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How to install a RRFPR (FMU) ?
Posted: Wed Mar 23, 2011 6:00 pm
by CFK
Ok , so I decided to throw on an Aeromotive Rising Rate Fuel Pressure Regulator ( RRFPR or FMU ), 1:1 W/ a bypass.
http://aeromotiveinc.com/products-page/ ... regulator/
In the instructions it indicates you replace the factory unit with this in place thus having it upstream of the injectors. I know I have heard of people leaving the factory one in place and installing an aftermarket unit downstream of the engine.
Who has done this and how do I do it

It doesn't seem to complicated but I was just looking at the unit and I couldn't see an IN stamped anywhere unless the >Aeromotive symbol> is the arrow ? 4 ports in total, I have a gauge on the front , ones a IN, ones an OUT and I believe the bottom port would be the bypass. So do I simply just install it in the return line and run a seperate bypass line or tap it into the factory Evap line
Any help would be appriciated, Thanks.

Re: How to install a RRFPR (FMU) ?
Posted: Thu Mar 24, 2011 3:42 pm
by CFK
Found from a Galant site:
When looking at our fuel rail setup, the fuel comes into the fuel rail, runs past the injectors and then runs through the FPR and back to the tank. Although this seems ass backwards, that's the way it is.
When you install the kit, you'l keep your existing FPR and install the new one. The new FPR will overide the stock FPR. You'll need to put a "T" connector in the vacumn line to feed both the stock and the new FPR. The rest is pretty easy. Your existing return line will become the inlet line to the new FPR and you'll run a new hose from the outlet of the new FPR back to your fuel rail, where you disconnected the original return line. Then split the vacumn line to both units, and you're good to go.
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He says , from the FPR to your fuel rail. That doesn't make sense to me cause then it would be a closed loop, I think he meant Tank. I hope, or im really confused.
Re: How to install a RRFPR (FMU) ?
Posted: Fri Mar 25, 2011 12:52 am
by WagALeg92
never remove the stock regulator the fmu will override it
Re: How to install a RRFPR (FMU) ?
Posted: Fri Mar 25, 2011 1:23 am
by beatersubi
Seems like a good enough time to do parallel fuel rails.
Re: How to install a RRFPR (FMU) ?
Posted: Fri Mar 25, 2011 5:06 am
by CFK
Alright well after much more research I have figured out that I am leaving the factory FPR and that I will be installing it in the return line, but still can't figure out what to do with the bypass line, if I have to run a seperate line back to the tank ?
beatersubi wrote:Seems like a good enough time to do parallel fuel rails.
I don't know about that, I can't even figure out how to install this thing properly. Let alone getting fancy with it.
Then there's the matter of the restricting valve, I guess you just install it in the Boost/Vacuum sensing line to restrict if your running to rich.
There must be someone on the forum who has installed one ? I know Dougles Vincent has but he hasn't posted here in almost a month.
Re: How to install a RRFPR (FMU) ?
Posted: Sat Mar 26, 2011 2:30 am
by beatersubi
CFK wrote:
I don't know about that, I can't even figure out how to install this thing properly. Let alone getting fancy with it.
That would actually simplify the system quite a bit.
A tee off of the supply line, a supply line from that tee to each rail, a return line from each rail to the regulator, and a line from the regulator back to the tank.
You could get rid of the tangle of stock cross-over lines and get equal fuel flow in each rail all in one shot.
If I could find my 'easy' button, I'd let you borrow it.
Re: How to install a RRFPR (FMU) ?
Posted: Sat Mar 26, 2011 3:33 am
by WagALeg92
geese if you cant figure out how to install this thing how the hell are you gonna figure out how to tune it
Re: How to install a RRFPR (FMU) ?
Posted: Sat Mar 26, 2011 7:58 am
by CFK
beatersubi wrote:CFK wrote:
I don't know about that, I can't even figure out how to install this thing properly. Let alone getting fancy with it.
That would actually simplify the system quite a bit.
A tee off of the supply line, a supply line from that tee to each rail, a return line from each rail to the regulator, and a line from the regulator back to the tank.
You could get rid of the tangle of stock cross-over lines and get equal fuel flow in each rail all in one shot.
If I could find my 'easy' button, I'd let you borrow it.
Alright, that makes perfect sense. Im obviously just gonna keep searching and find out everything I need to know before installing and tuning this. Haven't looked into much more since I thought I'd take a break from the bay and start the bodywork. Thanks, I appreciate the help
WagALeg92 wrote:geese if you cant figure out how to install this thing how the hell are you gonna figure out how to tune it
Awesome, Thanks for the actual advice and sharing your knowledge. You completely cleared this matter up. Dick.
Re: How to install a RRFPR (FMU) ?
Posted: Sat Mar 26, 2011 8:14 am
by mike-tracy
WagALeg92 wrote:geese if you cant figure out how to install this thing how the hell are you gonna figure out how to tune it
We're all here to learn, if everyone knew everything there'd be no reason to have technical discussion part of this forum.
Re: How to install a RRFPR (FMU) ?
Posted: Sat Mar 26, 2011 9:33 am
by kimokalihi
Yeah that was pretty cold.
Re: How to install a RRFPR (FMU) ?
Posted: Mon Mar 28, 2011 6:57 pm
by Legacy777
Before you go ahead and install this, from what I read on their site this unit will do exactly the same thing as the stock fuel pressure regulator. The stock regulator is a one-to-one FPR, and does the same thing this Aeromotive FPR will. Unless you are having problems with the stock FPR, there's no reason to replace it with this one.
If you need more fuel, you would need to get a rising rate, 2:1, 3:1, etc. so you get more fuel only on boost, but still retain the stock fuel pressure for off-boost driving. The one you listed above is not a rising rate FPR. Personally, I don't feel a RRFPR is the way to go if you need more fuel. It does provide a band-aid approach if you don't want to get a larger flowing fuel pump and/or don't want to upgrade injectors & engine management.
Re: How to install a RRFPR (FMU) ?
Posted: Mon Mar 28, 2011 8:50 pm
by CFK

Well that sucks. Serves me right for being so impatient and bidding on it before fully researching it fully. Hopefully I can use it for the Jetta, even though Im going standalone and not trying to avoid EM as I am on this car.
Guess they fooled me into thinking it was a RR unit. On there site:
• Fuel pressure rises on a 1:1 ratio when referencing boost.
Same as stock either way I guess.
The other thing it states that I didn't see and doesn't say in the instruction manual :
Note: (Requires a return line to be installed from the bottom of the regulator to the top of the tank.)
One of the only posts on this site that I did find by Dougles Vincent did stated that he used a 3:1 unit.
Another hard lesson

Well, guess I will just forget about this thing and run low boost until I can afford and find a decent EM or piggyback unit. I hope there is a RobTune EJ22T solution that comes in the near future, as I haven't really heard of any decent options besides getting full standalone set-up which is way out of my budget at this point.
Thanks Again Josh.
