Fuel Management - Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum > Ford Focus Tech Discussions > General Forced Induction

General Forced Induction The place to chat about turbochargers, superchargers nitrous systems and custom engine fabrications.

Search This Forum | Image Search | Advanced Search    
FocusFest FocusFanatics Merchandise

Reply




 
LinkBack Thread Tools Display Modes
Old 03-17-2004, 12:51 PM   #1
Focus Enthusiast
 
Join Date: Mar 2004
Fan#: 4589
Location: Syracuse, NY
What I Drive: 2001 Twilight Blue ZX3

Posts: 303
FF Reputation: 1 TryToFocus Good Standing Member
Buy-Sell-Trade Rating: (0)
Unhappy Fuel Management

Can somebody please explain exactly how aftermarket fuel management works on the Zetec? I've seen examples of turbo Zetecs with the stock ECU, and I don't see how this would work. I'm new to this, so here's my understanding (please tell me if I'm wrong).

As we raise the boost level, the MAF will see more and more air moving past it. That's fine up to a point, but when the MAF gets pegged at its maximum reading, the ECU will not recognize the extra airflow and the mixture will lean out. So we install a recalibrated MAF and now we can flow a lot more air without pegging the meter. Now the fuel injectors can't keep up, so we replace them with larger ones (and calibrate the MAF to the new injectors). Now we've got more airflow potential and more fuel flow potential, and everything's hunky-dory.

BUT the stock ECU will try to use the stoichiometric air/fuel ratio, which will cause detonation in a turbocharged engine, right? We need to make the mixture richer, but changing the calibration of the MAF won't help, because the ECU will simply reduce the fuel flow by pulsing the injectors for a shorter duration.

So how on earth do we change the air/fuel ratio without overriding the stock ECU? It seems like you would need a "trick" oxygen sensor to fool the ECU into thinking that the mixture is leaner than it actually is (I'm sure that can't be right, since I've never even heard of it).

Needless to say, I'm very confused.


__________________
2001 Twilight Blue ZX3 - turbo, Quaife, etc.
TryToFocus is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 03-17-2004, 08:52 PM   #2
Focus Fanatic
 
EuroZX3's Avatar
 
Join Date: Jun 2003
Fan#: 39
Location: Denver, CO
What I Drive: 05 Black Scion TC

Posts: 3,861
FF Reputation: 1 EuroZX3 Good Standing Member
Buy-Sell-Trade Rating: (7)
u cant. i dont know of any turbo foci running well with the stock ecu. maybe a reflash, but definately not the stock ecu. youd be boosting with 87 oct gas then. can u say "detonation"?

anyway, your right about the MAF & Injectors. but a full engine management for the fociis aka MIC which is Maf.... Injectors... and importanty, the Chip. For a turbo to run properly it definately needs to be tuned. otherwise ur just forcin air in that u cant burn right. hope this helps

also things like the apexi AFC dont work because our ECU will eventually learn around it.
__________________
Quote:
Originally posted by darkpuppet
needs more cowbell
EuroZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2004, 11:09 AM   #3
Focus Enthusiast
 
Join Date: Mar 2004
Fan#: 4589
Location: Syracuse, NY
What I Drive: 2001 Twilight Blue ZX3

Posts: 303
FF Reputation: 1 TryToFocus Good Standing Member
Buy-Sell-Trade Rating: (0)
Thanks for the help - I'm glad to know I'm not crazy. I figured there was no way to run a turbo without a chip (unless you like putting holes in your pistons).

BTW- did you see the 26 views and zero replies and take pity on me?

Thanks again.

