Header question
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Originally Posted by joshdvirnak
Thats what I thought was MAF, the two into one. I should have been more clear, I meant two tubes between the filter box and the intake. I have two separate tubes, I am doing more research now, but from what I thought that was speed density, but it is a 95... hmm... interesting...
Edit: After some more research, I found that even though they started MAF in 94, most of the 351s didnt get it until 96. Chris, your truck wouldnt happen to be a california truck, would it? California models had MAF earlier due to their tighter standards.
Edit: After some more research, I found that even though they started MAF in 94, most of the 351s didnt get it until 96. Chris, your truck wouldnt happen to be a california truck, would it? California models had MAF earlier due to their tighter standards.
-Chris
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From: The Wilderness
Its not a big deal that it doesnt have it, there are a lot of people that do all of the basic intake, exhaust, ignition mods on speed densitys with no problems. when they start to have problems is when the engine size is increased.
As I understand, with speed density, it uses a programmed in setting for how much air the engine is using at a specific RPM. the computer then tells it how much fuel it needs. the O2 sensor tells the computer if it is rich or lean and the computer adjusts from there. it can adjust up to 25%, the problems start when the engine is bored or stroked. the O2 sensor says its running lean, but the computer cant compensate enough.
So, unless you are going to be doing a ton of high performance mods, a speed density truck should be just fine.
somebody correct me if I am wrong, or give me a pat on the back if I am right
As I understand, with speed density, it uses a programmed in setting for how much air the engine is using at a specific RPM. the computer then tells it how much fuel it needs. the O2 sensor tells the computer if it is rich or lean and the computer adjusts from there. it can adjust up to 25%, the problems start when the engine is bored or stroked. the O2 sensor says its running lean, but the computer cant compensate enough.
So, unless you are going to be doing a ton of high performance mods, a speed density truck should be just fine.
somebody correct me if I am wrong, or give me a pat on the back if I am right
Postmaster
Joined: Mar 2006
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From: The Wilderness
Check out this link, http://fordfuelinjection.com/?p=4
It defines the different Fuel injection types, and gives benefits and downfalls of each kind. such as MAF will sense changes in engine, but SD reacts to throttle change sooner. It shows that Speed Density is not as evil as everyone thinks it is, and MAF isnt as perfect as everyone thinks it is. It even says SD can handle more power than MAF... Interesting... its a give and take thing. very good reading
It defines the different Fuel injection types, and gives benefits and downfalls of each kind. such as MAF will sense changes in engine, but SD reacts to throttle change sooner. It shows that Speed Density is not as evil as everyone thinks it is, and MAF isnt as perfect as everyone thinks it is. It even says SD can handle more power than MAF... Interesting... its a give and take thing. very good reading
Last edited by joshdvirnak; May 17, 2007 at 01:03 AM.
Postmaster
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From: The Wilderness
Well, I feel bad about hijacking this thread, so...
back on topic, Entity, if you are planning on doing the exhaust your self, I know that they make a header reducer that bolts right up to a set of long tube headers that already has a O2 sensor bung on it, and then you just start putting the pipes on after that.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=WLK-88313&N=700+400358+4294865471+115&autoview=sku
I have all of my pieces picked out for when I purchase my headers and exhaust, and I am gonna buy these, i know I could have a bung put on, but I am doing the exhaust myself and its easy this way
back on topic, Entity, if you are planning on doing the exhaust your self, I know that they make a header reducer that bolts right up to a set of long tube headers that already has a O2 sensor bung on it, and then you just start putting the pipes on after that.
http://store.summitracing.com/partdetail.asp?autofilter=1&part=WLK-88313&N=700+400358+4294865471+115&autoview=sku
I have all of my pieces picked out for when I purchase my headers and exhaust, and I am gonna buy these, i know I could have a bung put on, but I am doing the exhaust myself and its easy this way
Posting Guru
Joined: Jan 2006
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From: The dark carnival
Originally Posted by joshdvirnak
the problems start when the engine is bored or stroked. the O2 sensor says its running lean, but the computer cant compensate enough.
