Svx Fpr

Unsung Boxer · 05-22-2004, 01:46 PM

So, I have a WRX fuel pump and EJ22t injectors, 10-12lbs boost, been using stock FPR...

u guys think this is a problem? Should i get an SVX FPR? If so, how much are they?

-Jake

* Registered users of the site do not see these ads.

benjaminetanyahoo · 05-22-2004, 02:02 PM

I'm looking for one too. subaruparts.com has them for 98 bucks for the same part number I got from the dealership, but it might not be exactly for a SVX. Good luck if you find one hook a brother up I need to get rid of this vortech

8Complex · 05-22-2004, 03:57 PM

www.car-parts.com -- got mine for $35 off a junk car, and as far as I know, it's still working great for the person that bought it from me.

Unsung Boxer · 05-22-2004, 07:56 PM

but really how necessary is it? Am i losing fuel pressure, or am i starving my injectors using my current setup:

WRX pump
EJ22t injectors
EJ22 na (stock) FPR
10lbs boost
(emanage)

benjaminetanyahoo · 05-22-2004, 08:00 PM

From what I hear if you use a high flow fuel pump like a walbro or what not, the best fuel pressure regulator to get is the svx because the stock one will run rich. That's from Wedge's mouth...

Unsung Boxer · 05-22-2004, 08:06 PM

so what ur saying is that my FPR cannot hold back my WRX pump?

-Jake

benjaminetanyahoo · 05-22-2004, 08:46 PM

That's what I got out of it

Portly · 05-22-2004, 09:22 PM

Just the opposite - your stock FPR is too restrictive. At higher flow rates, the FPR won't let enough fuel through and your line pressure will rise. This is really only a problem at idle/low load, since the injectors are using such a small amount of fuel. All the rest of it needs to pass through the FPR to get back to the fuel tank, and it can't.

FWIW, a friend of mine installed a Walbro pump and his fuel pressure went way up at idle. I happened to have an old FPR off of a 1.8l engine. After some experimentation, we discovered that the old 1.8L FPR worked the same way the SVX one did. My theory is that _all_ the old FPRs worked like the SVX one, and later, Subaru put a stiffer spring in the FPR (or something like that) and this is what caused the problems at high fuel flow rates.

Also, FWIW, I'm running a WRX pump and a stock FPR. No problems, but I've never measured my fuel pressure to see if it's high at idle.

As usual, this went way longer than I intended.

Hope you can make sense of it.

_Jeff

8Complex · 05-23-2004, 01:06 AM

Not sure about the WRX pump without the regulator, but I think pretty much any WRX FPR should work too. Not sure which direction the vacuum line is leaving it's housing, but it shouldn't be too hard to fit a line to it properly to get it to work.

Also, Porter is correct about the description. I've seen a Walbro idle at 45psi, then when partial throttle is hit, it will actually drop pressure as the injectors are using a decent amount of fuel, then will go back up to around 43-45psi at WOT.

scoobyimprza · 05-23-2004, 01:45 AM

I'm using a WRX pump and 280cc injectors on my EJ18T with the stock FPR. At 6 psi and maxing the injectors, my car still seems to run a little too lean. Would a less restrictive FPR be ideal for something like this?

Brent

Portly · 05-23-2004, 08:01 AM

8

It's Portly, not Porter.

scoobyimprza:

A less-restrictive FPR will lower fuel pressure (and lean out a mixture), not raise it. Remember, the FPR creates it's restriction after the fuel has passed the injectors, so the more it restricts, the more pressure the injectors see. In your case, a RRFPR (like the Vortech unit so many turbo kits seem to come with) might be the ticket, as it will raise fuel pressure in proportion to boost, resulting in some extra fuel getting to the injectors. The Cartech FMU/FPR ( http://www.cartech.net/fmu2020.htm ) might work well for you, as it appears to be quite adjustable. However, I have no experience with this unit, so I can't vouch for it's ease of use or reliablity.

And remember, I'm just a Scooby Newbie, so I may not know what I'm talking about.

_Jeff

8Complex · 05-23-2004, 09:22 AM

Quote:

Originally posted by Portly
8

It's Portly, not Porter.

Doh! And I was wondering how much Porter knew technically when I was typing that, too.

Agreed with Portly's method stated above. Get a good baseline pressure, then use an RRFPR to raise from there. The restrictive FPR's aren't very consistent with their pressures, so tuning them would be a pain in the arse.

Pi7467mp · 05-23-2004, 12:26 PM

Ok from personal experience... I had a "modified" FPR for a while, then I bought a used SVX FPR.. my car ran SSOOOOOOO much better.. just get one they are cheap, and can't hurt anything.

