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View Poll Results: Cold air vs Ram air
Cold Air 17 60.71%
Ram Air 11 39.29%
Voters: 28. You may not vote on this poll

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  #121 (permalink)  
Old 05-14-2009, 12:47 PM
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Quote:
Originally Posted by ap72
I actaully(sic) am an engineer
Is Amtrak hiring? lol

Of course I jest. You're a good dude.

Just so I'm on the same page, is my assumption above (post #119) in re the question we're discussing, valid?

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  #122 (permalink)  
Old 05-14-2009, 12:51 PM
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As far as track vs street- the engine knows no difference so the argument that it will work on the track but not on the way to the track is really BS. I'm glad you're seeing it work on the track though- it means you're on your way to enlightenment
It does make a HUGE difference, street driven vs track driven. The engine doesn't know squat, but if it's intended purpose was for drag race only, the builds are night and day different. One may never see 4000RPM or speeds at which Ram Air would have any use at all, whereas a drag race only engine may operate at or near 8500RPM, at speeds 3-4 times (or more) the street driven. If you had no net increase below 100mph, it would be senseless to utilize such thing for a road car if no increase until 100mph+. The race vehicle may see some gains, but given the operating time and total consumption of A/F along with the window of time (read short and figure all of your gains within these mere seconds) where there was some gain, it too would seem negligible - not to say it couldn't have a positive effect for a specific application. One size does not fit all. Thats not BS. As for enlightenment, that happened shortly after birth, and has been ongoing since the initial illumination.

Say for a race app, one would be better served finding power within a given combo, and then when squeezing every last bit possible trying something like Ram Air. If a gain is realized, good. If not, no harm no foul. In other words, don't assume Ram Air is going to work for Joe because it did for Chuck. Here, build an engine, put it on a dyno and determine the results. Then take your Ram Air set up and install as if on the vehicle. Get some 150mph blower(s) and direct them at your inlets and dyno again. Of course, you would have the full affect of Ram Air before actual use speed (vs engine operation range) so data would be skewed, but I doubt the gain would be worth the effort. JMO
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  #123 (permalink)  
Old 05-14-2009, 12:56 PM
How fast is fast enough?
 
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Cobalt, I like you, you're about as stubborn as a mule... or myself.

And yes, if you increase drag to the point of neglecting the gains from RA then its pretty much a mute point. The RA effect will still be working but at a net loss to the driver. More power will be produced but more will be consumed as well.
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  #124 (permalink)  
Old 05-14-2009, 12:58 PM
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Quote:
Originally Posted by ap72
Cobalt, I like you, you're about as stubborn as a mule... or myself.

And yes, if you increase drag to the point of neglecting the gains from RA then its pretty much a mute point. The RA effect will still be working but at a net loss to the driver. More power will be produced but more will be consumed as well.
Thanks for the clarification.

Hee-Haw! lol
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  #125 (permalink)  
Old 05-14-2009, 01:04 PM
How fast is fast enough?
 
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Quote:
Originally Posted by Deez
It does make a HUGE difference, street driven vs track driven. The engine doesn't know squat, but if it's intended purpose was for drag race only, the builds are night and day different. One may never see 4000RPM or speeds at which Ram Air would have any use at all, whereas a drag race only engine may operate at or near 8500RPM, at speeds 3-4 times (or more) the street driven. If you had no net increase below 100mph, it would be senseless to utilize such thing for a road car if no increase until 100mph+. The race vehicle may see some gains, but given the operating time and total consumption of A/F along with the window of time (read short and figure all of your gains within these mere seconds) where there was some gain, it too would seem negligible - not to say it couldn't have a positive effect for a specific application. One size does not fit all. Thats not BS. As for enlightenment, that happened shortly after birth, and has been ongoing since the initial illumination.

Say for a race app, one would be better served finding power within a given combo, and then when squeezing every last bit possible trying something like Ram Air. If a gain is realized, good. If not, no harm no foul. In other words, don't assume Ram Air is going to work for Joe because it did for Chuck. Here, build an engine, put it on a dyno and determine the results. Then take your Ram Air set up and install as if on the vehicle. Get some 150mph blower(s) and direct them at your inlets and dyno again. Of course, you would have the full affect of Ram Air before actual use speed (vs engine operation range) so data would be skewed, but I doubt the gain would be worth the effort. JMO

Actually the effect would be greater if the engine speed is less relative to the car's velocity. And if it works at 100 MPH then why not at 99? or 90? say 45? what about 15? Also, if it did work for Joe and Larry but not for Chuck and not much for Bob then why was it different? And the blower idea was what we were trying to get at with the wind tunnel appraoch. Its harder than you think to find a place that can do those kind of tests.
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  #126 (permalink)  
Old 05-14-2009, 06:19 PM
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Quote:
Originally Posted by 83SILVRADO
im sorry... i cant do this anymore. every thread that you post on turns into this... everyone against you and you still not understanding. im pretty much done with this post... its just pissin me off anyway. i do not want this poll to be deleted. not until its way dead. this post has a ton of information on it. so i say we keep it as long as we can
Who would've thought a question about cold and ram air could generate so much hot air!



