Let's Talk Aero

Discussion in 'Road Racing Forum' started by antman450, Oct 21, 2017.

  1. antman450

    antman450 TMO Race

    Messages:
    397
    Likes Received:
    260
    Joined:
    Feb 26, 2017
    Location:
    Orange County, California
    I have seen many discussions regarding aero, down-force, drag, etc., but they are all littered throughout other threads. I thought maybe it would be good to have a thread where we discuss these things. This, with the caveat that I don't have thousands to spend on custom carbon parts and wind tunnels.

    I'll start with my current problem, push while at neutral or on throttle during high speed (100 MPH) sweepers. The car is neutral to slight over steer every where else. I like a bit of over steer. So, during a sweeper, there is no change in weight transfer (for the most part) and yet I have a mild push. I conclude that I need more front down-force for a rather simple and fundamental reason:

    If I lift slightly to put a bit of weight on the front, it almost completely goes away, but it is also slower. I cannot induce on throttle over-steer at those speeds because the rear is rather planted. Actually, as I add more throttle, I lose more front grip.

    Certainly, with large, low drag wings, the rear is more addressed than the front.

    So, I have a 4 inch splitter and hood vents. That is the extent of what is working for me on the front. My thoughts are, fender vents, more hood venting if possible (don't want to drop the $$$ on a tiger racing hood right now), side canards, and a 1 inch damn between my splitter and lower fascia. Then some fender splats.

    I would love to hear from some others on their thoughts. @AJHartman I am sure would be able to add some great info to this. @ArizonaBOSS, did you feel that the canards made a noticeable difference?

    So, post on.....
     
    fpGT350 and Grant 302 like this.
  2. RES_22

    RES_22 Rob

    Messages:
    239
    Likes Received:
    235
    Joined:
    Dec 25, 2016
    Location:
    Snowy North
    Possibly a dumb question but....have you corner balanced the thing?

    Is it fuel-load dependent? Worse with a heavier load?

    Have you tried a bit less front rebound?

    Worse in RH vs LH corners?

    Just wondering...rule out the obvious first...
     
    fpGT350 and Fabman like this.
  3. antman450

    antman450 TMO Race

    Messages:
    397
    Likes Received:
    260
    Joined:
    Feb 26, 2017
    Location:
    Orange County, California
    No change with fuel load, right-hand and left-hand the same, messed with dampening, camber, and ride height as well. The car just works so well everywhere else and I can induce throttle oversteer anytime, except at over 100 miles an hour.

    I guess really though, so many people focus on rear downforce, I would like to hear on some more ideas about front downforce.


    Sent from my iPhone using Tapatalk
     
    Fabman likes this.
  4. VoodooBoss

    VoodooBoss Rick Moderator

    Messages:
    20,391
    Likes Received:
    2,776
    Joined:
    Nov 30, 2010
    Location:
    90 Miles East of Sonoma Raceway
    Don’t forget about reducing lift.
     
  5. antman450

    antman450 TMO Race

    Messages:
    397
    Likes Received:
    260
    Joined:
    Feb 26, 2017
    Location:
    Orange County, California
    I’m sorry, I presumed that was implied. But yes naturally, reduction of lift is in a sense an increase in downforce.


    Sent from my iPhone using Tapatalk
     
    Fabman likes this.
  6. VoodooBoss

    VoodooBoss Rick Moderator

    Messages:
    20,391
    Likes Received:
    2,776
    Joined:
    Nov 30, 2010
    Location:
    90 Miles East of Sonoma Raceway
    @Fabman for fender vents.

    The Tiger hood is all about reducing lift and not cooling.
     
    fpGT350 and ArizonaBOSS like this.
  7. ChrisM

    ChrisM No bad days.

    Messages:
    371
    Likes Received:
    351
    Joined:
    May 29, 2017
    Location:
    Japan
    Does the Tiger hood actually create downforce or does it just reduce lift? I would guess that the Trackspec louvers (which I also have) reduce lift but don't create downforce.
     
  8. VoodooBoss

    VoodooBoss Rick Moderator

    Messages:
    20,391
    Likes Received:
    2,776
    Joined:
    Nov 30, 2010
    Location:
    90 Miles East of Sonoma Raceway
    Not sure about creating downforce but it reduces lift which improves downforce.
     
  9. Fabman

    Fabman Project: "Frankenstang"

    Messages:
    2,444
    Likes Received:
    1,372
    Joined:
    Jan 31, 2016
    Location:
    Pleasanton: 1/2 way between Sonoma and Laguna Seca
    Anything that reduces lift increases downforce. Opposite side of the same coin. How much is the question. I see some seriously fast pro race cars using these Trackspec hood vents so I gotta think they know something about them.
     
