No manner of adjustment fixed it, but once I threw the gauge on there I understood. I bought the proper regulator and everything went better from there.
As for plumbing the system in, yes in a manner of speaking it will work with your stock setup. You'll have to buy some fuel hose and find a place to mount the FPR, and if it doesn't come with fittings you'll need to buy those, but you won't have to make any major changes to make it work. It's pretty straightforward.
I mounted my FPR on the firewall, so instead of going directly to my carb, the fuel goes from the metal tube at the firewall to my fpr, then from my fpr to my carb.
Jon
For a stock carb, where you want between 2.5-3.5psi, that reg would work at its lowest setting, but most people opt for the Holley 1-4psi FPR since it's more in the range we're looking for.
I use the Holley 1-4psi FPR along with a Mallory Comp 70 fuel pump and one of those 1-10psi gauges that ReSpeed sells (amazingly good gauges). The gauge is worth its weight in gold because until you get a good one you never really know what your fuel pressure is.
Case in point: I bought my first Holley FPR and the shop gave me the wrong one. They gave me the 4.5-9psi one. So I couldn't figure out why I was overpowering my needles and seats and flooding all the time. No manner of adjustment fixed it, but once I threw the gauge on there I understood. I bought the proper regulator and everything went better from there.
As for plumbing the system in, yes in a manner of speaking it will work with your stock setup. You'll have to buy some fuel hose and find a place to mount the FPR, and if it doesn't come with fittings you'll need to buy those, but you won't have to make any major changes to make it work. It's pretty straightforward.
I mounted my FPR on the firewall, so instead of going directly to my carb, the fuel goes from the metal tube at the firewall to my fpr, then from my fpr to my carb.
Jon
11-24-07, 12:30 PM
#3
Lives on the Forum
I did a writeup some time ago on the installation of the Carter fuel pump and Holley pressure regulator. I believe it is in the Archive now, and should give you some ideas on where/how to mount the fpr...
Also, like Viper said, spend the money for a good gauge. Most gauges have something like a 10% error rate, and when you are dealing with 2-3 psi on a 1-20 psi gauge, that's a hell of a lot of error. Yaw did a nice writeup on this, if you want to check his site out.
The gauge from www.re-speed.com is definitely the one to get. Billy did the research and found what we needed for our applications. I have found it indispensible for the tuning of my autocrosser.
Good luck!
Also, like Viper said, spend the money for a good gauge. Most gauges have something like a 10% error rate, and when you are dealing with 2-3 psi on a 1-20 psi gauge, that's a hell of a lot of error. Yaw did a nice writeup on this, if you want to check his site out.
The gauge from www.re-speed.com is definitely the one to get. Billy did the research and found what we needed for our applications. I have found it indispensible for the tuning of my autocrosser.
Good luck!
11-24-07, 12:37 PM
#4
Ya I already have a "re-speed fuel pressure gauge" and a "holley red" fuel pump, just wondering if the mallory regulator from racing beat is a good one since it has the fuel return line and i haven't taken out the return line from the stock setup.
11-25-07, 09:51 PM
#6
With the Holley one you let your carb return line stay exactly as it is. You just place the holley reg in the send line and cap off one of the "out" ports.
Nice and easy setup. I got a "T" for my gauge so that it shows pressure just before the carb inlet, but some people put their gauge on the other side of the Holley. I just wasn't sure that was as accurate as the way I ended up doing it.
Jon
Nice and easy setup. I got a "T" for my gauge so that it shows pressure just before the carb inlet, but some people put their gauge on the other side of the Holley. I just wasn't sure that was as accurate as the way I ended up doing it.
Jon
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