-Chris
__________________
2001 Twilight Blue ZX3 - turbo, Quaife, etc.
TryToFocus is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2004, 12:28 PM   #4
Focus Fanatic
 
EuroZX3's Avatar
 
Join Date: Jun 2003
Fan#: 39
Location: Denver, CO
What I Drive: 05 Black Scion TC

Posts: 3,861
FF Reputation: 1 EuroZX3 Good Standing Member
Buy-Sell-Trade Rating: (7)
well a lot of people might not have been able to answer this question. engine management isnt somethin u know how it works like an intake. there are a few people that could answer this a lot more detailed than i. but if u really wanna know about it, pick up a copy of maximum boost mr bell
__________________
Quote:
Originally posted by darkpuppet
needs more cowbell
EuroZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2004, 01:31 PM   #5
Focus Enthusiast
 
Join Date: Mar 2004
Fan#: 4589
Location: Syracuse, NY
What I Drive: 2001 Twilight Blue ZX3

Posts: 303
FF Reputation: 1 TryToFocus Good Standing Member
Buy-Sell-Trade Rating: (0)
Yeah, I figured that my question was too specific for most people. Thanks for the book tip - I think I'll add it to my next Amazon/Toolcrib order.
__________________
2001 Twilight Blue ZX3 - turbo, Quaife, etc.
TryToFocus is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2004, 08:03 PM   #6
Focus Fanatic
 
EuroZX3's Avatar
 
Join Date: Jun 2003
Fan#: 39
Location: Denver, CO
What I Drive: 05 Black Scion TC

Posts: 3,861
FF Reputation: 1 EuroZX3 Good Standing Member
Buy-Sell-Trade Rating: (7)
nice let me know what you think. its a great book, u will learn a ton form it. i havent even finished mine. about 300 pages alllllllll on turbos and fuel mapping and all that
__________________
Quote:
Originally posted by darkpuppet
needs more cowbell
EuroZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-19-2004, 02:42 AM   #7
Focus Addict
 
SceviourZX3's Avatar
 
Join Date: Sep 2003
Fan#: 438
Location: NL, Canada
What I Drive: '00 ZX3 CD Silver

Posts: 697
FF Reputation: 1 SceviourZX3 Good Standing Member
Buy-Sell-Trade Rating: (0)
now im putting taking over hahaha, i've posted before never got a exact answer? how much boost for how long can the focus take? to get it tuned right i gotta drive 750 miles, so i which would be better, i wanna tune to run 10-12 lbs of boost, would i be better off using 36lb injectors or 42lbs injectors? just wnat to know. and would i be able to make the 750 mile trip running say 1-2 psi?
__________________
Nick Sceviour

2000 Focus ZX3

T3/t03 Airsearch turbo, Custom Manifold,Downpipe,intercooler piping, Spearco Intercooler, Greddy Type-S BOV,Turbonetics Delta gate 35mm,Stainless Oil lines/fittings, FC 65mm TB, Ported 00 intake manifold, Port/Polished head, Rage Adj Camgears, Esslinger Undedrive Pulley, SVT Pedals, Short Shifter, KYB GR-2 Struts, AR 5 Spoke Chromies,Ventus Rubber, Tein Springs,Xenon bodykit, Hella Headlight conversion, kaminari Carbon Fiber Hood, Kaminari Rear Wing, Shorty Billet Antenna
SceviourZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-19-2004, 11:24 AM   #8
Focus Enthusiast
 
Join Date: Mar 2004
Fan#: 4589
Location: Syracuse, NY
What I Drive: 2001 Twilight Blue ZX3

Posts: 303
FF Reputation: 1 TryToFocus Good Standing Member
Buy-Sell-Trade Rating: (0)
Hey, no hijacking my thread!

I'm very inexperienced, so take this with a grain of salt:

At 10-12 psi, my gut says you'll want 42# injectors. Get a copy of Richard Holdener's book. It won't give you step-by-step instructions, but it's got a TON of dyno runs so you'll be able to get a good idea of what size injectors are needed for a given power output, as well as what power you can safely achieve with the stock fuel pump, etc. BTW that book is also where I learned that the stock throttle body is NOT a restriction for a turbo motor in the low-200 whp range. That book has a LOT of typos and misplaced info, so you've got to read it carefully to understand what Holdener is talking about, but itís worth the trouble.

