Redesigned!! Steed competition manifold vs Standard Steed

lenahan05 said:
just because air is under pressure doesnt mean its going to act any different...just means its going to act faster. if it scavenges at atmospheric pressure why wont it at 50 times that? if you could, explain how/why you think it will act different?
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yes, it will act differently....
....and 50x atmospheric is 735psig, so it would probably burst at that pressure [/sarcasm]


my explaination...I'm no expert, so if I'm wrong, someone call me out...at atmospheric pressure on the outlet of a header, there is x amount of scavenging available; as the outlet pressure is increased (the case of a turbo/higher restriction), scavenging decreases because the ability for a low-pressure area to form behind each exhaust pulse is diminished. It is conceivable that at certain operating conditions at very low pressure there may be some scavenging present in this manifold, but as drive pressure (and boost) builds, it goes away.

And as I have said before, I like the manifold.
 
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You might have a small point. It may change under high pressure. Although big company's ( cummins) teach you that there is scavenging. They have whole presentations that are devoted to how the manifold works. I am with steed on this
 
Hurley said:
yes, it will act differently....
....and 50x atmospheric is 735psig, so it would probably burst at that pressure [/sarcasm]


my explaination...I'm no expert, so if I'm wrong, someone call me out...at atmospheric pressure on the outlet of a header, there is x amount of scavenging available; as the outlet pressure is increased (the case of a turbo/higher restriction), scavenging decreases because the ability for a low-pressure area to form behind each exhaust pulse is diminished. It is conceivable that at certain operating conditions at very low pressure there may be some scavenging present in this manifold, but as drive pressure (and boost) builds, it goes away.

And as I have said before, I like the manifold.
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You have to look at the big picture. Scavenging is irrelevant to drive pressure when its equal across the board. Basically since drive pressure is equal on all ports then the cyl fires it creates a scavenging effect on the neighboring cylinders due to velocity. It is not creating a vacuum in the other cylinders @ our running drive pressures but I see it lowering the drive pressure in those port runners.
 
It looks nice
I want this manifold T4 and wastegate
Maybe someone can help me to send this Estonia?
 
Hurley said:
yes, it will act differently....
....and 50x atmospheric is 735psig, so it would probably burst at that pressure [/sarcasm]


my explaination...I'm no expert, so if I'm wrong, someone call me out...at atmospheric pressure on the outlet of a header, there is x amount of scavenging available; as the outlet pressure is increased (the case of a turbo/higher restriction), scavenging decreases because the ability for a low-pressure area to form behind each exhaust pulse is diminished. It is conceivable that at certain operating conditions at very low pressure there may be some scavenging present in this manifold, but as drive pressure (and boost) builds, it goes away.

And as I have said before, I like the manifold.
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When the exhaust valve cracks at blowdown, the spent gases and heat DO NOT slow down as they exit the cylinder. they keep a constant speed throughout at atmospheric pressure and gain speed as boost/cylinder pressure raises. it's a proven fact. if they did, scavenging would never occur. and your statement of (drive pressure and boost) in the same sentence is like comparing budweiser to keystone.....were talking about scavenging. not camshaft overlap. just trying to understand where all this bad internet info comes from. i've come to believe that the internet is bad news for learning in most cases. learn from the guys that are getting it done in competition. the manifold looks good steed. ill be putting in a few more orders like i have in the past. keep up the good work and turning out nice products for guys like me to buy/sell/compete with.
 
lenahan05 said:
When the exhaust valve cracks at blowdown, the spent gases and heat DO NOT slow down as they exit the cylinder. they keep a constant speed throughout at atmospheric pressure and gain speed as boost/cylinder pressure raises. it's a proven fact. if they did, scavenging would never occur. and your statement of (drive pressure and boost) in the same sentence is like comparing budweiser to keystone.....were talking about scavenging. not camshaft overlap. just trying to understand where all this bad internet info comes from. i've come to believe that the internet is bad news for learning in most cases. learn from the guys that are getting it done in competition. the manifold looks good steed. ill be putting in a few more orders like i have in the past. keep up the good work and turning out nice products for guys like me to buy/sell/compete with.
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What in the Phuck are you talking about?
 
Joesixpack said:
What in the Phuck are you talking about?
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exhaust gas speed at atmospheric pressure, it doesnt slow down. when you add boost-you add cylinder pressure, inturn-adding drive and exhaust port air velocity. read it. then go back and read it again....you'll get it sooner or later. MAYBE...... that word ''Phuck" doesnt make you sound that cool....JUST SAYIN.:bang
 
lenahan05 said:
exhaust gas speed at atmospheric pressure, it doesnt slow down. when you add boost-you add cylinder pressure, inturn-adding drive and exhaust port air velocity. read it. then go back and read it again....you'll get it sooner or later. MAYBE...... that word ''Phuck" doesnt make you sound that cool....JUST SAYIN.:bang
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You dip chit, the exhaust sees the turbine nozzle before atmosphere and hence why you see many of us talking about back pressure.

Your whole paragraph is garbage the same stuff your *****ing about. Your "Phucking" up my Internet.
 
I think clarification needs to be obtained on the actual mechanics of exhaust gas scavenging, and then we can compare that to the mechanics of pulse tuning/cadence and energy transfer to the turbine wheel of a turbo.
 
Hurley said:
I think clarification needs to be obtained on the actual mechanics of exhaust gas scavenging, and then we can compare that to the mechanics of pulse tuning/cadence and energy transfer to the turbine wheel of a turbo.
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No need for that...

He has a leaf blower and cardboard:hehe:
 
Joesixpack said:
You dip chit, the exhaust sees the turbine nozzle before atmosphere and hence why you see many of us talking about back pressure. QUOTE]

REALLY? guess i forgot about that. its hard talking to and pleasing the internet diesel gods.:lolly:
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I think the effective use of Bernoulli's principle has less to do with system pressure and more with flow. It may not produce an area of vacuum, but could definitely produce an area of lower pressure.

I could also see it becoming a completely moot point when you have excessive drive pressures.

Oh, and the "tested by leaf blower and cardboard" has to be the worst bit of marketing ever produced. LOL
 
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