I saw this over at PT just now and my machine is locked down so hard by the wife's spy program stuff that it was going to take forever to ask over there so I thought I would ask here??
How does a "Jacob's Ladder" work and install on a Sprint Car??
I figure it is a fancy "Watts Linkage" or Panhard-Bar" or something but just can't visualize how it works is all..
This is the first time I have ever heard of one...
Dec 10th, 04, 06:08 PM
They were used a lot on sprint cars. They work OK if the suspension travel is not too great. You don't see them on other types of cars, they seem to be used when other types won't fit. those circle track guys are really uptight about weight too and the JL's are light.
The JL consists of an upper and lower pair of links connected to a triangular link. The arms act like upper and lower A arms, so you can imagine a mini-front suspension connected from the frame to the rear axle you are pretty close. The upper and lower links have an instant center like your front suspension does and the advantage is, the Instant Center of the links can be long.
Jacob's ladder? Aren't those the things that mad scientists used in their la-bor-a-tories in old monster movies? The thing where an electric arc would travel upward between two poles before flickering out. I've always wanted to make one of those, but never could figure out how. smile.gif
Dec 11th, 04, 05:25 AM
I see the four folded levers/arms, but it doesn't look like the triangle is even there b/c I can't see where it bolts to??
Looks like the levers/arms bolt to the frame on one side and the circular cutout on the triangle goes around the driveshaft or torque tube but how else does it fasten??
The triangle point has to fasten to the rearend somewhere??
Or does the triangle point fasten to the rearend outboard by the axle end??
But it looks to me that a true Watts linkage will allow the rearend to travel vertically AND NOT move side to side like a panhard bar allows it to and IF I have this right, a J/L will too??
Dec 11th, 04, 06:07 AM
The outer point is attached to the axle, way out by the backing plate. It is both a centering and a weight transfer device.
Remember, these cars were ONLY DESIGNED TO TURN RIGHT!****EDIT, OOOPS, I mean LEFT!****
The bar acts as a lever, and will transfer weight to the outside tire on a left turn.
[ 12-11-2004, 08:25 AM: Message edited by: JimM ]
Dec 11th, 04, 11:02 AM
I see it! The triangle is the black thing pointing towards the tire..
Would it lock solid if you had one on each side??
Dec 12th, 04, 04:59 AM
It would certainly bind up really bad, and I think it would kill the effect as well.
I go to see the sprints at rt66 every year, and walk around the pits after the race and talk to people. These are extremely speciallized cars. They got 1000 HP injected big blocks, full custom race engines, and a lot of weird special appl. stuff that you don't see everyday. They turn left only, on DIRT! Suspension travel is only an inch or so, and the outside tire is 3" taller and much wider than the inside.
These things are a GAS to watch! We sit 30 rows up (to keep out of the cloud)at the exit of turn 3. There ain't nuttin like watchin 6 1000 HP cars, 3 wide, completely sideways, coming straight at ya, thowing dirt 200 feet off the rear wheels! (Except maybe sitting right up at the end of the inner fence at the 60' line watching top fuelers, we used to do that a long time ago, can't get away with it now)