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					29-10-2008 10:57 AM
				
			
			
				
					#2053
				
				
				
			
		
	 
		
		
			
				
				
						
							
							
						
						
				
					
						
							if anyone is interested the FN also comes with one
						 
	
		
			
				
					29-10-2008 11:38 AM
				
			
			
				
					#2054
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							I'd like to qualify what I said. I didn't say that it would have no effect. I said it would be negligible.
 You've posted a range of articles that give us a heap of different information. I'm not too sure what kind of a point you want to make here. Are you trying to convince me that the airflow across a Porches separates and recirculates in various places. Or are you trying to tell me that improving your vehicles aerodynamics improves fuel consumption numbers. Perhaps you're trying to tell me that your undercarriage cover acts just like the undertray and diffuser assembly of a Ferrari Ezno and gives you downforce! And these very fancy-looking CFD images you've given really don't support your point much at all...unless your point was that the Honda Civic is completely different from a Mercedes E-Class.
 Altogether I think that you were trying to say that improving the aerodynamic characteristics of the car improves performance. That's correct and I'd hardly disagree else I wouldn't end up with a job (I'm studying Aerospace Engineering).
 
 My original point was that I didn't believe the improvements made to your car would offer large performance increases. The best piece of information you offered was the two numbers at the bottom. The Cds for the two cars.
 Overall the Civic Hybrid experience a grand total of just shy of 6kgs of drag less than the stand Civic at 100 kph.
 But then your car isn't the standard Hybrid either. You've got a wing on the rear and some pretty schmick wheels. Those aren't going to have the same characteristics as the Hybrid. You therefore can't claim the whole .04 decrease in Cd.
 
 My main point is that unless you cruise everywhere very fast, the fuel savings you'll see are negligible. But even if you weren't after fuel savings, but increased downforce. I'd wager that the increases would be tiny. The under carriage tray wouldn't promote pressure gradients in order to produce downforce.
 
				
				
				
					
						Last edited by Havocwreaker; 29-10-2008 at 11:41 AM.
					
					
				 
	
		
			
				
					29-10-2008 02:04 PM
				
			
			
				
					#2055
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							in the end its dmx car, so he can do whatever he wants  
 ppl still put stikcers, type R emblems, decals, etc on their car without any effect right?
 
				
                                       
                                 
				
		        		 
Bye2 Honda... Hello Mazda family  
 
	
		
			
				
					29-10-2008 02:21 PM
				
			
			
				
					#2056
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							I thought stickers made ur car go faster...
						 
	
		
			
				
					29-10-2008 02:26 PM
				
			
			
				
					#2057
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							no actually it slows down the car, its add extra weight to the car   
				
                                       
                                 
				
		        		 
Bye2 Honda... Hello Mazda family  
 
	
		
			
				
					29-10-2008 02:48 PM
				
			
			
				
					#2058
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							
	i removed the civic and sport badge and my car sprint from 0 to 100 in 1 sec!
		
			
			
				
					  Originally Posted by denot   no actually it slows down the car, its add extra weight to the car     
	
		
			
				
					29-10-2008 07:34 PM
				
			
			
				
					#2059
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							
	if you can get the summary/point of those articles, all give you the same conclusion : undercarriage/undertray/belly pan cover will give you more aero to reduce drag.
		
			
			
				
					  Originally Posted by Havocwreaker   You've posted a range of articles that give us a heap of different information. I'm not too sure what kind of a point you want to make here. 
 .
 by reducing the drag (with better aero), it might help your perfomance (regardless what is the car or small/large impact), but by the science, it will
 
  
 
 
	ur previous post :
		
			
			
				
					  Originally Posted by Havocwreaker    Or are you trying to tell me that improving your vehicles aerodynamics improves fuel consumption numbers. .
 
 
 
	
		
			
			
				
					  Originally Posted by Havocwreaker   If it seriously reduces noise, then you really can't put a definitive value on that. DMX might really appreciate a quiet drive. But I don't think the fuel consumption figures will tumble. 
	and sometimes i quite don't really understand what is your original point.
		
			
			
				
					  Originally Posted by Havocwreaker I really don't believe it's a significant increase in drag reduction, that's all. Sure there are a heap of odd shapes and cavities underneath the car but smoothing all of that out won't really lower your coefficient of drag.Even if you get air trapped in the nooks and crannies underneath the stagnant pockets of air they produce would be negligable compared to what you'd get off the back of the car.
 let we start with your 1st point : the Fuel consp (FC), the scientific result, clearly give us some correlation, regardless what is your car, regardless small/big impact
 
  if you can read the chart : cd 0.25 : to reach 100kmh need 10kw power
 cd 0.35 : need 12-13 kw power. means the lower cd, lower power needed, and as result less FC.
 but once again : as my first post said :
 
 
	and for the ur 2nd point :
		
			
			
				
					  Originally Posted by dmx   this is a simple yet useful mod if you understand the physics about air drag.. but it is also a mod which you can't really feel anything but its benefit does exist in daily driving...  
 
	if you read all the articles before, at the end you will get the answer (undercarriage/undertray/belly pan cover will reduce cd)
		
			
			
				
					  Originally Posted by Havocwreaker I really don't believe it's a significant increase in drag reduction, that's all. Sure there are a heap of odd shapes and cavities underneath the car but smoothing all of that out won't really lower your coefficient of drag.Even if you get air trapped in the nooks and crannies underneath the stagnant pockets of air they produce would be negligable compared to what you'd get off the back of the car.
 http://www.ozhonda.com/forum/showpos...postcount=2047
 
 
 
	
		
			
			
				
					  Originally Posted by Havocwreaker Perhaps you're trying to tell me that your undercarriage cover acts just like the undertray and diffuser assembly of a Ferrari Ezno and gives you downforce! And these very fancy-looking CFD images you've given really don't support your point much at all...unless your point was that the Honda Civic is completely different from a Mercedes E-Class.Altogether I think that you were trying to say that improving the aerodynamic characteristics of the car improves performance.
 
	and i NEVER say improvement by undercarraige cover will give you large perf. increases, check my previous post. the only way to get large perf. : Supercharged or Turbo. what ever you "playing", at the end, still Turbo/suprch.
		
