Ported throttle Body - Page 9 - 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 Third Generation > DURATEC Ti-VCT Performance (2012-Current)

DURATEC Ti-VCT Performance (2012-Current) The place to chat about any Duratec 2.0L Ti-VCT engine performance, tuning and exhaust related upgrades.

Search This Forum | Image Search | Advanced Search    
Ford Focus Tire & Wheels FocusFanatics Merchandise

Reply
 
Thread Tools Display Modes
Old 03-06-2014, 08:34 PM   #81
iminhell
C2H5OH
 
iminhell's Avatar
 
Join Date: Jun 2006
Fan#: 36222
Location: Darwin, MN
What I Drive: 2000 & 2001 ZX3's

Posts: 10,717
Points 18,451, Level 86
Points: 18,451, Level: 86 Points: 18,451, Level: 86 Points: 18,451, Level: 86
Level Up 21% Completed
Level up: 21% Level up: 21% Level up: 21%
Forum Activity 8%
Activity: 8% Activity: 8% Activity: 8%
FF Reputation: 49 iminhell Great Standing Member
Buy-Sell-Trade Rating: (4)
Quote:
Originally Posted by goingtoscotland View Post
And you have a complete misunderstanding of fluid dynamics and how they come into play in a restriction

That's static air pressure(at sea level), and has nothing to do with velocity or volume. Not sure where you're even going with that? If you take a throttle body and reduce the size of the venturi you will increase pressure(prior to the venturi), lower pressure IN and after the venturi , increase velocity, and decrease the maximum amount of air that venturi is capable of flowing in whatever measurement you decide to use. Should you increase the size of the venturi you will DECREASE PRESSURE(before the venturi) AND VELOCITY, and INCREASE VOLUME. Higher velocities=lower volume. Smaller opening=higher velocities.

So yes. a larger opening will increase volume, but pressure isn't involved in the way you think it is.

A larger TB on an FI car will net you good gains because it produces WAY more suction than an NA motor.

Where does pressure come from?

Again, you're forgetting variables.
iminhell is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 03-06-2014, 08:44 PM   #82
goingtoscotland
Focus Addict
 
goingtoscotland's Avatar
 
Join Date: Dec 2013
Fan#: 132001
Location: Hull, IA
What I Drive: '14 Tuxedo Black HB, 05 Kawi ZX-10R

Posts: 775
Points 1,954, Level 26
Points: 1,954, Level: 26 Points: 1,954, Level: 26 Points: 1,954, Level: 26
Level Up 54% Completed
Level up: 54% Level up: 54% Level up: 54%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 6 goingtoscotland Good Standing Member
Buy-Sell-Trade Rating: (0)
In this case, pressure has nothing to do with atmospheric pressures. The pressure in this case is suction caused by the vacuum the piston creates on the intake stroke.

I agree with you, yes a larger opening will result in more flow(less air pressure, though), but you don't understand why. That much is clear when you're citing atmospheric pressure as a reason.
goingtoscotland is offline  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 08:46 PM   #83
iminhell
C2H5OH
 
iminhell's Avatar
 
Join Date: Jun 2006
Fan#: 36222
Location: Darwin, MN
What I Drive: 2000 & 2001 ZX3's

Posts: 10,717
Points 18,451, Level 86
Points: 18,451, Level: 86 Points: 18,451, Level: 86 Points: 18,451, Level: 86
Level Up 21% Completed
Level up: 21% Level up: 21% Level up: 21%
Forum Activity 8%
Activity: 8% Activity: 8% Activity: 8%
FF Reputation: 49 iminhell Great Standing Member
Buy-Sell-Trade Rating: (4)
What does a MAF measure?
iminhell is offline  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 08:52 PM   #84
goingtoscotland
Focus Addict
 
goingtoscotland's Avatar
 
Join Date: Dec 2013
Fan#: 132001
Location: Hull, IA
What I Drive: '14 Tuxedo Black HB, 05 Kawi ZX-10R