So, unless you are going to be doing a ton of high performance mods, a speed density truck should be just fine.
somebody correct me if I am wrong, or give me a pat on the back if I am right
So, unless you are going to be doing a ton of high performance mods, a speed density truck should be just fine.
somebody correct me if I am wrong, or give me a pat on the back if I am right
Power range - Idle to 4400 rpm
Intake lift - .448
Exhaust lift - .478
Intake duration adv. - 280
Exhaust duration adv. - 290
Intake duration @ .50 - 204
Exhaust duration @ .50 - 214
Intake lobe centerline - 107
Exhaust lobe centerline - 117
This cam is nothing radical.
It's my experiance that it don't take much to get out of the limits of speed density. Anything that alters the volumetric effieciency of the motor can throw the SD system out of wack.
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From: The Wilderness
Not wanting to get back off topic, but to answer your question, Ryan at fordfuelinjection aparently knows a lot about these systems and says that what really messes up speed density is increased displacement or to much air, which creates a lean state that throws it off, I will be the first to say that I dont know much about cams at all. what would that cam do to the air/fuel ratio? check out that link I posted, it answered a ton of questions I had about MAF and speed density.
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Eco you forgot about the Side Channeling Thunder-Flarable Flange Compensation Rating... What were stats for that? 
Love bein a smart ***. This is just my way of saying you've gone WAY over my head 
-Chris
Love bein a smart ***. This is just my way of saying you've gone WAY over my head -Chris
Posting Guru
Joined: Jan 2006
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From: The dark carnival
The guy's at FFI do know alot, I have talked to them a few times. Thats where I got all my EGR eliminator parts.
I don't fully understand what exactly that cam does that throws off the SD system, but it has someting to do with the lobe centerline being too low. I have been told that lobe centerline needs to be at ~114. That is the cam in my 302 and it would not run @ less than 1500 rpm without extra fuel... be it an increase in fuel pressure, propane added to the air intake or what ever. It leaned the motor out big time.
I don't fully understand what exactly that cam does that throws off the SD system, but it has someting to do with the lobe centerline being too low. I have been told that lobe centerline needs to be at ~114. That is the cam in my 302 and it would not run @ less than 1500 rpm without extra fuel... be it an increase in fuel pressure, propane added to the air intake or what ever. It leaned the motor out big time.
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Posting Guru
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From: The dark carnival
Originally Posted by Skandocious
Eco I assume thats a typo in your signature. You're not driving a van are you? E-150? LOL
-Chris
-Chris
Junior User
Joined: Mar 2007
Posts: 92
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From: Glasgow,Ky.
OK I stand corrected I was going by what I was told on the OBDs. When I got mine it had a short pipe in the front of the system which had the o2 sensor in it. It was in front of the converters. I don't know where it came from but it seems to me you know whats is supposed to be there and mine is not original. Thanks for the comments.
Postmaster
Joined: Mar 2006
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From: The Wilderness
Second Chance, could you describe this "short pipe" for me, I am not clear on what you are describing. because on my truck, there is a "short pipe" the connects both of the pipes right before they enter the first cat. converter.
how long is the pipe you are talking about?
how long is the pipe you are talking about?
Postmaster
Joined: Oct 2006
Posts: 4,816
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From: Davis & Newcastle, CA
Originally Posted by second chance
OK I stand corrected I was going by what I was told on the OBDs. When I got mine it had a short pipe in the front of the system which had the o2 sensor in it. It was in front of the converters. I don't know where it came from but it seems to me you know whats is supposed to be there and mine is not original. Thanks for the comments.
And eco, I just assumed it was a typo because 1) you're on the truck forum and 2) because you have all those engine mods! I've never heard or seen of someone tricking up a Ford E Van. Ultimate sleeper I guess. Does it look cool?
-Chris
Junior User
Joined: Mar 2007
Posts: 92
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From: Glasgow,Ky.
Maybe 4 inches, it goes from one manifold down pipe to the other with the o2 sensor in the middle. It is located just after the left manifold pipe comes over to the right side. It appears to be factory, if not I sure would like to learn a few tricks from the welder that built it.