If you can't fix it with a hammer, the problem must be electrical.
Bogie
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  #127 (permalink)  
Old 05-16-2009, 05:38 AM
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yup...............
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  #128 (permalink)  
Old 05-16-2009, 09:45 AM
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I want to go all the way back to something that I feel was missed...

Quote:
Originally Posted by ap72
Here is the easiest way of sowing the effects of ram air do not increase drag. It is admitidly primitive but also easily understood.

take a large box and swing in through the air.
Now cut a whole in the face of the box and swing it through the air.
No extra drag has been created but the pressure at the face of the box has passed through it, in fact reducing drag.
Now cover it back up, this is what the car would experience in motion with the engine off (no air passing through the hole).
With the car at WOT then the pressure felt would be much less (as flow through the hole in the box goes up then the pressure exerted on its face goes down).

Your analogy is exceptionally flawed. By cutting a hole in the box, you have allowed free passage of air through the hole which reduces its drag. The air pressure going through that hole is LESS than atmospheric as per Bernouli's Principle. If you want a better example, cut a hole in the box and tape a plastic bag in the hole. Then swing it around. The bag will "inflate" and cause more drag than before.

You fail to incorporate the fact that in order for RA to produce pressure, it must block flow. Getting pressure from flow means that you must convert kinetic energy into potential, which means harnessing the inertia of flow. If you borrow energy from flow, the flow decreases. It has to. That's first law of physics stuff. So your box analogy is terrible. It neglects 90% of the functions happening in a RA setup. First of all, on the other end of that RA ducting is a throttle plate. Secondly, if you think it reduces drag, then the engine would have to be sucking faster than the ducting received air. If its creating pressure, then its increasing drag. It must. There is no way around the first law of physics. Jets do it. They suck air in a lot faster than they encounter it, but those huge round turbine housings still create a very large amount of drag.

Imagine yourself in a plane. Cut a hole in the nosecone. The pressure in the cabin might rise slightly. cut a hole in the fuselage or tail, chances are the pressure will decrease in the cabin. It doesn't matter. If you are using flow to generate a pressure differential, it WILL CREATE ADDITIONAL DRAG. It physically has to. It can't not.

Quote:
I'm realy trying to boil it down to the basics here in hopes that people will begin to understand it.
ap... I want to say this man to man and without any emotion involved. The fact that you incorrectly spelled "hole," your odd contextual misuse of the gerand "sowing," and your lack of ability to grasp very simple concepts about fluid dynamics means you are not a child-engineer prodigy. You are an anonymous internet soapboxer who [by your own admission] is too stubborn to change. Most of us here don't have respect for your behavior in this thread, but if you were able to approach this like a man and say, "let's discuss and maybe I'll learn something," I would respect you immensely. ...Instead of condescending to us by saying you're "boiling it down to basics so we can understand," which is just about enough to make ME boil.

If you stepped back and allowed yourself to learn instead of sticking to your guns on this, maybe you could have been a prodigy engineer.

Last edited by curtis73; 05-16-2009 at 10:07 AM.
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  #129 (permalink)  
Old 05-16-2009, 11:16 AM
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Quote:
Originally Posted by curtis73
I want to go all the way back to something that I feel was missed...




Your analogy is exceptionally flawed. By cutting a hole in the box, you have allowed free passage of air through the hole which reduces its drag. The air pressure going through that hole is LESS than atmospheric as per Bernouli's Principle. If you want a better example, cut a hole in the box and tape a plastic bag in the hole. Then swing it around. The bag will "inflate" and cause more drag than before.

You fail to incorporate the fact that in order for RA to produce pressure, it must block flow. Getting pressure from flow means that you must convert kinetic energy into potential, which means harnessing the inertia of flow. If you borrow energy from flow, the flow decreases. It has to. That's first law of physics stuff. So your box analogy is terrible. It neglects 90% of the functions happening in a RA setup. First of all, on the other end of that RA ducting is a throttle plate. Secondly, if you think it reduces drag, then the engine would have to be sucking faster than the ducting received air. If its creating pressure, then its increasing drag. It must. There is no way around the first law of physics. Jets do it. They suck air in a lot faster than they encounter it, but those huge round turbine housings still create a very large amount of drag.

