Blue Oval Fanatics - Ford Forum

Go Back   Ford Forums & Technical Discussions > General Car Discussions > General Autombile News - Non Ford Related

Reply
 
Thread Tools Search this Thread
Old 05-05-2017, 11:14 PM   #1
I Bleed Ford Blue
Senior Pilot
 
I Bleed Ford Blue's Avatar
 
Join Date: Jun 2012
Fan#: 1121
Location: N.E., OH
What I Drive: 2017 Mustang GT convertible

Posts: 1,216
Rep Power: 37
I Bleed Ford Blue Excellent Standing MemberI Bleed Ford Blue Excellent Standing Member
Direct Injection explained

A question was asked on another forum about upgrading or adding direct injection or DI to a standard port injected coyote motor, and I realized that maybe a small tutorial was needed.

First off a little background, port injected uses injectors in the intake port to inject fuel into the air stream just before the intake valve. The air fuel mix is then sucked into the combustion chamber and compressed during the compression stroke. Because of this setup most naturally aspirated engines can only have a max of 11-11.5:1 compression ratio on pump gas (93 octane) as they are susceptible to detonation or pre-ignition. With the ever tightening federal C.A.F.E. standards the auto manufactures developed direct injection to try to meet the new standards.

What is direct injection? Well the manufactures borrowed technology from the diesel engine to develop DI, the fuel injector was moved from the intake port right into the cylinder head injecting fuel directly into the combustion chamber, hence the name direct injection. Along with the new high pressure injectors, new seals are required at the point where the injector goes into the head and at the fuel rail due to the extreme pressures and higher temps. Since the pressure inside the combustion chamber can reach 7-800 psi or higher, the fuel pump has to be able to create at least that much much pressure. If the fuel pressure is lower than the pressure outside the tip of the injector the combustion gases will backflow into the injector. Remember pressure flows from the higher pressure area to the lower pressure area. Because of this a new mechanical engine driven fuel pump is needed, as the standard electric powered impeller type pump is not capable of more than roughly about 100 psi.

Why direct injection? Well, DI allows for a higher static compression ratio. The 2.0 DI engine ford uses in the 2012 to current ford focus makes a 160 hp and has a 12:1 comp ratio and can run all day on 87 octane. How can this happen? Well DI injects the fuel right at the last split second before the spark plug ignites the air/fuel mix. Because of this, the chances of detonation is greatly reduced as the air/fuel mix does not have time to pre-ignite, and an added benefit is the slight cooling effect the fuel has during the injection process there-by reducing the chances of detonation even further. Why bother with higher compression ratios in the first place? Well higher compression allows for higher hp output out of a given displacement. 20 years ago extracting 160 hp out of a 2.0 liter 4 cylinder was unheard of from an american manufacturer, the norm back then was around 100-110 hp. And getting more power out a smaller engine equates to better fuel economy.

The drawback to DI is accelerated carbon buildup on the backside of the intake valve. A normal port injected engine has fuel sprayed onto the back of the valve washing off the oil/carbon residue and they rarely have any carbon buildup problems. Since DI engines no longer have fuel spraying the back of the valve, they get carbon buildup. How does the carbon get there in the first place? Simple answer, the PCV system. Some think that by using a high quality fuel you can reduce or eliminate the carbon buildup, personally I think that is hogwash. The carbon/oil gets there thru the PCV system in the first place, so that means the buildup is a byproduct of blowby, so when you have a higher load on a DI engine you get more buildup, it's that simple. To reduce or eliminate buildup you either have to drive like a granny to reduce the load on the engine or eliminate the PCV system all-together and run breathers like the old cars did back in the early sixties.

Ford found an elegant and an environmentally friendly solution to the buildup problem, they added back in port injection on DI engines. The DI system is kept as the primary fueling setup and port injection is added in small amounts just to wash the back of the intake valves. The first DI engine to get the new dual fuel setup is the second generation 3.5 ecoboost used in the 2017 f150. The fist gen had 365 hp with only DI and twin turbos. The second gen gets 375 hp with dual injection in the standard version. The high output version only available in the 2017 raptor gets 450 hp, and the the new ford GT gets a special 600 hp version, all out of a 3.5 L v-6. The 2018 5.0 coyote is slated to also get this new dual fuel setup and is rumored to get 455 hp in the mustang.
__________________
17 Grabber Blue Mustang GT PP convertible 401A
16 Ruby Red Edge SEL 201A
16 Blue Candy Focus Titanium 300A loaded
I Bleed Ford Blue is offline  
 
  Reply With Quote
Old 05-05-2017, 11:34 PM   #2
I Bleed Ford Blue
Senior Pilot
 
I Bleed Ford Blue's Avatar
 
Join Date: Jun 2012
Fan#: 1121
Location: N.E., OH
What I Drive: 2017 Mustang GT convertible

Posts: 1,216
Rep Power: 37
I Bleed Ford Blue Excellent Standing MemberI Bleed Ford Blue Excellent Standing Member
One more advantage of the dual fuel setup, the power potential is greatly increased. The original 3.5 ecoboost was rumored to max out around 600 hp, that was the fueling limit of the DI fuel pump. With the addition of port fuel back into the mix, you are now only limited by how much air you can get into the engine. You can max out the DI pump, and up the port injector size to get the rest of the needed fuel. On traditional port injection you were limited by injector size, if you went to big, you affected drive-ability, too small and you choked off hp. With dual fuel you can run smaller injectors and get great drive-ability but still get huge hp numbers. Think about it, the DI pump on a 3.5 ecoboost maxes out about 600 hp, add in the 300 hp of the standard non- eco 3.5 and you can potentially have a 900 hp v-6 that purrs like a kitten and drives like grandpas Lincoln, but can run like a scolded dog when needed.
__________________
17 Grabber Blue Mustang GT PP convertible 401A
16 Ruby Red Edge SEL 201A
16 Blue Candy Focus Titanium 300A loaded

Last edited by I Bleed Ford Blue; 05-06-2017 at 12:22 PM.
I Bleed Ford Blue is offline  
Reply With Quote
Old 05-08-2017, 01:53 PM   #3
white89gt
Administrator Shane
 
white89gt's Avatar
 
Join Date: Nov 2012
Fan#: 1293
Location: Salt Lake, UT
What I Drive: 1989 Mustang GT, 1997 F150

Posts: 4,930
Rep Power: 75
white89gt Outstanding Standing Memberwhite89gt Outstanding Standing Memberwhite89gt Outstanding Standing Memberwhite89gt Outstanding Standing Memberwhite89gt Outstanding Standing Memberwhite89gt Outstanding Standing Memberwhite89gt Outstanding Standing Member
Good info. Thanks my friend!
__________________
white89gt is offline  
Reply With Quote
Old 05-08-2017, 05:55 PM   #4
autolite
Senior Pilot
 
autolite's Avatar
 
Join Date: Jan 2013
Fan#: 1468
Location: Hinckley, OH
What I Drive: 1998 Black Mustang GT

Posts: 553
Rep Power: 40
autolite Excellent Standing Memberautolite Excellent Standing Member
What did Ford do to get the horse power up in the reg. V6 And the 5.0? 300 horse V6 will take my 4.6 to the cleaner.
__________________
98 Mustang GT
14 F150 XLT
10 Escape Limited,
06 Harley Ultra Classic
2008 Focus SE
autolite is offline  
Reply With Quote
Old 05-08-2017, 06:26 PM   #5
I Bleed Ford Blue
Senior Pilot
 
I Bleed Ford Blue's Avatar
 
Join Date: Jun 2012
Fan#: 1121
Location: N.E., OH
What I Drive: 2017 Mustang GT convertible

Posts: 1,216
Rep Power: 37
I Bleed Ford Blue Excellent Standing MemberI Bleed Ford Blue Excellent Standing Member
4 valves per cylinder, twin independent variable cam timing are the main reasons.
__________________
17 Grabber Blue Mustang GT PP convertible 401A
16 Ruby Red Edge SEL 201A
16 Blue Candy Focus Titanium 300A loaded
I Bleed Ford Blue is offline  
Reply With Quote
Old 05-30-2017, 07:53 PM   #6
biggie02
Cadet
 
Join Date: May 2017
Fan#: 4114
Location: hinesville, GA
What I Drive: 2006 Ford Escape

Posts: 10
Rep Power: 0
biggie02 Good Standing Member
Great info indeed. These dual setups make the engine more efficient with higher hp.
biggie02 is offline  
Reply With Quote
Old 06-04-2017, 01:28 AM   #7
Bob Ford
Cadet
 
Join Date: Jun 2017
Fan#: 4125
Location: Blegrade, Non-US
What I Drive: Ford Focus

Posts: 1
Rep Power: 0
Bob Ford Good Standing Member
I have one question about turbo engines and its maintenance. Which engine is cheaper to maintain: diesel or petrol? I know that some people prefer diesel for better torque and mileage while naturally aspirated petrol is cheaper for maintenance but fuel economy is worse. Adding turbocharger this flaw is eliminated but what about maintenance?
Bob Ford is offline  
Reply With Quote
Old 06-04-2017, 09:37 AM   #8
I Bleed Ford Blue
Senior Pilot
 
I Bleed Ford Blue's Avatar
 
Join Date: Jun 2012
Fan#: 1121
Location: N.E., OH
What I Drive: 2017 Mustang GT convertible

Posts: 1,216
Rep Power: 37
I Bleed Ford Blue Excellent Standing MemberI Bleed Ford Blue Excellent Standing Member
Here in the US diesel is a waste unless you do a lot of heavy towing. The mileage is about the same when your not towing, factor in the initial upfront cost of a diesel, the higher maintenance costs, the higher repair costs, and the higher cost of diesel fuel and you can see why diesel powered cars never really caught on over here.

Adding a turbo does increase maintenance and repair costs on a gas engine but they are still cheaper than a diesel.
__________________
17 Grabber Blue Mustang GT PP convertible 401A
16 Ruby Red Edge SEL 201A
16 Blue Candy Focus Titanium 300A loaded
I Bleed Ford Blue is offline  
Reply With Quote
Old 06-13-2017, 11:23 PM   #9
webbrowan
Cadet
 
Join Date: Jun 2016
Fan#: 3572
Location: Sydney, Non-US
What I Drive: o

Posts: 14
Rep Power: 0
webbrowan Good Standing Member
Thanks for sharing the info on the differences between diesel and petrol. I have been looking into that topic too because I am keen on saving costs so mileage is a winner to me. On the other hand, I have heard that diesel is not really heavy-duty as it is hyped to be. Thus, I am going to stick to petrol which I believe costs lesser in the long run in terms of maintenance and no major mileage difference from diesel.
webbrowan is offline  
Reply With Quote
Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not 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 -6. The time now is 02:50 AM.

Copyright 2015 BlueOvalFanatics.com. All Rights Reserved : Terms of Use : Privacy Policy : Advertise Information

Blue Oval Fanatics - Online Ford Community for the UK, North & South America, Europe, Asia, Australia, and Africa regions. We are the Internet's Newest Ford Forum. As our site continues to grow, we'll be offering a large collection of Ford related news, articles and club events information. We also offer a free Ford classifieds, gallery, social groups and events information. Our goal is to be the premier information outlet for Ford owners. If you own other makes have a look at Challenger Hellcat Forum, Charger Hellcat Forum, Cadillac ATS-V Forum, Cadillac CTS-V Forum, Lexus RC-F Forum, Lexus GS-F Forum, Mercedes GLA Forum, Mercedes GLE Forum and Volvo XC90 Forum.