Landracing Forum

Tech Information => Safety => Topic started by: 631 on June 20, 2014, 10:10:01 PM

Title: Aerodynamics
Post by: 631 on June 20, 2014, 10:10:01 PM

There is a nice simple to understand article on calculating CP and CG for lsr vehicles in the tech and FAQ section of this website.  It was written by Bill Dube' and Eva Hakansson who campaign the electric side car streamlined motorcycle and are engineers as well.  If an airplane exceeds its design limits in yaw, pitch or bank (roll) it may stop flying.  If a lsr vehicle exceeds its design or safety limits in yaw, pitch or roll it may start flying.  The 'numbers' as Jeff states are useful tools in helping us understand where those limits may be for our hot rods that we strap on every summer.  Running in a stiff cross wind if the steering wheel has to be turned down wind to stay on the track then the CP is probably behind the CG and the back of the car is being pushed down wind.  If the steering wheel has to be turned up wind to stay on track- don't go any faster.
Thanks for participating in an important discussion.

Title: Re: Aerodynamics
Post by: SPARKY on June 24, 2014, 01:16:00 PM

Have you met "THE SLOT"  :?

Title: Re: Aerodynamics
Post by: Stan Back on June 25, 2014, 12:12:19 PM

Second run ever.  Didn't get me, but it was close.

Still don't know if it's real or fictional -- I'm betting on real.

Title: Re: Aerodynamics
Post by: SPARKY on June 25, 2014, 12:57:26 PM

oh it for real all right 

when I run that track with a West wind I have been known to aim West of the upwind mile marker-- never have been in danger of hitting the upwind one---I try to aim upwind enough that I make no steering correction as I get moved across the track in "THE SLOT" 

Ps I have had to make steering corrections to not hit the downwind mile marker.

Title: Re: Aerodynamics
Post by: wobblywalrus on June 26, 2014, 02:04:27 AM

Is the slot a west wind across the middle of the track when there is a lot less breeze at both ends?

Title: Re: Aerodynamics
Post by: SPARKY on June 26, 2014, 09:45:23 AM

WW 
spot on--the cross wind comes through the little "notch, pass or valley" to the West of the track closest to the pit area .  Usually it "flows or blows" between the 3 and the 4

Title: Re: Aerodynamics
Post by: tauruck on June 26, 2014, 10:16:29 AM

Will it be blowing next year???? :evil:

Title: Re: Aerodynamics
Post by: Seldom Seen Slim on June 26, 2014, 10:21:59 AM

No, this being an even-numbered year -- the wind will be sucking from the east side.  It blows from the west during odd-numbered years. :evil:

Title: Re: Aerodynamics
Post by: SPARKY on June 26, 2014, 11:07:22 AM

LOL   :cheers:

Title: Re: Aerodynamics
Post by: Old Scrambler on July 01, 2014, 03:37:52 PM

except for LEAP-years :lol: