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SunnyHouTX
2010 Texas Worlds Top Fuel and Outlaw 10.5 Champ
 
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02.17.2009, 03:41 PM

What you have calculated is continuous power. The set up I mentioned will peak at about 1100W due to voltage draw down as well as the shear amount of current it will pull on initial start up. Drag racing puts conventional thought out the door. And you don't really want "all the power you can get", mostly because the limiting factor is almost always the available traction. Traction is pretty hard to control with a low Kv, high voltage system as the torque is too much to control.

Just to illustrate, here is a look at the draw down of a 3S Thunder Power 3300mAH 25C/50C pack within one pass I made:



We run with LVC turned off so as not to mess with the flow of current, if any body is wondering how the pack went below 6V. It only recovered to about 9V at the immediate end of the race but, normalized around the 12V mark afterward. This is why it's very important to use high C rated packs, so that the recovery phase is quicker and the end voltage is as high as possible for top end RPMs.

I have no idea what the real power output of my dragster is since there is no way to measure the current demand in it. I estimate it to be in the 200A range, so a good estimate will be around 1800W or higher. My Litespeed dragster does the 132ft at a best ET of 1.45s @ 88mph+, just to give an idea of what's going on.

A shameless plug here, but check out my website in my signature to see my race cars and such.


Quickest 1/10 Top Fuel Dragster

Last edited by SunnyHouTX; 02.17.2009 at 03:50 PM.
   
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What's_nitro?
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02.17.2009, 05:38 PM

Quote:
Originally Posted by SunnyHouTX View Post
What you have calculated is continuous power.
Oops.... So drawing the cells down that far for such a short period wont hurt them? Have you tried adding more caps to the system?
   
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