Home Forums Road Racing Rear Diffuser

Viewing 5 reply threads
  • Author
    Posts
    • #13050
      George Sunderland
      Participant

      With talk of Daytona, does anybody make a rear diffuser to put into a full floor?  I’ve made them myself in the past but its a lot of work and they crack easily when I do them.  I know road racing is in decline but seems like there would be a market for the handfull of  laydowns and superkarts running.

    • #13051
      Brian Wilhelm
      Participant

      I experimented with a couple of different designs, but I couldn’t get any gains.

    • #13120
      bo rougeou
      Participant

      Isn’t there a formula to use for the relief that is built into the rear?  What do you call that thingie?

    • #13162
      Brian Wilhelm
      Participant

      <div class=”d4p-bbp-quote-title”>Chris Reinhardt wrote:</div>

      Brian Wilhelm wrote:
      I experimented with a couple of different designs, but I couldn’t get any gains.

      They don’t work very well without a rear wing :)

      That certainly explains that!

    • #13305
      Peter Zambos
      Participant

      2 questions.

      Why would a diffuser not work well without a wing?  My grasp of aero suggests that if you were considering a rear wing, you wouldn’t have to any longer after putting in a diffuser.

      Question two is: if you want a cheap, easy and perhaps more durable solution in place of a homemade diffuser, couldn’t you put in a row of small naca ducts into the belly pan at the rear?

    • #13327
      Chris Reinhardt
      Participant

      I really wish the quote button worked……..

      First off, air passes above and below, as well as each side, so a wing is affective above the car, and a diffuser below, so one will work without the other somewhat, but neither replaces each other.

      A diffuser in order to work as designed needs to do several things.  One to slow down the speed of the air, and two speed it back up again.

      You can’t use a NACA duct to vent the air into the body work, that would be like a parachute under the car.  It’s designed, or should be designed to work like an airfoil, faster moving on top, slower moving air under equals downforce.  If you drilled a bunch of holes in the wing, besides the turbulence, you wouldn’t have a good separation between the faster and slower moving air.

      Not having a wing means there’s lots of turbulence behind the car messing up how the air comes out of the diffuser, making less effective and giving it more drag….

      Hope that helps….

      CR

       

      Chris Reinhardt

      CR2 Motorsports

      http://www.cr2motorsports.webs.com/

      XV Racing Products

      http://www.xvengineering.com/

      ­­

    • #13119
      Chris Reinhardt
      Participant

      Brian Wilhelm wrote:
      I experimented with a couple of different designs, but I couldn’t get any gains.

      They don’t work very well without a rear wing :)

      Chris Reinhardt

      CR2 Motorsports

      http://www.cr2motorsports.webs.com/

      XV Racing Products

      http://www.xvengineering.com/

      ­­

Viewing 5 reply threads
  • You must be logged in to reply to this topic.