Billy Shope page 18

[LowBuckX]

Been playing with your calculator on page 18 but Im not sure on some thing.

calculator assumes my odd link is the lower link. But My Odd link is the upper. So I dont know how to use your calculator with my set up... any help would be great.

[LowBuckX]

bump for Billy

[BillyShope]

You jumped right into the spreadsheet without reading the instructions above. The odd link can be either above or below.
http://www.racetec.cc/shope

[LowBuckX]

Hmm Ive got something wrong Help.

length of odd link = 18.75

symmetrical link length = 25

offset of odd link = 1 (as close to center as spread sheet allows)

effective rear tire radius = 14 (having trouble with this

axle ratio = 3.55

weight of car with driver = 3500

weight of rear axle assembly = 250

center of gravity height = 18

wheelbase = 110

symmetrical link lateral spacing = 40

desired % antisquat = 50

_____________________________-


ODD LINK REAR MOUNTING POINT

distance forward from rear axle centerline = 0

vertical distance from track surface = 18

SYMMETRICAL LINKS: REAR MOUNTING POINTS

distance forward from rear axle centerline = 0

vertical distance from track surface = 5


----------------------------
ANSWERS


VERTICAL DISTANCES FROM SHOP FLOOR TO FRONT OF LINK
"Odd" Link 0.35 Symmetrical Links -17.93
(Am I reading this correct that the spread sheet wants me to burry the front eye 17.93 inches into the track surface and odd link .35 up)

INSTANT CENTER HEIGHT-.89


LINK LOADS AT 1G ACCELERATION
Left Link of Symmetrical Pair 8081 pound compression

Right Link of Symmetrical Pair 8341 compression

Odd Link
14414 pound tention..


Im still getting more acceptable answers from page 13 I know its a 4 link calculator but its giving me 65% antisquat 80.7 inches from axle center and 9.3 inches high instant center

[LowBuckX]

JUST A PIC i FOUND TO HELP ME... i SHOULD JUST SCALE A DRAWING ON GRAPH PAPER i COULD BETTER UNDERSTAND i GUESS...

ps im NOT YELLING MY STUPID KEYBOARD WONT LET ME UNLOCK CAPS LOCK RIGHT NOW LOL

https://static1.pt-content.com/images/pt/2009/08/0908or_08_zmulti_link_system_basisinstan-1.jpg

[BillyShope]

Note the second paragraph in the instructions:

"This is an asymmetric trailing 3 link arrangement which, during forward acceleration, completely cancels driveshaft torque, thereby providing equal rear tire loading for maximum acceleration. There are 2 symmetrically situated links and a third "odd" link which is offset from the car's centerline (to the right)."

By using only one inch of offset, you've made the suspension essentially symmetric. This is why you get the strange answers. It is impossible to achieve equal rear tire loading with a symmetric suspension. You must have either an asymmetric rear suspension or asymmetric front spring rates.
http://www.racetec.cc/shope

[LowBuckX]

I guess this is lost on me because the Lateral Dynamic and Morrison 3link is a symetrical design and Ive not heard of the spring requirement that you are talking about.,


I tryed to offset the odd link but it still buries the lower links into the negatives and upper link near vertical mounting....

[BillyShope]

...the Lateral Dynamic and Morrison 3link is a symetrical design....
Yes, and neither of these provide equal rear tire loading during forward acceleration.

Maximum performance is achieved from a tire pair with equal loading, but, if you can't find room for the necessary offset of the odd link, use the 4link spreadsheet to achieve a reasonable design. At least, you won't be any worse off than you would with the kits you mention.
http://www.racetec.cc/shope