Ballast Equations

[jl222]

  Hotrod... You should have reminded me about this equation when I bought that nice foto from you.

  As far as traction goes we hat a 21/4 time of 280 with a 294 3 mile time when the piston blew right at end of the 3rd mile with an indicated speed of 318 mph at 7000 rpm, This took 50 sec from 1st applying throttle.

 More weight would help at the start because in low gear tps was 31% max.. 2nd gear 44%... 3rd 50%
4th gear 100% with no tire slip but, instead of more weight I would rather have a variable spoiler [like the Chaperrals had 40 yrs ago]

      JL222


                                   

[iskipnw]

This whole thread was very enlightening.  I am very impressed and humbled by all the brainiacs out there.  I am so glad that I did not experience floating mountains….highway…..starting line………during my maiden voyage this year at Speedweek.

[panic]

Remind me: is fixed ballast required, or is "restrained" (can move, but not freely) acceptable if safety is OK?
I'm sure some see where I'm going...

[WOODY@DDLLC]

Since ballast changes CG I thought I would add this here. (Also posted in parachute thread.)

[iskipnw]

Ok, i am now preparing for Speedweek 2011 and have to report on years one and two.  During the maiden voyage I had a theoretical value for ballast and was unable to install the desired amount.  At 172mph I experienced Cd = traction.  I still had plenty of gear and engine.  The post speedweek analysis using various models, some provided on this thread (thanks you all), and pone that I developed on my own, was within 6% of the value I experienced when I held my actual Weight and Balance constant. 

We subsequently added the appropriate ballast for speedweek 2011 and achieved 203 mph.  This year we are 66 days out as of this post and ballast is fixed....on to other variables.