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Location:
melbourne
Registered:
November 2003
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4age bigport. taking advantage.
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Thu, 15 April 2004 10:08
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the first version 4age is the engine with the larger intake ports (bigport).
so my question is: is their anyway to take advnatage of these larger ports, and increase the pressure of fuel air mix going through this port? or trick the the computer into doing so for you?
doing something to the throttle bodie and air intake to let more air in, or something to the fuel rair or fuel pump to allow for more fuel and air to be mixed and crammed into the cylinder? maybe bigger injectors?
any ideas any1?
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Location:
Adelaide
Registered:
May 2002
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Re: 4age bigport. taking advantage.
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Thu, 15 April 2004 10:11
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"allow for more fuel and air to be mixed and crammed into the cylinder"
Turbo 
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Location:
Adelaide
Registered:
May 2002
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Re: 4age bigport. taking advantage.
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Thu, 15 April 2004 11:31
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I think you may be lacking some knowledge when it comes down to basic inlet system workings.
The ECU has nothing to do with the pressure of the fuel/air mix. The ECU will supply the 'correct' amount of fuel (pre-programmed amount) for the amount of air the load sensing device tells it the Engine os consuming.
Bigger injectors are pointless unless the current ones are unable to supply enough fuel (with reserve duty cycle) at your fuel systems operating pressure for the volume of air consumed by the engine.
N/A performance is pretty much reliant on the efficeiency of the inlet system. But as most things in life there are compromises. A max torque @ max revs inlet/camming systems is different to a max torque @ mid revs inlet/camming system.
Without a doubt the inlet systems will need revising, but you must think about your goals. Your goals will dictate such things as the following (but not limited to):
- Runner length
- Plenum size
- Inlet cam duration/timing
- Throttling
- Tuning
Excellent Inlet systems have been done many times before, just look at race cars. Some teams have even managed >100% inlet system efficeincy. That means thet through excellent timing and design a cylinder is able to be filled with more air than its swept capacity.
However use race teams only as a guide. What works for them does so under their exact circumstances and may prove useless to you...
Concentrate on just making a complete low restriction inlet tuned for a specific band with cams, timing and tuning to suit.
For us normal non-thermodynamic engineer types, there is the gift to torquey street cars of, you guessed it - forced induction!
Rex
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Location:
Melbourne
Registered:
March 2004
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Re: 4age bigport. taking advantage.
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Thu, 15 April 2004 12:04
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So was there any benefit to the head design in the 'bigport' engine then? Are they better to turbocharge? Yeah, yeah, i know, i should do a search.
Nice post btw, Rex.
"Flowers in one hand while the other hides a hammer" image + Adelaide location, eh? Not a Mark of Cain fan are ya? 
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Location:
melbourne
Registered:
November 2003
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Re: 4age bigport. taking advantage.
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Thu, 15 April 2004 14:06
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i guess what i was getting at with the ECU, and bigger injectors kinda thing was:
get injectors that attomize the fuel/air mixtures as much as possible, and use the computer to make these bigger injectors push MORE of the fuel/air mixture through the intake valves HARDER, FASTER adn with more pressure! thus meaning more air/fuel mixture is beeing pushed into teh cylinder.
is this makeing any sense at all, or im i completely retarded? im not an engineer or mechanic or anything, im just trying to think logically.
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Location:
Kita-Ku, Sapporo, Japan
Registered:
January 2003
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Re: 4age bigport. taking advantage.
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Fri, 16 April 2004 03:04
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no sorry, it doesn't make any sense at all..
have a look at what is involved in the intake system and you should realise that it does not work like this..
re-read Rex's post.
what you need to get more air/fuel into the cylinders is EITHER (AND ONLY)
MORE PORT VELOCITY
MORE PORT PRESSURE.
thats it.. the injectors just provide the fuel for the amount of air going in already.
Cya, Stewart
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Location:
Adelaide
Registered:
May 2002
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Banned by his request
Location:
moved to tamworth
Registered:
July 2002
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Re: 4age bigport. taking advantage.
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Fri, 16 April 2004 11:15
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simple answer! the big port is good for turbo and the small port is good for natural. small ports help velocity of air into the chamber. this has been covered about a zillion times in forums and on 4ag web sites. im more than happy to elaberate just ask but there is alot to changing flow rates of the 4ag heads as there isnt alot of meat around the ports etc.
mick
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Location:
Montrose, VIC
Registered:
May 2002
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Re: 4age bigport. taking advantage.
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Fri, 16 April 2004 13:49
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Sure, there's a great way of cramming more charge in at greater pressure, it's called super/turbocharging  Nitrous oxide would probably come closest to what you're talking about though...
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