So anyway aerodynamics

  1. Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma
    #1
    Seeing as the other thread got locked lol

    The saxo has a pretty low drag coefficient as standard.

    What ideas do you all have to improve aero?

    After removing spare wheel, there is a big low pressure area under the boot, it is worth cutting the centre out of the rear bumper as it will create quite a lot of drag, and possible lift, whereas teh low pressure area should "suck" the car down into the tarmac at the rear.

    Removing the rear spoiler would help a little bit, it is too small to be doing much good, it's just there to look cool.

    Some sort of undertray for the engine as well is worth a try.
  2. Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS
    #2
    im contemplating manufacturing a plate which will curve from approx 100mm below the fuel tank, up to a letterbox cutout in the rear bumper, with vertical fins.

    either that or a flat plate from the bottom of the fuel tank to the bottom of the bumper, again with vertical fins.

    anything's gott abe better than the air dam the rear bumper creates when the spare wheel is removed.
  3. Saxperience Hardcore! Joined: Dec 2005 e-hollywood Posts: 17160 toyata hilux
    #3
    yes an undertray. seen one somewhere. also take you windmirrows off ftw
  4. Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma
    #4
    Just cut the damn bumper, less weight, better aero

    It's all part of the plan. My car looks like a heap anyway, and the new spray job isn't going to be the best so might as well bastardize it!
  5. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #5
    wasnt don onto something? sure i seen him with corigated plastic where spare wheel would be? just as a rough prototype so to speak?

    also i did read about someone making a mdf front splitter?
  6. Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma
    #6
    I need to speak to some people i know who do plastic moulding, get a saxo engine bay undertray made up,

    Thing is most cars with undertrays have exhaust at rear of engine, having manifold on a saxo on the front of the engine will melt a plastic tray easily, have to think about that one. Aluminium isn't too heavy i guess?

    Roffle @ MDF splitter and corrugated roofing undertray

    The S1600s just use an extended splitter. Might rape a broken vt bumper to extend my splitter with...
  7. Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS
    #7
    engine undertray would be pointless, the additional heat generated from no ventilation to this area would cause problems - unless you get bonnet lifters y0.

    the rear is where the real gains can be made i think
  8. Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma
    #8
    All modern cars use engine undertrays for a reason, there is a fair bit of drag caused by the underneath of the engine bay! There wouldn't be that much difference to the cooling of the engine tbh either. Although my bay gets fucking hot as it is! At least it'd stop me leaking oil everywhere

    You like the rear end do you pauline?
  9. Saxperience Forum Bum Joined: Jun 2005 Potters Bar United Kingdom (England) Posts: 2749 T/B'd VTS
    #9
    love it baby.

    extended front air dam, rear undertray = 180mph in second in a vtr. honest
  10. Saxperience Hardcore! Joined: Dec 2005 e-hollywood Posts: 17160 toyata hilux
    #10
    get it on a wind tunnel
  11. Saxperience Post Whore Joined: Feb 2006 dudley United Kingdom (England) Posts: 6790 106 gti/ SEAT LCR
    #11
    i believe that on a normal powered car theres not too much point as you wont be getting to the speeds quick enough and high eneough to warrant aero aids.

    on a tuned car though id say there is a nice gain to be had up the rear as pauline said.
    the underneath of saxo/106 isnt too bad in my opinion and under engine would be good to sort out but like alex said how low the manifold is would be another issue to get round.
  12. Saxperience Post Whore Joined: Aug 2004 Kunt & Sorrey Posts: 5763 Rep mobiles & Joes ma
    #12
    There's a wind tunnel near me on the A26, sounds awesome driving through it with bodies
  13. Saxperience Forum Bum Joined: May 2007 Posts: 4857
    #13
    Been tried many times before and going flat bottom does very little. You would struggle to make it light enough to see any read advantage on the track.

    You will also struggle to get a Saxo low enough to use ground effect unless its a pure track car. As in a popper track car racing on popper tracks.

    If your willing to go radical you can always cut the roof, pillars, windscreen and rest of the glass off. Then stick as lower seat as possible in. You would be best to stick a tarp over everything but the drivers seat. That should see a nice improvement on your co efficiency.