    Last edited: Oct 21, 2017
    ArizonaBOSS and ChrisM like this.
  10. Fabman

    Fabman Project: "Frankenstang"

    Messages:
    2,444
    Likes Received:
    1,372
    Joined:
    Jan 31, 2016
    Location:
    Pleasanton: 1/2 way between Sonoma and Laguna Seca
  11. Fabman

    Fabman Project: "Frankenstang"

    Messages:
    2,444
    Likes Received:
    1,372
    Joined:
    Jan 31, 2016
    Location:
    Pleasanton: 1/2 way between Sonoma and Laguna Seca
    "Anything that reduces lift increases downforce"
    Well maybe that isn't exactly true...there is static weight, then there is lift, then there is downforce...lift lightens the nose while down force adds weight (from a reference zero-or static weight) so my over simplification was sloppy. There is a difference, but basically you have to lessen one to get the other. That's probably a better way of saying it.
     
    fpGT350 and ChrisM like this.
  12. ChrisM

    ChrisM No bad days.

    Messages:
    371
    Likes Received:
    351
    Joined:
    May 29, 2017
    Location:
    Japan
    That's more along the lines of what I was thinking.
     
    Fabman likes this.
  13. antman450

    antman450 TMO Race

    Messages:
    397
    Likes Received:
    260
    Joined:
    Feb 26, 2017
    Location:
    Orange County, California
    That’s what I have. Not sure how much better a tiger racing hood actually is. Their hood has a great design and bigger vents but not sure how much more effective. I actually wish Trackspec made more vents for my 2011 mustang hood. Wish they made fender vents too. May go DIY.


    Sent from my iPhone using Tapatalk
     
  14. antman450

    antman450 TMO Race

    Messages:
    397
    Likes Received:
    260
    Joined:
    Feb 26, 2017
    Location:
    Orange County, California
    I certainly have not problem cutting into my car. Lol


    Sent from my iPhone using Tapatalk
     
    Fabman likes this.
  15. ChrisM

    ChrisM No bad days.

    Messages:
    371
    Likes Received:
    351
    Joined:
    May 29, 2017
    Location:
    Japan
    The lip around the vents of the Tiger hood create a pressure difference that actively draws air out (not sure if that's the correct description), whereas the Trackspec louvers lack that. I recall seeing someone do a string test on their hood not long ago where they cut the holes in the hood and then tested it with and without a lip in front of the hole and it was a noticeable difference. Without the lip, the string laid flat against the hood. With the lip the string stood up perpendicular to the hood before flattening out. The Trackspec louvers may have some of that effect, but I would guess that if they made the first louver stick out into the airstream further than the others it would make a dramatic difference.
     
  16. dabossinnne

    dabossinnne TMO Addict

    Messages:
    545
    Likes Received:
    84
    Joined:
    Aug 6, 2012
    Location:
    Omaha, NE
    Check out this old Ford Racing TV vid of early B302S wind tunnel testing w/ a Tiger Racing hood. Air extraction through the Tiger hood looks to be quite substantial and I would think greatly aids in reducing front end lift.

     
    fpGT350, ArizonaBOSS and Fabman like this.
  17. Fabman

    Fabman Project: "Frankenstang"

    Messages:
    2,444
    Likes Received:
    1,372
    Joined:
    Jan 31, 2016
    Location:
    Pleasanton: 1/2 way between Sonoma and Laguna Seca
    "A wickerbill"
     
    ArizonaBOSS and ChrisM like this.
  18. ChrisM

    ChrisM No bad days.

    Messages:
    371
    Likes Received:
    351
    Joined:
    May 29, 2017
    Location:
    Japan
    Yeah, that. Something like that in front of the Trackspec vents would probably make a difference.
     
    ArizonaBOSS likes this.
  19. Fabman

    Fabman Project: "Frankenstang"

    Messages:
    2,444
    Likes Received:
    1,372
    Joined:
    Jan 31, 2016
    Location:
    Pleasanton: 1/2 way between Sonoma and Laguna Seca
    Easy enough, maybe I'll experiment with that.
     
  20. ChrisM

    ChrisM No bad days.

    Messages:
    371
    Likes Received:
    351
    Joined:
    May 29, 2017
    Location:
    Japan
    I found the pictures I was looking for. The Tiger Racing hood has this concept molded into the hood whereas the Trackspec louvers don't have this provision but could probably benefit from it. Can't wait to see what you come up with @Fabman .

    19598446_10209144507992190_6441236625656575736_n.jpg 19511611_10209144516352399_853430997053921530_n.jpg
     
    Last edited by a moderator: Oct 22, 2017

Share This Page