Hi all, I have a new (well I have shot once) person predator I got in nov 2003, (great deal from hunters friend and pearson).

I want to find out K-energy and fps all of that, but the one website with the calculator thing needs stored energy/pdf ratio info, 0.5-2 I htink it is. I cannot find this anywhere. Can someone help?

56lbs, 28" draw length, total arrow weight 468.3 grains Carbon Express with Chuck Adams 100 gr spear points , TKO fall away, string has 2 cat whiskers and d loop on it. 85% let off.

I will be looking for a slightly different arrow, mine are a bit heavy/stiff at 6075's.

Thanks

this is the calculator site

http://home.att.net/~sajackson/archery.html

Until somebody plots the draw force curve out, I'm not sure where you could find that info unless Pearson would make it available to you (anc chances are they only do it for a 30" draw and 60 pound draw weight as that is the AMO/ATA standard). It requires some fairly sophisticated equipment to do it right (I.e. not let hysterisis come into play... which will skew the results)

It's much easier to figure out what you want to know by finding a chronograph & a grain scale at a local shop.

here's what I've concluded:

I will try 2-3 types of arrows/tips into a target and see which penetrates best. I can;t really change speed all that much besides my arrows. May be stupid seeming but it may work!

The predator at your setup should be shooting around 215-220 FPS and the KE is roughly 48 ft/lbs.


That is an heavy arrow for 56 pounds but would be great for hunting.


The stored energy would be around 1.1966 for that bow.


EB

thanks eb79...why sell the predator- 3somes are always better!![8D]

jsut because I haven' t ever done this what is virtual mass, and bow efficiency%?????

The only reason it is being sold is the Wife Wont be happy with another one. [:@] It is almost brand new. It was a store stock and it has had a sight and release mounted on it but that is about it. I dont believe and arrow has every been through it since their is no brass nocks or string servings on it. I would make someone a deal on it if they are interested and i have pics of it available.


The effieciency if the amount of energy stored in the cams Potential versus Kinetic ratios. I dont know the exact math but i use The Archery Program and it will calculate it all for you.


EB