Whats the difference?

1. LSOfreak Saxperience Addict Joined: Jan 2008 west london Posts: 13810

   #1 9th June 2012, 19:03

   on my brothers 1.5 diesel animal, it came with the air feed like this...
   
   
   
   so i put on a spare one of these..
   
   
   
   my question, whats the difference between having one or not having one? does it affect fuel efficiency?
2. user_20080 Saxperience Hardcore! Joined: Dec 2007 smurfland. Posts: 17346 Ex saxo owner.

   #2 9th June 2012, 19:14

   Well in the 2nd pic thats how it should be like,the idea being that could air gets directed in from the slam panel.Having it without the inlet piece I guess would run the risk of having heat radiated from the engine getting into the filter system.Actual fuel economy wise I think it would be marginal as long as the engine is well maintained.
3. LSOfreak Saxperience Addict Joined: Jan 2008 west london Posts: 13810

   #3 9th June 2012, 19:19

   someone told me that cold air into the induction improves performance, but warm air improves fuel efficiency. Is this correct as ive never heard it before?
4. rich112 Saxperience Forum Bum Joined: Jul 2009 Kent Posts: 4207 Mango cammed furio vts

   #4 10th June 2012, 09:57

   Never heard that about warm air for efficiency :/
5. user_34323 Saxperience Post Whore Joined: May 2009 ringwood Posts: 6305 suzuki swift 1.2 sz3

   #5 10th June 2012, 09:59

   How can warm air improve effeincy? Cold air, most combustion o fuel in chamber. More economy :/
6. williamanderson31 Frequent Poster Joined: Dec 2010 Bourne, Lincs/Hatfield Posts: 829 Renault Megane 1.9Dci

   #6 10th June 2012, 10:30

   not sure about the bigger engines, but the 1.1 have a valve so when the engine warms, it opens a valve to let air from the manifold enter
   
   I presumed this was for efficiency or something - dont know why else it would be done
   
   As seen in the pic below circled in red
   
7. jasonmayall Established Member Joined: Mar 2011 Birmingham Posts: 2148 Rover BRM, Rover 800 Coupe, Mk6 golf.

   #7 10th June 2012, 11:45

   Quote:

   Originally Posted by williamanderson31 not sure about the bigger engines, but the 1.1 have a valve so when the engine warms, it opens a valve to let air from the manifold enter I presumed this was for efficiency or something - dont know why else it would be done As seen in the pic below circled in red

   It's a thing they used to do on older cars,it takes the heat from the manifold to help warm the car up, stops using the heat when it's warm and switches to the cold air.
8. monka Established Member Joined: Sep 2010 Posts: 1368

   #8 10th June 2012, 11:59

   as above you got the wrong way round, it take manifold heat when the car is cold to help the engine warm up quicker
9. LSOfreak Saxperience Addict Joined: Jan 2008 west london Posts: 13810

   #9 10th June 2012, 12:25

   k cheers guys. i was just wandering if there was a reason the previous owner removed the air scoop by the slam panel. Guess its staying on then
10. williamanderson31 Frequent Poster Joined: Dec 2010 Bourne, Lincs/Hatfield Posts: 829 Renault Megane 1.9Dci

    #10 10th June 2012, 12:50

    ahh ok, i had wondered what the reason was, thanks
11. monka Established Member Joined: Sep 2010 Posts: 1368

    #11 10th June 2012, 13:31

    Quote:

    Originally Posted by LSOfreak k cheers guys. i was just wandering if there was a reason the previous owner removed the air scoop by the slam panel. Guess its staying on then

    probaly taken off during somesort of repair and lost/not put back on
12. axsaxoman Saxperience Forum Bum Joined: Jan 2003 Scotland Posts: 3380

    #12 11th June 2012, 16:51

    the hot air feed is stop induction icing in the winter when air is damp and cold
    sped up the air through a venturi(t/body0 and temp will drop to a pint where it can form ice in the t/body .
    thats the only reason for hot air devices which always have a thermostatic flap built in.
    
    cold air --denser air -will always give more power from a given amount of fuel ,so even for economy cold air will work better than hot air .
    for best economy run the water temp as hot as possible --then more of the heat --power -from the combustion will go into pushing the piston down and not be wasted heating up the block just to be cooled by the rad --but its a fine line .
    
    the biggest difference you can make to economy on a std car is the driver .
    I run a citroen c-crossrr -- chelsea tractor- and with my best attempts at economy driving i can get it up to 52mpg --but normal driving its around 38-- thats a big margin just by not racing up to the junctions and braking --just anticipate when you will need to slow down and back off throttle so you do not convert all that energy in heat in the brakes +tyres,and of course travel at a slower speed (50mph instead of 70+
    If i go at 80 its down to 32mpg on country roads -motorway its 36. wind resistance( drag) goes up by a square of the velocity --that why loads of 150bhp cars with do 140mph --but you need 5-600bhp to get close to 200mph--and a slippy shape

    1 user thanked this post: LSOfreak