| From | Message |
billybob
Dodge Dakota
8/13/2001
19:31:27
|
 Subject: RE: Ram Air
IP: Logged
Message:
your tb will alow 650 cfm to flow @ wot. your 318 @3000 rpm flows less then that, actaullt it would have to run at around 6000 to 6500 to come close to that flow rate. due to volumetric efficientcy or lack of it this is what happens. The TB flows more air then the engine itself can sooo if you have an intake directly in front of the vehicle that is 4X5 inches that opening is more then capable of flowing more air then the engine is. Now all this air is under pressure, it flows into the TB under pressure and acually flows more than it is ratted at as there is a lot higher pressure in the intake side of it then normal. Stick your hand out the window at 70 verses the amount of felt air pressure insde the cabin with the windows closed. Now this air is entering the manifold faster then the restricted flow magnun heads can suck it down. there for creating a pressure situation. If you had perfect volometric efficiantcy the 318 will flow all 650 cfm that the tb is allowing into the manifold. However that is not possible due to restricted heads manifolds valve timing and size etc. etc. etc. So what happens to all that extra air? well some of it will enter the engine as it is now under pressure instead of a vacuum, and some of it will show as manifold pressure. My bone stock except for the modifide self designed intake used to run 82 thew the traps now runs 89 and that is the only mod I have. no way to explain except the 3lb pressure in the manifold. I used to have a '79 turbo mustang that ran 5lb boost max (untill I modified that) but anyway the speed figures align pretty close to what that old terribly laging mustang turbo ran vs. a stock non turbo version of the same engine. Bernd you know a lot but not everything. The whole thing I guess is that I use a terribly large intake that tapers back all the way to the tb and actually increases the pressure a little all the way back. Anybody wanting to see it come on up to the Woodward Ave Cruise in Detriot this weekend, gonna make the trip all the way up from Alabama.
|
kota on 20s
Dodge Dakota
8/14/2001
17:21:42
| RE: Ram Air
IP: Logged
Message:
let me know if this makes any scence. there is no question that with the ram air setup that it builds boost at the throttle body, but after it goes through the TB, down the intake runners, and into the combustion chambor i dont think the pressure is still there. so it's just a cold air intake. albet better than others though.
just my thoughts, i could be completly wrong but let me know if im on the right track.
Eric
|
Hersbird
Dodge Dakota
8/14/2001
17:45:48
| RE: Ram Air
IP: Logged
Message:
Well I'm not an expert here but I have read about various "ram" air setups that have been tried over the years. When using pressure monitoring instruments along with different ram air setups it is very difficult to actually get a reading anywhere actually attached to the car. Like say a front facing hood scoop like the shaker. The scoop on a P-51 mustang was raised off the plane's body to achieve a true ram air. The scoop for the challenger T/A was modeled after this but it wasn't actually raised enough off the hood to accomplish the pressure increase. Every car does have a good high pressure zone and that is at the base of the window or the cowl. This is where every nascar motor takes the air from and that's not because of rules but because it functions better then taking it from the grill. If you connected a pipe from behind the grill where you are thinking, up to the cowl area and drove down the freeway, I bet the air would pull from the cowl and eject at the grill. What you feel when you stick your hand out the window is not air pressure on you hand but the wind resistance of you hand. Otherwise the following logic would work, you hand is about 15 sq-in and the force is 5 pounds at 50 MPH. If you had a scoop opening of that same 15 sq-in on each side that would be 10#! more then a supercharger makes! This setup would produce power because of a cold air effect, and that is best explained on intense performance's website. Their cold air setup as does K&N's are similar to what your talking about and never do they claim actually putting the motor under boost.
|
bernd
Gen III
8/15/2001
17:06:17
| RE: Ram Air
IP: Logged
Message:
Has anyone even looked into the actual aerodynamics of the system? If it's behind the grill and doesn't have a decent "scoop" (opening), it's just Cold Air Induction.
All this talk about boost, pressure, etc....but many have tried, many have been built (over the years), and many have just been Cold Air Induction kits (which do make more power...to a point).
Until there's some comparisons with the G-Forced Kit vs. Intense Performance vs. K&N vs. "RamAir Box"...i'll just sit back and watch the thread for a while.
1997 Dodge Dakota SLT - V6
Supercharged @ 10#
|
Dr.Q
Dodge Dakota
9/01/2001
23:06:45
| RE: Ram Air
IP: Logged
Message:
I was looking back through the threads on air intakes and I decided to take the curved funnel out of the front of the air box and the rubber flap off the front of the radiator. I went down to the hardware store to look at pvc piping, and a light bulb goes off A LEAF BLOWER! Amaze your freinds and neighbors! A little toungue and cheek here-but its diameter would fit into the air box perfectly, and if you only used it on runs-I don't know- mabe I'm sniffin too many exhaust fumes. But a 3" tube blowing air at over 100MPH kinda sounds like whats been described here as "ram air".
Seriously though, any results with the g-force system or the new 70mm TB and 4" z-tube out there? Hello? Anyone? Anyone? Beuller?
Waiting for the drugs to kick in-Your pal,
Dr.Q
|
Hersbird
Dodge Dakota
9/01/2001
23:29:14
| RE: Ram Air
IP: Logged
Message:
It doesn't make sense, the leaf blower is running on what, a 2 HP motor or less? I don't see how it could add much more power then it uses, even 5 times would still be only 10 HP. Also try putting your hand over the outlet of the leaf blower and I bet you can completely seal it off w/o to much effort, it's just not developing much pressure, pretty much the same reason these 'ram air' setups don't help outside of giving the engine a good cold stream of air.
|
Dr.Q
Dodge Dakota
9/02/2001
00:00:25
|  RE: Ram Air
IP: Logged
Message:
Actually I was kinda kidding. But I put my hand over the intake of the airbox. I was surprised how little air the was (at idle) flowing. But the 2 hp thing the air isn't being added as horsepwer the air is being added to increase the pressure to give more O2 to the engine.
But I am still interested in the increase in HP of the 70mm TB and 4" Z-tube setup Anyone? Anyone? Beuller?
|
TorontoDakota
Dodge Dakota
JOIN HERE
12/19/2002
03:45:27
|  RE: Ram Air
IP: Logged
Message:
really only very useful for hp gains in an older carbeurated engine or a SC'd engine
but the bottom line is that an engine is a pump and the more air flow the better
|
TorontoDakota
Dodge Dakota
JOIN HERE
12/19/2002
03:47:15
| RE: Ram Air
IP: Logged
Message:
really only very useful for hp gains in an older carbeurated engine or a SC'd engine
but the bottom line is that an engine is a pump and the more air flow the better
|
kota on 20s
GenIII
12/19/2002
03:50:20
| RE: Ram Air
IP: Logged
Message:
this thread is a year and 3 months old.
BUT what happend to G-force? i know they were trying to push a group buy, but i dont think anyone bought one (not a suprise why) did they go out of busniess, or just put the dodges on the back burner?
~Eric
superdupercharged, M-1, 1.7 RR's, 52mm TB, ceramic headers, 3" carsound cat, and gibson muffler
|
| | <<Oringinal Post <<Previous Page P 2 |
|
Post a reply to this message:
Username Registration: Optional
All visitors are allowed to post messages
|
