I just noticed where it says the Portfueler is for "Stages IV and V" on hahn's website and I know I'm not up that high so this gets my hopes up...do I actually need the Portfueler with the Stage 2 Hahn turbo kit?
Here's a shortened list of what has been done to the engine:
Eagle Rods
Wiseco pistons .040 over
Crower stage 2 cams
stock cam gears
Dynopak "high performance" clutch
Unorthodox lightened UDP
Topline lifters & rockers
3-angle valve job
stock crank was reconditioned at the local machine shop


Then I'm adding the 20g Hahn turbo and FMIC as soon as I get the money for things like fuel management (which I may not need?), turbo timer, and boost controller...

How will my engine run if I don't have the Portfueler but add the 20g turbo?

At the very least, you will need a Walbro 255lph High Pressure fuel pump and rising rate fuel pressure regulator (FMU, SMFU).

Try some searching around on those. Next step up is either the Portfueler or MSnS.

Oh ya the Walbro 255 fuel pump is in the works....

I've been wondering for a long time now...what does SFMU stand for? And now FMU??

Woudl the AEM fuel pressure regulator work well for my needs?
Am I going to need larger than stock fuel injectors? I read some things around here that leads me to think maybe? lol and if I do, how big like 450cc's? 410cc's? 490cc's?

Thanks a lot man...

Originally posted by kevox
Oh ya the Walbro 255 fuel pump is in the works.... I've been wondering for a long time now...what does SFMU stand for? And now FMU?? Woudl the AEM fuel pressure regulator work well for my needs? Am I going to need larger than stock fuel injectors? I read some things around here that leads me to think maybe? lol and if I do, how big like 450cc's? 410cc's? 490cc's? Thanks a lot man...

Try some searching because your questions are fairly easy to answer and common questions.

SFMU=SUPER Fuel Management Unit

FMU=Fuel Management Unit

AEM FPR=No

Larger than stock fuel injectors=only if you really plan on running more than 8 lb of boost and are built. Or if you want your fuel pump to last longer.

If you get larger injectors, the FMU is no longer an option and you have to get an SFMU or better to run them.

Originally posted by totaleclipse_05 Try some searching because your questions are fairly easy to answer and common questions. SFMU=SUPER Fuel Management Unit FMU=Fuel Management Unit AEM FPR=No Larger than stock fuel injectors=only if you really plan on running more than 8 lb of boost and are built. Or if you want your fuel pump to last longer. If you get larger injectors, the FMU is no longer an option and you have to get an SFMU or better to run them.

Ok so the AEM unit is no good? What FPR would you recommend then?

And I plan on running more than 8psi that's for sure! I want to do 10psi daily and 16psi whenever I'm feeling the need...


BY FMU you are referring to the Walbro pump, aren't you? I've tried searches and always come up dry...

Like he said in an earlier post, an FMU is a rising rate fuel pressure regulator... it has little to do with the fuel pump (i.e. the Walbro).

There are two ways to increase fuel: an electronic method, by increasing the pulsewidth to the injectors (only possible with a standalone system); or a mechanical method which raising the fuel pressure, thus forcing more fuel from the injectors at the same pulsewidth (i.e. an FMU or S-FMU).

The FMU works well enough with the stock injectors and ECU, but you'll need something adjustable for bigger injectors. That's where the S-FMU comes in. You can easily hit 10psi with an S-FMU and 440s or 550s. You can even reach 16psi with some patience and a good tune.


And about the AEM, it's not that it's junk, but it's used in different applications. While an FMU or S-FMU might raise the fuel pressure four to twelve psi for every psi of boost pressure, an AEM or Aeromotive unit raises the fuel pressure just one psi for every psi of boost simply to equalize manifold and fuel pressures.

You'd use an AEM or Aeromotive AFPR with something like Megasquirt or PortFueler. Honestly, in your case, I would recommend PortFueler... tell Hahn exactly which injectors you plan on using, and they'll take out all of the guess work. All you need to do is follow their instructions for the install... no tuning necessary.

