View Single Post
  #453  
Old 16-06-2011
SlowOne SlowOne is offline
Mad Member
 
Join Date: Oct 2007
Posts: 1,549
Default

We had one driver who uses a steerwheel, but used sticks for the event. In all his stints he didn't lose us any laps on second!!

Chassis - we've discussed it and don't mind either way. The HPI chassis is all plastic and has a lot of give in a shunt. Anything with a composite chassis will have much less give and tend to transfer loads to the suspension and uprights. Just a thought...
Bodies - we'll all have to buy every body and test it to find the best one, then we'll all stick to that one. Why not just have one body stipulated as we did last week and then costs are down and we are all in the same boat?

My 2p on motors. E=1/2mv2 (E equals a half times M times v squared). That means the kinetic energy of any object is its Mass (weight) times the square of its speed. For our cars weighing 1.6kg travelling at 9 metres per second (about 20 mph) it has an energy of about 0.6kj (kilojoules, but that's not important). If you up the speed to 30 mph, then the energy is 1.5kj, or 2.5 times what it was at 30% less speed.

Why is that significant? Because when you hit something, all that energy has to be dissipated. And the more there is to be dissipated, the more work it will do. And the more work it does, the more likely it has enough to break something. Depending on where you hit things will depend on what breaks, but one can imagine what effect this will have if you hit a corner marker with a front wheel with 2.5 times the force you has before...

If we go to something much quicker than a 20T, then every crash will take much greater toll on the cars and the track barriers. John may not need a fund just for a new carpet, he might need all new barriers the following week! The impact on the cars means that we will all need more spares since the chances of breaking something are 2.5 times greater for a 30% increase in speed. And that's before we factor in the increased skill and mental capacity needed to drive a car 30% faster with 14 other cars on the same bit of real estate!

Please think very carefully indeed before we select a motor that is any faster than the one we have used. 17.5 should be fine, and 13.5 may mean some people having to retire their car before 24 hours is up simply because they have run out of spares. It is my 2p, but I hope its value is not lost on you all. Thanks.
Reply With Quote