Mallory FPR Information
Thread Starter
Weird Cat Man
Joined: Aug 2001
Posts: 2,868
Likes: 3
From: A pale blue dot
Mallory FPR Information
Hello Guys and Gals,
Here is some first hand experience for ya with Mallory fuel pressure regs.
When I set up my 1600s/k2rd rail, I had to trash the factory FPR. I went to my local speed shop place and the guy there recommended a Mallory 4309 which said it was adjustable from 3 to 65 PSI with boost compensation of 1:1 ratio. Sounds good, so I got it.
When I installed it, I found that I had to crank it down pretty much all the way closed just to make 40 PSI at 0 manifold pressure. Hmmm not good. I went for a test drive and found that the boost compensation didn't work for vacuum or for boost. It just stayed at 40 all the dang time. I ended up troubleshooting my fuel pump for a week or so figuring that could be weak... eventually I called the guy back and he had found a new part number that came out somewhat recently that he said might be better.
Went back, swapped the 4309 for a 4305M. Just by looking at it, I had high hopes... much beefier spring inside... larger inlet/return fittings...
Went home, put it on... bingo! The 4305M is working great so far. I have 40 PSI at 0, about 30-32 at idle, and I get around 50-52 at about 11.5 pounds of boost. I still have some more testing to do, but it's dark now and I can't see my fuel pressure gauge in the dark.
Brian
87 TII
93 R1 T04S
Here is some first hand experience for ya with Mallory fuel pressure regs.
When I set up my 1600s/k2rd rail, I had to trash the factory FPR. I went to my local speed shop place and the guy there recommended a Mallory 4309 which said it was adjustable from 3 to 65 PSI with boost compensation of 1:1 ratio. Sounds good, so I got it.
When I installed it, I found that I had to crank it down pretty much all the way closed just to make 40 PSI at 0 manifold pressure. Hmmm not good. I went for a test drive and found that the boost compensation didn't work for vacuum or for boost. It just stayed at 40 all the dang time. I ended up troubleshooting my fuel pump for a week or so figuring that could be weak... eventually I called the guy back and he had found a new part number that came out somewhat recently that he said might be better.
Went back, swapped the 4309 for a 4305M. Just by looking at it, I had high hopes... much beefier spring inside... larger inlet/return fittings...
Went home, put it on... bingo! The 4305M is working great so far. I have 40 PSI at 0, about 30-32 at idle, and I get around 50-52 at about 11.5 pounds of boost. I still have some more testing to do, but it's dark now and I can't see my fuel pressure gauge in the dark.
Brian
87 TII
93 R1 T04S
Thread Starter
Weird Cat Man
Joined: Aug 2001
Posts: 2,868
Likes: 3
From: A pale blue dot
It's got an AN-8 return port.... a gauge port (1/8 NPT???), three 3/8 inch NPT inlet/outlet to injectors, and one AN-8 inlet/outlet to injectors. It also does boost compensation.
I think I paid about 105-110 bucks for it from a local shop here.
Brian
I think I paid about 105-110 bucks for it from a local shop here.
Brian
I just ordered One.
http://www.centuryperformance.com/de...t_id=MAL-4305m
How's yours holding up so far Wargasm?
http://www.centuryperformance.com/de...t_id=MAL-4305m
How's yours holding up so far Wargasm?
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NorCal 7's Co-founder
Joined: Aug 2002
Posts: 4,130
Likes: 5
From: Rocklin, CA
Yeah, he's still on here. Hopefully he'll answer you soon. I know that BDC is using a Mallory FPR as well. Maybe you should PM him. He seems to really like it from what I remember.
Zach
Zach
'Tuna'
Joined: Feb 2001
Posts: 4,637
Likes: 3
From: Miami,Fl,USA
Originally Posted by Wargasm
Hello Guys and Gals,
Here is some first hand experience for ya with Mallory fuel pressure regs.
When I set up my 1600s/k2rd rail, I had to trash the factory FPR. I went to my local speed shop place and the guy there recommended a Mallory 4309 which said it was adjustable from 3 to 65 PSI with boost compensation of 1:1 ratio. Sounds good, so I got it.
When I installed it, I found that I had to crank it down pretty much all the way closed just to make 40 PSI at 0 manifold pressure. Hmmm not good. I went for a test drive and found that the boost compensation didn't work for vacuum or for boost. It just stayed at 40 all the dang time. I ended up troubleshooting my fuel pump for a week or so figuring that could be weak... eventually I called the guy back and he had found a new part number that came out somewhat recently that he said might be better.
Went back, swapped the 4309 for a 4305M. Just by looking at it, I had high hopes... much beefier spring inside... larger inlet/return fittings...
Went home, put it on... bingo! The 4305M is working great so far. I have 40 PSI at 0, about 30-32 at idle, and I get around 50-52 at about 11.5 pounds of boost. I still have some more testing to do, but it's dark now and I can't see my fuel pressure gauge in the dark.
Brian
87 TII
93 R1 T04S
Here is some first hand experience for ya with Mallory fuel pressure regs.
When I set up my 1600s/k2rd rail, I had to trash the factory FPR. I went to my local speed shop place and the guy there recommended a Mallory 4309 which said it was adjustable from 3 to 65 PSI with boost compensation of 1:1 ratio. Sounds good, so I got it.
When I installed it, I found that I had to crank it down pretty much all the way closed just to make 40 PSI at 0 manifold pressure. Hmmm not good. I went for a test drive and found that the boost compensation didn't work for vacuum or for boost. It just stayed at 40 all the dang time. I ended up troubleshooting my fuel pump for a week or so figuring that could be weak... eventually I called the guy back and he had found a new part number that came out somewhat recently that he said might be better.
Went back, swapped the 4309 for a 4305M. Just by looking at it, I had high hopes... much beefier spring inside... larger inlet/return fittings...
Went home, put it on... bingo! The 4305M is working great so far. I have 40 PSI at 0, about 30-32 at idle, and I get around 50-52 at about 11.5 pounds of boost. I still have some more testing to do, but it's dark now and I can't see my fuel pressure gauge in the dark.
Brian
87 TII
93 R1 T04S
I've use that regulator many times before but had durability problems with the diaphram. It works wonderful for carb blow through setups but I didn't like it for use with FI with boost.
Rotary Enthusiast
Joined: Mar 2001
Posts: 1,353
Likes: 9
From: Sydney, Australia
Originally Posted by crispeed
The 4309 comes with three different springs. Did you use the right spring?
I've use that regulator many times before but had durability problems with the diaphram. It works wonderful for carb blow through setups but I didn't like it for use with FI with boost.
I've use that regulator many times before but had durability problems with the diaphram. It works wonderful for carb blow through setups but I didn't like it for use with FI with boost.
had exactly the same problems with them,
i only use magnafuel or SX regs now
Thread Starter
Weird Cat Man
Joined: Aug 2001
Posts: 2,868
Likes: 3
From: A pale blue dot
My 4305M model is still working perfectly and I haven't had to mess with it at all. I don't daily drive the car, so even though it's been on there 3 1/2 years, it sees less actual use than that time would suggest.
I'm running about 36 PSI of fuel pressure at 0 manifold (hose taken off). The 1:1 compensating works fine.... overall, I can't complain about it.
I'm running about 36 PSI of fuel pressure at 0 manifold (hose taken off). The 1:1 compensating works fine.... overall, I can't complain about it.
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