Unsung Boxer · 05-23-2004, 01:53 PM

im wondering if this would contribute to my extremely rich idle when car is cold

-Jake

benjaminetanyahoo · 05-23-2004, 02:03 PM

I'm getting one to see if this will fix my rich idle period... I imagine it would, find a used one for less than 75 or so and have at it, can't hurt ya know

Unsung Boxer · 05-23-2004, 06:18 PM

do we have confirmation that the old EJ18 one is the same?

-Jake

Portly · 05-23-2004, 06:50 PM

Jake

I don't know of anyone other than my friend who's tried this. It's still working great for him, but the "body of knowledge" is a bit thin on this one. If you can find one for a song, I'd say go for it. Not sure how old you'll have to go, though. I think the one I gave him was off of a '93.

_Jeff

05-22-2004, 01:46 PM	#1
Unsung Boxer Scooby Specialist Member#: 37196 Join Date: May 2003 Location: WA state	Svx Fpr So, I have a WRX fuel pump and EJ22t injectors, 10-12lbs boost, been using stock FPR... u guys think this is a problem? Should i get an SVX FPR? If so, how much are they? -Jake * Registered users of the site do not see these ads.

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
So is a MY98 rs fpr the same as an SVX fpr?	GregBolby	Normally Aspirated with bolt-on Forced Induction Powertrain	18	09-30-2004 08:50 PM
Is my new SVX FPR bad?	david2z4	Normally Aspirated with bolt-on Forced Induction Powertrain	8	07-23-2002 03:47 PM
Save your self time, frustration, and money and just get a SVX FPR!	Eric SS	Normally Aspirated with bolt-on Forced Induction Powertrain	5	06-16-2002 01:28 PM
HELP! I need SVX FPR today. where in Phoenix can I get one??	Eric SS	South West Impreza Club Forum -- SWIC	2	06-10-2002 01:26 PM
RS-T : SVX FPR swap... fixed the idle pressure problems	8Complex	Normally Aspirated with bolt-on Forced Induction Powertrain	0	06-27-2001 03:12 PM

05-22-2004, 02:02 PM	#2
benjaminetanyahoo * Banned * Member#: 41300 Join Date: Aug 2003 Chapter/Region: Tri-State Location: Midtown West (Lincoln Center) Vehicle: 2000 New York MTA	I'm looking for one too. subaruparts.com has them for 98 bucks for the same part number I got from the dealership, but it might not be exactly for a SVX. Good luck if you find one hook a brother up I need to get rid of this vortech

05-22-2004, 03:57 PM	#3
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 04 FXT Red	www.car-parts.com -- got mine for $35 off a junk car, and as far as I know, it's still working great for the person that bought it from me.

05-22-2004, 07:56 PM	#4
Unsung Boxer Scooby Specialist Member#: 37196 Join Date: May 2003 Location: WA state	but really how necessary is it? Am i losing fuel pressure, or am i starving my injectors using my current setup: WRX pump EJ22t injectors EJ22 na (stock) FPR 10lbs boost (emanage)

05-22-2004, 08:00 PM	#5
benjaminetanyahoo * Banned * Member#: 41300 Join Date: Aug 2003 Chapter/Region: Tri-State Location: Midtown West (Lincoln Center) Vehicle: 2000 New York MTA	From what I hear if you use a high flow fuel pump like a walbro or what not, the best fuel pressure regulator to get is the svx because the stock one will run rich. That's from Wedge's mouth...

05-22-2004, 08:06 PM	#6
Unsung Boxer Scooby Specialist Member#: 37196 Join Date: May 2003 Location: WA state	so what ur saying is that my FPR cannot hold back my WRX pump? -Jake

05-22-2004, 08:46 PM	#7
benjaminetanyahoo * Banned * Member#: 41300 Join Date: Aug 2003 Chapter/Region: Tri-State Location: Midtown West (Lincoln Center) Vehicle: 2000 New York MTA	That's what I got out of it