Posts: 775
Points 1,954, Level 26
Points: 1,954, Level: 26 Points: 1,954, Level: 26 Points: 1,954, Level: 26
Level Up 54% Completed
Level up: 54% Level up: 54% Level up: 54%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 6 goingtoscotland Good Standing Member
Buy-Sell-Trade Rating: (0)
The density of the intake charge, in the middle of the restriction(whether in a flow tube or on the TB itself(rare)) where pressure is the LOWEST.
goingtoscotland is offline  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 08:54 PM   #85
iminhell
C2H5OH
 
iminhell's Avatar
 
Join Date: Jun 2006
Fan#: 36222
Location: Darwin, MN
What I Drive: 2000 & 2001 ZX3's

Posts: 10,717
Points 18,451, Level 86
Points: 18,451, Level: 86 Points: 18,451, Level: 86 Points: 18,451, Level: 86
Level Up 21% Completed
Level up: 21% Level up: 21% Level up: 21%
Forum Activity 8%
Activity: 8% Activity: 8% Activity: 8%
FF Reputation: 49 iminhell Great Standing Member
Buy-Sell-Trade Rating: (4)
I give up.
iminhell is offline  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 08:57 PM   #86
dyn085
That Guy
 
dyn085's Avatar
 
Join Date: Apr 2012
Fan#: 98047
Location: Fayetteville, NC
What I Drive: 2014 FiST/FoST

Posts: 12,332
Points 24,762, Level 95
Points: 24,762, Level: 95 Points: 24,762, Level: 95 Points: 24,762, Level: 95
Level Up 42% Completed
Level up: 42% Level up: 42% Level up: 42%
Forum Activity 7%
Activity: 7% Activity: 7% Activity: 7%
FF Reputation: 49 dyn085 Great Standing Member
Buy-Sell-Trade Rating: (5)
Atmospheric pressure is actually a pretty big deal for n/a engines, especially considering the fact that suction doesn't actually exist in the way that most people think does.

The Ti-VCT responds very well to simple bolt-ons and reductions in intake restriction. I would not be surprised to see a gain with the larger TB, though I don't think it will be a decent cost-per-HP gain.
__________________
FocusFest 2013: Best of Show
Gateway FFW: Show Class Outstanding
September '13 ROTM
2014 FiST-
dyn085 is online now  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 08:59 PM   #87
goingtoscotland
Focus Addict
 
goingtoscotland's Avatar
 
Join Date: Dec 2013
Fan#: 132001
Location: Hull, IA
What I Drive: '14 Tuxedo Black HB, 05 Kawi ZX-10R

Posts: 775
Points 1,954, Level 26
Points: 1,954, Level: 26 Points: 1,954, Level: 26 Points: 1,954, Level: 26
Level Up 54% Completed
Level up: 54% Level up: 54% Level up: 54%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 6 goingtoscotland Good Standing Member
Buy-Sell-Trade Rating: (0)
If you were trying to get me to say that the MAP measures atmospheric pressure, I won't because it doesn't.
goingtoscotland is offline  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 09:11 PM   #88
suss6052
Focus Addict
 
suss6052's Avatar
 
Join Date: Feb 2012
Fan#: 95752
Location: ..., MI
What I Drive: 2013 Ford Focus ST2 Ingot Silver

Posts: 12,815
Points 9,903, Level 66
Points: 9,903, Level: 66 Points: 9,903, Level: 66 Points: 9,903, Level: 66
Level Up 64% Completed
Level up: 64% Level up: 64% Level up: 64%
Forum Activity 33%
Activity: 33% Activity: 33% Activity: 33%
FF Reputation: 24 suss6052 Great Standing Member
Buy-Sell-Trade Rating: (3)
Quote:
Originally Posted by goingtoscotland View Post
If you were trying to get me to say that the MAP measures atmospheric pressure, I won't because it doesn't.
The Focus N/A engine uses a mass air flow sensor, which uses a hot wire film to measure the air flow based on a voltage change across it.

