Welcome to the 2GNT Forum!
Home Site Background Info & Specs Mods & Tech Info CAPS Part Reviews Donate 2GNT Stickers
Search Printer-friendly copy 2 Users in Chat
Top 2GNT Technical Turbo/Nitrous Tech topic #90497
View in linear mode

Subject: "Please Explain SFMU to stubborn friend" Previous topic | Next topic
eclipse7782Oct-09-05 02:09 PM
Member since Dec 14th 2004
215 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90497, "Please Explain SFMU to stubborn friend"


          

I have an SFMU with 440cc injectors and the safc2. I understand the job of the SFMU is to add fuel when it sees boost, for each pound of boost it adds a certain amount of fuel depending on which spring/disc is inside. I understand the safc2 can only lean out your fuel it can not add fuel. My friend swears i don't need the sfmu and i only need the safc2 to tune my fuel. He says my stock regualtor will be able to add fuel. He has an rsx that he turbo'd it has 440cc injectors and the greedy emanage and he has his stock regulator he does not have the sfmu. Can you please explain why he doesnt need an SFMU and i do, so i can tell him he is wrong and i do need an SFMU.
Thank You,
-Brian

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

Replies to this topic
RE: Please Explain SFMU to stubborn friend, normajean, Oct-09-05 03:59 PM, #1
RE: Please Explain SFMU to stubborn friend, eclipse982nrRST, Oct-09-05 04:38 PM, #2
RE: Please Explain SFMU to stubborn friend, thedawg, Oct-10-05 04:24 AM, #3
RE: Please Explain SFMU to stubborn friend, DSMchevy, Oct-11-05 03:35 AM, #4
RE: Please Explain SFMU to stubborn friend, ModeratorCorbin, Oct-10-05 07:08 AM, #5
RE: Please Explain SFMU to stubborn friend, dandv1977, Oct-10-05 07:46 AM, #6
      RE: Please Explain SFMU to stubborn friend, DSMRoadster, Oct-10-05 08:23 AM, #7
           RE: Please Explain SFMU to stubborn friend, Matt_95tgs, Oct-11-05 08:37 AM, #8

normajeanOct-09-05 03:59 PM
Member since Jun 23rd 2005
110 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90499, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 0




          

I might be wrong but I'm pretty sure you stock regulator won't raise your fuel pressure to the level that you need because it wont read any boost. Thats why you need a fmu or an sfmu. And Like you said the safc only leans it down so you'd have no way to increase your pressure.

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

    
eclipse982nrRSTOct-09-05 04:38 PM
Member since Mar 16th 2004
6314 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90501, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 1


          

Originally posted by normajean
I might be wrong but I'm pretty sure you stock regulator won't raise your fuel pressure to the level that you need because it wont read any boost. Thats why you need a fmu or an sfmu. And Like you said the safc only leans it down so you'd have no way to increase your pressure.


correct

-MIKE-

Stroked 2.2L

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

thedawgOct-10-05 04:24 AM
Donating 2GNT member
6287 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90509, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 0


          

Just point out to him that he drives a Honda and therefore knows jack shit.

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

    
DSMchevyOct-11-05 03:35 AM
Member since Sep 25th 2005
33 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90531, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 3


          

Originally posted by thedawg
Just point out to him that he drives a Honda and therefore knows jack shit.


I almosst bought a honda, then I realized that. haha.

big-block Chevys to boosted DSM's; hey if it goes fast, and sounds good, that is all that really matters.

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

ModeratorCorbinOct-10-05 07:08 AM
Donating 2GNT member
2552 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90512, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 0


          

Every car will have a slightly different fuel system. It will use different types of sensors and react differently to abnormal operating conditions. You will need a strategy specific to that car to get the fuel you want without damaging the engine. You could probably get away with 440's and e-manage with injector control harness and auxiliary MAP sensor. An S-FMU is just an easy fix for us.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

    
dandv1977Oct-10-05 07:46 AM
Member since Aug 19th 2002
79 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90513, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 5


          

The safc and the emanage both remove fuel by lowering the map voltage. The emanage can add fuel by providing a ground for the injectors so no voltage is added to the map signal. the safc can only add fuel by increasing the map voltage which you don't want to do. The only way to safely run a safc is to go overboard on fuel supply using a sfmu and then removing fuel using the safc.

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

        
DSMRoadsterOct-10-05 08:23 AM
Donating 2GNT member
3445 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90514, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 6




          

Originally posted by dandv1977
The safc and the emanage both remove fuel by lowering the map voltage. The emanage can add fuel by providing a ground for the injectors so no voltage is added to the map signal. the safc can only add fuel by increasing the map voltage which you don't want to do. The only way to safely run a safc is to go overboard on fuel supply using a sfmu and then removing fuel using the safc.


cut and paste that to him.

intricatelines.com/ -graphics and vinyls

"Tell them of us and say,
For their tomorrow,
We gave our today."
-- The Kohima Epitaph

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

            
Matt_95tgsOct-11-05 08:37 AM
Donating 2GNT member
1246 posts,
Click to send email to this author Click to send private message to this author Click to view this author's profile Click to add this author to your buddy list
#90543, "RE: Please Explain SFMU to stubborn friend"
In response to Reply # 7


          

Don't forget that as you drop the MAP sensor voltage, you also increase your ignition timing as you decrease your fuel delivery. If you use your safc to make alot of fuel correction (especially at WOT) the motor will start pinging.

Matt
1995 Eclipse GS
2.0L, S16g Turbo, 8 Injectors, 26psi

1998 Eclipse GSX
2.3L Stroker, AEM EMS Converted to Speed Density, FP3065 Turbo, 35psi , and so on...

  

Report This Post to Admin Printer-friendly copy | Reply | Reply with quote | Top

Top 2GNT Technical Turbo/Nitrous Tech topic #90497 Previous topic | Next topic
Powered by DCForum+ Version 2.2
Copyright 1997-2005 DCScripts.com, Copyright 2005-2026 2gnt.com
Generated in 0.055 seconds, executing 30 queries.