At 10-12 psi, you might want to start thinking about stronger engine internals, and definitely add a Quaife/Torsen along with a new clutch and, ideally, an aluminum flywheel.

As for running with 1-2 lbs of boost, I don't know, but why not just bypass the turbo entirely? I'm guessing that the waste gate can't do this, so then why not fabricate a section of exhaust pipe to take the turbo's place, and attach a temporary air intake to the intake manifold?

Got a friend with a full-size truck or SUV? Buy a towing bar and haul the Focus to the tuners. Just make sure to leave it in neutral.
__________________
2001 Twilight Blue ZX3 - turbo, Quaife, etc.
TryToFocus is offline  
    Reply With Quote Quick reply to this message
Old 03-19-2004, 12:37 PM   #9
Focus Addict
 
SceviourZX3's Avatar
 
Join Date: Sep 2003
Fan#: 438
Location: NL, Canada
What I Drive: '00 ZX3 CD Silver

Posts: 697
FF Reputation: 1 SceviourZX3 Good Standing Member
Buy-Sell-Trade Rating: (0)
well i will be getting a torsen t2 and the 4.06 gear ratio and i fiound a nice spec clutch at cfm.com. btw stock interals are good for a while yet.
__________________
Nick Sceviour

2000 Focus ZX3

T3/t03 Airsearch turbo, Custom Manifold,Downpipe,intercooler piping, Spearco Intercooler, Greddy Type-S BOV,Turbonetics Delta gate 35mm,Stainless Oil lines/fittings, FC 65mm TB, Ported 00 intake manifold, Port/Polished head, Rage Adj Camgears, Esslinger Undedrive Pulley, SVT Pedals, Short Shifter, KYB GR-2 Struts, AR 5 Spoke Chromies,Ventus Rubber, Tein Springs,Xenon bodykit, Hella Headlight conversion, kaminari Carbon Fiber Hood, Kaminari Rear Wing, Shorty Billet Antenna
SceviourZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-19-2004, 09:20 PM   #10
Focus Fanatic
 
EuroZX3's Avatar
 
Join Date: Jun 2003
Fan#: 39
Location: Denver, CO
What I Drive: 05 Black Scion TC

Posts: 3,861
FF Reputation: 1 EuroZX3 Good Standing Member
Buy-Sell-Trade Rating: (7)
well run good gas and get an i/c and u should be ok with 10.
__________________
Quote:
Originally posted by darkpuppet
needs more cowbell
EuroZX3 is offline  
    Reply With Quote Quick reply to this message
Reply

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Help! 2000 Focus - no fuel - need wiring diagram thebigreddog! General Technical Chat 7 09-21-2013 09:19 AM
Need help with this code. 9318 DomestikZx3 General Technical Chat 17 07-11-2012 09:59 AM
Turbo ZX3 vs. B16A CRX ZX3_Tun3r General Forced Induction 25 04-28-2008 08:22 PM
Dissapering fuel??????? jeepinbanditrider General Technical Chat 15 06-20-2007 04:51 PM
info needed codes read today DomestikZx3 General Technical Chat 3 11-02-2005 06:43 PM


All times are GMT -5. The time now is 09:29 AM.


Copyright 2002-2015 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Mazda CX-3, Audi S3, Mazda MX-5 Miata and Acura TLX. You can find all Ford Focus, Focus ST and Focus RS related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. If you own other makes have a look at Challenger Hellcat Forum, Charger Hellcat Forum, Cadillac ATS-V Forum, Cadillac ATS Forum, Cadillac CTS-V Forum, Lexus RC-F Forum, Lexus GS-F Forum, Mercedes GLA Forum, Mercedes GLE Forum, Civic Type-R Forum and Volvo XC90 Forum.





Search Engine Optimization by vBSEO 3.6.1