Imagine yourself in a plane. Cut a hole in the nosecone. The pressure in the cabin might rise slightly. cut a hole in the fuselage or tail, chances are the pressure will decrease in the cabin. It doesn't matter. If you are using flow to generate a pressure differential, it WILL CREATE ADDITIONAL DRAG. It physically has to. It can't not.



ap... I want to say this man to man and without any emotion involved. The fact that you incorrectly spelled "hole," your odd contextual misuse of the gerand "sowing," and your lack of ability to grasp very simple concepts about fluid dynamics means you are not a child-engineer prodigy. You are an anonymous internet soapboxer who [by your own admission] is too stubborn to change. Most of us here don't have respect for your behavior in this thread, but if you were able to approach this like a man and say, "let's discuss and maybe I'll learn something," I would respect you immensely. ...Instead of condescending to us by saying you're "boiling it down to basics so we can understand," which is just about enough to make ME boil.

If you stepped back and allowed yourself to learn instead of sticking to your guns on this, maybe you could have been a prodigy engineer.

I don't know why this is so hard for you to understand, maybe it has to do more with perspective than knowledge, or maybe more about understanding than knowledge. The first law of physics crap is what people say when they don't understand what they are talking about. Drag does not need to increase to create RA, I don't know why you keep holding onto this idea that it does. In fact assuming you don't change the lines of the viehicle it actaully has to DECREASE according to the first law of physics. But the drag is not the issue.

And an engine does not expand when you force air into it like a bag- if it did we'd all be in big trouble.
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  #130 (permalink)  
Old 05-16-2009, 04:25 PM
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I'm just speechless.

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  #131 (permalink)  
Old 05-16-2009, 05:15 PM
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Further reading for parties who feel that the laws of physics are "crap" ,can be found here

and here...

Later, mikey
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  #132 (permalink)  
Old 05-16-2009, 11:22 PM
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Quote:
Originally Posted by ap72
The first law of physics crap
LOL!

Quote:
Drag does not need to increase to create RA, I don't know why you keep holding onto this idea that it does.
But, you just said:

"The RA effect will still be working but at a net loss to the driver. More power will be produced but more will be consumed as well."

You've failed to take anything in to account that doesn't somehow allow you to hold on to your false beliefs.

Kind of sad, in a pitiful sort of way...
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  #133 (permalink)  
Old 05-17-2009, 01:22 AM
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Quote:
Originally Posted by cobalt327
Kind of sad, in a pitiful sort of way...
I was going to say kind of pathetic in a water-fueled-car sort of way.
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  #134 (permalink)  
Old 05-17-2009, 12:11 PM
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One thing that folks have not addressed at all is how much effect the additional power you get from ram air will effect exhaust gas..

The exhaust is really thrust, (otherwise how would jets fly?..duh), so any added power you get from the motor will also increase thrust at the back of the car...

Now please don't try to confuse the issue by saying that the rear of any object moving through a gas with mass,(or mixture of gases, such as out atmosphere is), has a low pressure area behind it, and the exhaust has nothing to push against...

That would totally mess up my theory. I'll be working on my empirical testing methods today, using my Shovelhead as a test vehicle.. (it would be a better test if the speedometer needle was still attached to the little shaft, but it rattled off so I'll just try to count phone poles as they go by to get some reliable results.

Later, mikey
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  #135 (permalink)  
Old 05-17-2009, 12:52 PM
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Quote:
Originally Posted by powerrodsmike
One thing that folks have not addressed at all is how much effect the additional power you get from ram air will effect exhaust gas..

The exhaust is really thrust, (otherwise how would jets fly?..duh), so any added power you get from the motor will also increase thrust at the back of the car...

Now please don't try to confuse the issue by saying that the rear of any object moving through a gas with mass,(or mixture of gases, such as out atmosphere is), has a low pressure area behind it, and the exhaust has nothing to push against...

That would totally mess up my theory. I'll be working on my empirical testing methods today, using my Shovelhead as a test vehicle.. (it would be a better test if the speedometer needle was still attached to the little shaft, but it rattled off so I'll just try to count phone poles as they go by to get some reliable results.

Later, mikey
Now we're getting to the real nuts and bolts of scientific theory! Just don't wear a helmet as that would tilt the results (by adding more drag). Document the exact octane also as we don't want you running any jet fuel in the shovelhead (might blow a head gasket). If it leaks a little oil while you're moving does that cause drag? After all we are looking for a noticeable difference and a little dripping oil WILL be noticeable! LOL
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