    But all really depends if your after loosing drag or gaining negative lifts.
  14. Saxperience Post Whore Joined: Mar 2003 United Kingdom (England) Posts: 7064
    #14
    Z-cars built one with a chopped down roof, not the best looking saxo
    http://www.zcars.org.uk/saxo/index.htm
  15. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #15
    that grey one with the vtec engine hasnt had a roof chop has it?
  16. Saxperience Addict Joined: Nov 2006 A farm shed in Aylesbury Posts: 14916 Corolla AE86 Peugeot 205 B18C (in bits)
    #16
    lots of things that you can look at with aero but you have to be realistic about the gains you will get. You won't build a saxo F1 car but, everything, when done right will give you an advantage be it in stability / top speed / cornering.

    Can forget ground effect. You could not get a saxo running low enough to the ground to get a useful benifit.

    The front bumper is a good place to start. Air passing under the car meets the exhaust / engine / gearbox etc and those parts obstruct the airflow which increases turbulence creating drag. Also slows the air down right where it should be fast moving giving you lift!

    To get round this you'll have to look at the front spoilers on touring cars for inspiration and a smooth undertray would help. Problem is again that on a road car you are limited by ride height and the need to get over kerbs, pot holes and the likes

    Ideally it needs to start max a few centimeters from the ground. like this


    can't find many figures for the effect of an undertray on the web
    got this picture in my photobucket that shows what Audi did to the road going A2


    can see the figures on the picture of how much each element reduced the Cd

    work looking at where air is ducted in too as if left to its own devices it will cause turbulence and lift. The front bumper and radiator are prime areas for looking at BUT on a compact car like the saxo you are limited by space. Ideally air should be ducted in and ducted out.. like the lotus exige

    A simpler thing you can do is block up all the holes in the bumper not directly cooling something. Just creating a good air duct in to the rad will aid cooling.

    haven't even touched on spoilers, winglets, panel gaps, bodywork, wheels etc etc.. Need some breakfast though and the fiancee wants some attension so will have to be another time
  17. Saxperience Forum Bum Joined: Jan 2008 Down't road from Sheffield Posts: 4641 Was:16v 106 XS ..... Now: Import 1.8 MX5
    #17
    Pretty sure I read about someone who'd made a rear undertray/diffuser somewhere, mighta been the Rallye Register.
  18. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #18
    tape the gaps up between the bodywork panels... probably the cheapest, lightest and simplest method of reducing the drag.

    Or go further still and cover up the grilles y0... might heat up the engine a bit too much but it'll be slightly more efficient/powerful for a brief time as well, which is nice, before going too hot and destroying itself.

    you may think I'm a cunt for saying this but actually having clean paint work will help a bit.

    Perhaps obvious but the base models (3-door) have a slightly lower Cd than the VT models.

    Remove the wipers - or if you fancy staying on the right side of da law... modifying then in someway so they're better streamlined.

    Lose the aerial

    flat undertray would be nice but I think the weight penalty would outweigh (budum tishh) the benefits - you can't really do a cardboard version as it's gotta be rigid otherwise the aerodynamics will be just as naff anyway.

    that's all I can think of at the moment.
  19. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #19
    Quote:
    Originally Posted by adsayer View Post
    tape the gaps up between the bodywork panels... probably the cheapest, lightest and simplest method of reducing the drag.
    i did lol

    i did also see this

    y0

    and i lol'd more

    im a style whore, i would of used black tape on black car
  20. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #20
    Quote:
    Originally Posted by Yates View Post
    i did lol

    i did also see this

    y0

    and i lol'd more

    im a style whore, i would of used black tape on black car
    have to log in

    fail.
  21. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #21
    Quote:
    Originally Posted by adsayer View Post
    have to log in

    fail.
    you have my username and password

    negative fail
  22. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #22
    no i don't

    fail resumed
  23. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #23
    Quote:
    Originally Posted by adsayer View Post
    no i don't

    fail resumed
    check that pm

    did you just think i put my name and a random word there for shits and giggles?
  24. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #24
    I thought that was just you talking garbage.

    safe.
  25. Saxperience Hardcore! Joined: Mar 2005 Pompey/Darlo Posts: 31546 MK1 - 1.1 Animal
    #25
    nooooooooob
  26. Saxperience Hardcore! Joined: Oct 2005 Aycliffe Posts: 32205 Saxo VTS
    #26
    were you saying 'nob' iiinnnnnn aaaaaaaa reaaaaalllyy loooonnnngggg wwaaaayyy oooooffff saaaaaayying iitttt

    or just 'noob'?

    either way I'm offended tbh