			
			
				
					  Originally Posted by Havocwreaker   My original point was that I didn't believe the improvements made to your car would offer large performance increases.  
 
	
		
			
			
				
					  Originally Posted by dmx   1. the covers made the bottom more smooth hence reducing some moving air trap at the under carriage2. the car is alittle more quite while driving fast
 3. Fuel consp. improve
 and the main purpose is to smoothen the airflow underneath, to reduce drag.
 
	Did i ever claim with this undercarriage cover will reduce civic FD cd by 0.4 ???
		
			
			
				
					  Originally Posted by Havocwreaker   The best piece of information you offered was the two numbers at the bottom. The Cds for the two cars.Overall the Civic Hybrid experience a grand total of just shy of 6kgs of drag less than the stand Civic at 100 kph.
 But then your car isn't the standard Hybrid either. You've got a wing on the rear and some pretty schmick wheels. Those aren't going to have the same characteristics as the Hybrid. You therefore can't claim the whole .04 decrease in Cd.
 you know what ? civic Hybrid can get 0.4 cd lower that FD by :
 1. undercarriage cover
 2. Ducktail spoiler
 3. Lower car height
 4. aero model rims
 
 source :
 http://www.civicfd-sg.com/viewtopic.php?t=15552
 
 
 
	
		
			
			
				
					  Originally Posted by Havocwreaker   My main point is that unless you cruise everywhere very fast, the fuel savings you'll see are negligible. But even if you weren't after fuel savings, but increased downforce. I'd wager that the increases would be tiny. The under carriage tray wouldn't promote pressure gradients in order to produce downforce. 
	so which ones is your main point here ?
		
			
			
				
					  Originally Posted by Havocwreaker   My original point was that I didn't believe the improvements made to your car would offer large performance increases.   btw
 
 
 
	looks like i just copy + paste my previous post
		
			
			
				
					  Originally Posted by dmx   1. the covers made the bottom more smooth hence reducing some moving air trap at the under carriage2. the car is alittle more quite while driving fast
 3. Fuel consp. improve
 and the main purpose is to smoothen the airflow underneath, to reduce drag.
  
 anyway, Holden HSV releaved to put this undercarriage cover on 2010 HSV model to get better aero for get better FC at the end. need scientific from them ?..lol they said, they CAN'T put hybrid engine on any HSV or at least there's NO hybrid engine for V8 5.0L engine
  
 
 
	and about your studying :
		
			
			
				
					  Originally Posted by Havocwreaker That's correct and I'd hardly disagree else I wouldn't end up with a job (I'm studying Aerospace Engineering). http://en.wikipedia.org/wiki/Automotive_aerodynamics
 
 Automotive aerodynamics differs from aircraft aerodynamics in several ways. First, the characteristic shape of a road vehicle is bluff , compared to an aircraft. Second, the vehicle operates very close to the ground, rather than in free air. Third, the operating speeds are lower. Fourth, the ground vehicle has fewer degrees of freedom than the aircraft, and its motion is less affected by aerodynamic forces.
 
 last ;
 so you think ferrari/porche/Civic hybrid/Camry hybrid/FD2R/FN2R (comf. by LD mart) have this stuff only for water guard ?...lol
 
 cheers
 
				
				
				
					
						Last edited by dmx; 29-10-2008 at 07:42 PM.
					
					
				 
	
		
			
				
					29-10-2008 10:09 PM
				
			
			
				
					#2060
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							I really don't won't to continue this argument in public. It's just dick waving and makes both of us look like twats. I'll PM you my IM address and I'll explain my points without internet-ego inflating our points.
						 
	
		
			
				
					29-10-2008 10:25 PM
				
			
			
				
					#2061
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							in the end, the price for what dmx paid in my opinion does not worth the money for what he will get. i can bet the fuel savings will be really small unless he drives really fast all the time and by doing that it will confume more petrol anyway. again, like the rear wing, its for race cars driven on race courses and of minimal use for day to day driving. at least the wing make ur car look good but u cant even see the cover...
						 
				
				
				
					
						Last edited by parraboi; 29-10-2008 at 10:28 PM.
					
					
				 
	
		
			
				
					29-10-2008 10:40 PM
				
			
			
				
					#2062
				
				
				
			
		
	 
		
		
			
				
				
						
						
				
					
						
							yeh its a waste of money mod, but so are alot of mods, people still do em coz they like it. let it be.
						 
	
		
			
				
					29-10-2008 11:34 PM
				
			
			
				
					#2063
				
				
				
			
		
	 
	
		
			
				
					30-10-2008 12:51 AM
				
			
			
				
					#2064
				
				
				
			
		
	 
		
		
			
				
				
				
					new
				
					
						
							i am new does anyone install nice 17" inch wheel on there civic,any brand is good???
						 
 
	
	
 
	
	
	
	
	
	
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