However the Focus ST does directly read absolute pressures using a Manifold Absolute Pressure Sensor, well technically three as part of it's speed density system.
__________________
Moderator for: DURATEC Ti-VCT Performance, ST Performance, MK3 Focus
suss6052 is online now  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 09:18 PM   #89
GhostTribute
Focus Enthusiast
 
GhostTribute's Avatar
 
Join Date: Jan 2013
Fan#: 107929
Location: 506 East Coast, Canada
What I Drive: 2001 Mazda Tribute (2.0L Zetec)

Posts: 354
Points 318, Level 6
Points: 318, Level: 6 Points: 318, Level: 6 Points: 318, Level: 6
Level Up 36% Completed
Level up: 36% Level up: 36% Level up: 36%
Forum Activity 2%
Activity: 2% Activity: 2% Activity: 2%
FF Reputation: 1 GhostTribute Good Standing Member
Buy-Sell-Trade Rating: (0)
I have to say that as a former student of fluid dynamics and temperature related sciences this thread is making my head hurt. If you are unsure about what it is you are talking about...please don't.

Actually the map sensor will measure atmospheric pressure, if there is an absence of vacuum and or boost pressures inside the manifold...
GhostTribute is online now  
    Reply With Quote Quick reply to this message
Old 03-06-2014, 09:29 PM   #90
goingtoscotland
Focus Addict
 
goingtoscotland's Avatar
 
Join Date: Dec 2013
Fan#: 132001
Location: Hull, IA
What I Drive: '14 Tuxedo Black HB, 05 Kawi ZX-10R

Posts: 775
Points 1,954, Level 26
Points: 1,954, Level: 26 Points: 1,954, Level: 26 Points: 1,954, Level: 26
Level Up 54% Completed
Level up: 54% Level up: 54% Level up: 54%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 6 goingtoscotland Good Standing Member
Buy-Sell-Trade Rating: (0)
I read MAP for MAF, my mistake. Anyway, yes, a MAF measures the volume of air and accounts for density to meaure engine load as well

However, basically all you have done so far is use some half assed attempt with a static atmospheric pressure and in general been a douche. So how about you elaborate on your one liners and tell me why you think a larger throttle body will vastly improve performance, even if the stock TB is not a bottleneck. You could put a 150mm TB on it and it wouldn't make a difference, there's only so much air the manifold and valves in the engine can accommodate before you start artificially pressurizing the intake with forced induction.

.
Quote:
Originally Posted by dyn085 View Post
Atmospheric pressure is actually a pretty big deal for n/a engines, especially considering the fact that suction doesn't actually exist in the way that most people think does.

The Ti-VCT responds very well to simple bolt-ons and reductions in intake restriction. I would not be surprised to see a gain with the larger TB, though I don't think it will be a decent cost-per-HP gain.
It most certainly does. The denser the ambient air is, the more oxygen enters the engine for a given volume of air. However, it does not matter in the way he thinks it does. He's stating static atmospheric pressure acting on a surface in the vertical somehow directly relates to the flow of a fluid being forced through a restriction. That is not how it works, and regardless of pre-restriction pressure, pressure will always drop in the middle of that restriction. The larger the opening the less the pressure will drop, the smaller the opening, the more the pressure will drop, but only in the middle of that restriction.

And yes, it's not actually SUCKED IN, as higher pressure moves to lower pressure. In a carburetor for instance fuel isn't sucked out of the float bowl by the low pressure in the venturi, it is forced out because the float bowl is at a higher pressure than the venturi is.

Quote:
Originally Posted by GhostTribute View Post
I have to say that as a former student of fluid dynamics and temperature related sciences this thread is making my head hurt. If you are unsure about what it is you are talking about...please don't.

Actually the map sensor will measure atmospheric pressure, if there is an absence of vacuum and or boost pressures inside the manifold...
Indeed it would, but it's all in the application That is why the two sensors for Inlet Air Pressure and Ambient air pressure are usually the same part number on motorcycles. They have a vacuum hose nipple on the sensors, but only the IAP vacuum hose actually attached to anything which leads to the throttle bodies after the throttle valve. The atmospheric sensor vac hose just dangles there.
goingtoscotland 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

Forum Jump


All times are GMT -5. The time now is 12:11 AM.


Copyright 2002-2014 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 Audi S3, Ford Fusion and Acura TLX. You can find all Ford Focus and Focus ST related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. Challenger Hellcat - Charger Hellcat