I know there are tons of threads on here about FMU's and S-FMU's, so if you can't find those, you'll probably have a hard time tuning too.

Ok, so basically I can't do 16psi without an S-FMU setup....and I'd be wasting my money to get an aftermarket FPR that would boost 4-12psi in pressure because I'd have to swap that out to an FPR that does only 1psi once I got the Portfueler on, correct?

So what about running just 8 psi without the Portfueler to begin with then...what parts would you recommend I get to make that happen besides the fuel pump? Stock injectors and FPR still okay?

Stock injectors, stock FPR and a 12:1 FMU.

Originally posted by VelocitaPaola
Like he said in an earlier post, an FMU is a rising rate fuel pressure regulator... it has little to do with the fuel pump (i.e. the Walbro).

Originally posted by VelocitaPaola
Stock injectors, stock FPR and a 12:1 FMU.

Wait, what?? I thought an FMU was a FPR and an S-FMU was the Portfueler or Megasquirt system? What do I need to attain a 12:1 FMU on stock injectors? Sorry if i'm missing something here but those comments seem to contradict themselves to me:S

Originally posted by kevox

Originally posted by VelocitaPaola Like he said in an earlier post, an FMU is a rising rate fuel pressure regulator... it has little to do with the fuel pump (i.e. the Walbro).

Originally posted by VelocitaPaola Stock injectors, stock FPR and a 12:1 FMU.

Wait, what?? I thought an FMU was a FPR and an S-FMU was the Portfueler or Megasquirt system? What do I need to attain a 12:1 FMU on stock injectors? Sorry if i'm missing something here but those comments seem to contradict themselves to me:S

You really need to do some more research before you purchase a turbo kit. There are litteraly thousands of threads on here that provide more info than you would ever need. Also the wiki on the main page actually has fuel system install instructions. Have you even bothered to look around the site? Search. These questions are beyond basic.

I bought the turbo from a guy who told me I wouldn't need anything but intercooler piping and 450 or 550cc fuel injectors to make it run - I didn't care how it worked all I cared about is that it did work and gave me the 250+hp Hahn Racecraft has proven it to provide.

That being said, the turbo is ALREADY PURCHASED; I'm just trying to round up the last few things that I'm now just learning I need in order to have it installed (no, I am not doing the install myself. I am leaving that to someone far more experienced!)

I have looked around the site, although a little I will admit, and the fact is I don't understand 75% of what I read because in order to understand certain pages you must have a background of basic knowledge on the topic - which I don't have as I basically just started learning about engines this July (I went to a school with 20 students all my life which did NOT have extra classes such as basic mechanics btw...) so rather than spend literally hours searching for these things (cause, again, I'll read them and not know what I'm reading about cause they WILL use terms that almost everybody knows except me so I will then have to embark upoon a sub-search to find out those terms as well - a never ending path it seems...).

So with that being said, will you please just let me know what specific parts I need? It only takes a couple minutes to type down and will save me hours of wild goose chases in the archives so I would REALLY appreciate it, please!

Start reading:
http://www.2gnt.com/index.php?d=Turbo

Originally posted by totaleclipse_05
Start reading: http://www.2gnt.com/index.php?d=Turbo

Alright, I read through some of those articles for a good half hour tonight...some of it was over my head but some of it was helpful.

Referencing this page specifically, http://www.2gnt.com/index.php?d=420a%20Sleeper%20Part%205 it seems that I don't need to replace my stock FPR so much as add a second FPR on the return line, is this what you guys were trying to tell me all along? I thought we were talking about completely replacing the FPR...

It sounds to me like I'm good up to 8psi on a Walbro fuel pump with a 2nd FPR on the return line and stock injectors, correct? I also read up on how to swap the fuel pump out - seems fairly simple, is it a <1hour job like it looks to be?