need afpr, what one?

[Carter_95RS]

When I put in my walbro 255hp pump, the car began to stutter and fall on its face making me believe that it got to much fuel because when I had the stock pump in(and still do) the car runs fine. So in order to run my 255 I need a stronger afpr. Should I get a standard 1:1 and continue to use the 12:1 fmu or a rising rate 1:1 regluator?

 

[tragdor]

I'm pretty happy with my FuelLab 515 unit from Slowboy Racing. If I did it again, I might pick it up from somewhere else though as they offered me a great deal, but at the expense of plenty of aggravation through poor communication. It's a nice piece though.

 

[Carter_95RS]

Is that a standard 1:1or a rising rate?

 

[Oliver@Slowboy]

Aeromotive 13109.

 

[akira235]

if you have a turbo you NEED a 1:1 rising rate afpr. It is called that because the fuel pressure rises at a 1:1 ratio with the manifold pressure.

 

[Carter_95RS]

I currently have a 12:1fmu, which is my rising rate regluator. Oliver, will that regulator be used solely with out the fmu or in conjunction with it?

 

[ramsack]

I don't see how a FMU and AFPR would play nice with each other at all, because they are the same thing, just different rise rates. I would be looking into getting a 1:1 AFPR to replace the FMU and using something like MegaSquirt to tune properly. You're limited with 12:1 because you run out of pump volume pretty quick because of needing more pressure. Plus you don't gain volume through the injectors as nicely over running them by that much pressure.

 

[SBR Joe]

I don't see how a FMU and AFPR would play nice with each other at all, because they are the same thing, just different rise rates. I would be looking into getting a 1:1 AFPR to replace the FMU and using something like MegaSquirt to tune properly. You're limited with 12:1 because you run out of pump volume pretty quick because of needing more pressure. Plus you don't gain volume through the injectors as nicely over running them by that much pressure.

They would play about as nice with each other as a KKK member at a black panther party!

FMUs suck, too much compensation, very hard to tune. Go with a 1:1 FPR and enjoy life more.

 

[VelocitàPaola]

They would play about as nice with each other as a KKK member at a black panther party!

FMUs suck, too much compensation, very hard to tune. Go with a 1:1 FPR and enjoy life more.

Right, but it's not as simple as replacing the FMU with the AFPR. As ramsack said, if he gets rid of the FMU he will also need a way to tune, like MegaSquirt.

 

[Slowboy]

Right, but it's not as simple as replacing the FMU with the AFPR. As ramsack said, if he gets rid of the FMU he will also need a way to tune, like MegaSquirt.

I would suggest a way to tune for any car going from NA to forced induction and not rely on a 12:1 FMU.... If you can afford the kit, and want the car to perform properly - spend some bucks on a proper way to tune the car, get it on a dyno, and ditch the FMU.

The reason I say this is becuase I did not see cost come up as an issue anywhere, and the 420A is a very capable platform - I just like seeing people doing things right if they have the means to.

OP - good luck with the car, stay after it!

 

[Carter_95RS]

Hopefully this winter ill be installing megasquirt and I've been looking into doing a bottom end build, still researching a good setup for my application. I have a pos 99 neon I bought for the motor. So it looks like the consensus is saying ditch the fmu for something tuneable. What would be the ideal setup, aside from msns since I can't install that while I'm still dding the car? I hear an sfmu is tunable, but not easily or desirable.

 

[ramsack]

You can use ANY EMS but megasquirt is the budget with the biggest learning curve, and cheapest. It is open source and is expanding in capability all the time.

 

[Carter_95RS]

Megasquirt seems to be the most popular ems for 420a Turbo cars around here, probably due Do price but I haven't heard anything bad about it either. Learning the interface will be the hard part for me.

 

[ramsack]

People are also not pricks in the MS community and will share maps and help you. It's like Linux vs. Windows, AEM and big name stuff being Windows.

 

[LD25Delta9]

Oye vay! You know I have TunerStudioMS and all the related literature. right? Beyond that, there is something wrong somewhere in your fuel system. With an FMU, if everything is working properly, you should be able to pull like a freight train until you hit 8lbs. With the way your car acts under boost, there is something just not right. We need to do a leak down and boost leak test to find your culprits....

 

[ramsack]

He changed his fuel pump, he is experiencing overrun. An FMU is a problem in the first place, and then throw inconsistent overrun into the mix and the car will run like poop. Consider this. Just for simple math I'll use simpler numbers. You have a 10:1 FMU and you run 40 psi of base pressure. When you boost 8 psi you are requiring 120 psi from a fuel pump. You are also expecting small injectors to spray a crapload of fuel and atomize it correctly too. At 120 psi the fuel pump will also barely flow anything. This is why it's best to always just use injectors at their rated base pressure and not cheap out by throwing more pressure at them and expect them to perform well.

It's not a FMU, it's an FPR with a 12:1 rise rate. Fuel management unit makes it sound like it does more than it does. An ECU is what is supposed to control fuel, not a pressure regulator.

 

[Carter_95RS]

adam, my car runs perfectly fine, with thestock pump, now with the walbro my fpr is over ran at idle. I just don't want to be running on the stock pump, that just doesn't sound good. And when megasquirt comes, you'll be receiving a phone call adam. And who knows, maybe another free turbo?

 

[LD25Delta9]

It just seems odd that you have the same setup as me but I have the walbro and I haven't had any issues to speak of....that I want to.

 

[Carter_95RS]

i also have the early fuel system, yours is the 96+( i think). i bet if i got a standard regualtor with a gauge, set it to 43.5 and called it a day it would work. it would be basically the same idea as the stock regulator, just able to hold the pressure and then still have the 12:1 as my rising regulator. I'll just have to remove the stock one, and get an adapter for the fuel rail, then it should be good...hopefully.

 

[LD25Delta9]

You might as well get an aftermarket rail then.

 

[Locke]

If you replace your FPR with a AFPR and intend on keeping with the FMU, do not hook the vacuum/boost reference to the AFPR. This will allow it to remain static, as the factory FPR does. Set it at 50psi, as this is the factory spec. Setting it to 43.5 will cause it to run lean.

A properly functioning 2gnt FPR will not overrun with a 255. Inspect the return for obstructions. Do not overlook the fittings on the FMU as a possible obstruction either. If it is an eBay FMU, the fittings could be too small.

 

[Carter_95RS]

The FMU is an OBX fmu, i can post pics if needed.

i was doing some searching on the Aeromotive 13109 and it has a -6an inlet/outlet so if i were to get that i'd need an adapter like this, or a new fuel rail, correct?

http://www.cimotorsports.net/motor-sport-products/ci-6an-fuel-rail-inlet-fitting.html

would it be better to go ahead and replace the fuel rail with something more free flowing now aswell?

 

[Carter_95RS]

I finally have all of my parts here (aeromotive 13109 and the extreme psi install kit) and I got under the hood to remove the stock fpr and replace it with the aeromotive but I couldn't find it on the end of my rail. According to one of the tech articles its on the end but I have the early fuel system. I read my haynes manuel and it made it sound like it is integrated into the rail? Do I need to change rails for this to work or how could I install this bypassing my stock fpr?

 

[tec_41]

2GNT.com - How_to_Disable_the_95_fuel_regulator <--A little DIY fix to disable the 95 regulator. It should be about the size of a half dollar coin with a vacuum line going to it on the passenger side above the intake manifold.

 

[Carter_95RS]

so its integrated into the rail and needs to be cut off? once its cut do i keep the part that slides into the rail origionally to "cap" it off then add my afpr somewhere else down the line, i'm a little bit confused as to what to do here.