05-22-2004, 09:22 PM	#8
Portly Scooby Specialist Member#: 1197 Join Date: Apr 2000 Chapter/Region: MWSOC Location: Cedar Rapids, Iowa Vehicle: 1997 Impreza Wagon Mystic Blue Pearl	Just the opposite - your stock FPR is too restrictive. At higher flow rates, the FPR won't let enough fuel through and your line pressure will rise. This is really only a problem at idle/low load, since the injectors are using such a small amount of fuel. All the rest of it needs to pass through the FPR to get back to the fuel tank, and it can't. FWIW, a friend of mine installed a Walbro pump and his fuel pressure went way up at idle. I happened to have an old FPR off of a 1.8l engine. After some experimentation, we discovered that the old 1.8L FPR worked the same way the SVX one did. My theory is that _all_ the old FPRs worked like the SVX one, and later, Subaru put a stiffer spring in the FPR (or something like that) and this is what caused the problems at high fuel flow rates. Also, FWIW, I'm running a WRX pump and a stock FPR. No problems, but I've never measured my fuel pressure to see if it's high at idle. As usual, this went way longer than I intended. Hope you can make sense of it. _Jeff

05-23-2004, 01:06 AM	#9
8Complex Moderator Member#: 922 Join Date: Feb 2000 Chapter/Region: MWSOC Location: Schaumburg, IL Vehicle: 04 FXT Red	Not sure about the WRX pump without the regulator, but I think pretty much any WRX FPR should work too. Not sure which direction the vacuum line is leaving it's housing, but it shouldn't be too hard to fit a line to it properly to get it to work. Also, Porter is correct about the description. I've seen a Walbro idle at 45psi, then when partial throttle is hit, it will actually drop pressure as the injectors are using a decent amount of fuel, then will go back up to around 43-45psi at WOT.

05-23-2004, 01:45 AM	#10
scoobyimprza Scooby Guru Member#: 24956 Join Date: Sep 2002 Chapter/Region: MAIC Location: Littlestown PA Vehicle: 1997 Impreza WRX Steel Blue Mica	I'm using a WRX pump and 280cc injectors on my EJ18T with the stock FPR. At 6 psi and maxing the injectors, my car still seems to run a little too lean. Would a less restrictive FPR be ideal for something like this? Brent

05-23-2004, 08:01 AM	#11
Portly Scooby Specialist Member#: 1197 Join Date: Apr 2000 Chapter/Region: MWSOC Location: Cedar Rapids, Iowa Vehicle: 1997 Impreza Wagon Mystic Blue Pearl	8 It's Portly, not Porter. scoobyimprza: A less-restrictive FPR will lower fuel pressure (and lean out a mixture), not raise it. Remember, the FPR creates it's restriction after the fuel has passed the injectors, so the more it restricts, the more pressure the injectors see. In your case, a RRFPR (like the Vortech unit so many turbo kits seem to come with) might be the ticket, as it will raise fuel pressure in proportion to boost, resulting in some extra fuel getting to the injectors. The Cartech FMU/FPR ( http://www.cartech.net/fmu2020.htm ) might work well for you, as it appears to be quite adjustable. However, I have no experience with this unit, so I can't vouch for it's ease of use or reliablity. And remember, I'm just a Scooby Newbie, so I may not know what I'm talking about. _Jeff

05-23-2004, 12:26 PM	#13
Pi7467mp Scooby Newbie Member#: 19124 Join Date: May 2002 Location: Northern Colorado Vehicle: 2009 Nissan GTR RED Premium	Ok from personal experience... I had a "modified" FPR for a while, then I bought a used SVX FPR.. my car ran SSOOOOOOO much better.. just get one they are cheap, and can't hurt anything.

05-23-2004, 01:53 PM	#14
Unsung Boxer Scooby Specialist Member#: 37196 Join Date: May 2003 Location: WA state	im wondering if this would contribute to my extremely rich idle when car is cold -Jake

05-23-2004, 02:03 PM	#15
benjaminetanyahoo * Banned * Member#: 41300 Join Date: Aug 2003 Chapter/Region: Tri-State Location: Midtown West (Lincoln Center) Vehicle: 2000 New York MTA	I'm getting one to see if this will fix my rich idle period... I imagine it would, find a used one for less than 75 or so and have at it, can't hurt ya know

05-23-2004, 06:18 PM	#16
Unsung Boxer Scooby Specialist Member#: 37196 Join Date: May 2003 Location: WA state	do we have confirmation that the old EJ18 one is the same? -Jake

05-23-2004, 06:50 PM	#17
Portly Scooby Specialist Member#: 1197 Join Date: Apr 2000 Chapter/Region: MWSOC Location: Cedar Rapids, Iowa Vehicle: 1997 Impreza Wagon Mystic Blue Pearl	Jake I don't know of anyone other than my friend who's tried this. It's still working great for him, but the "body of knowledge" is a bit thin on this one. If you can find one for a song, I'd say go for it. Not sure how old you'll have to go, though. I think the one I gave him was off of a '93. _Jeff