DAVE BOOS (Offline)
#1
8/3/15 12:17 PM
So in an effort to try and tighten up the front end of the car to get it to turn a little better exiting corner I moved front axle to the left in the car a 1/2" which seems to have made the back end of the car so loose my kid can barely drive it? With no other changes in the car being made is that possible for that to happen? We are running wingless. 2012 Fab Tech Lightning Sprint. Thanks for any info! Dave
badcoupe (Offline)
#2
8/3/15 12:30 PM
how many degrees of camber are you running? Back your front end adjustment up a bit. How high do you have the panhard bar upfront?
TQ29m
(Online)
#3
8/3/15 12:52 PM
I guess I'm a bit unusual, I run mine centered, the panhard pretty much level, and only about 4 degrees of camber, just enough that you still have a feel of the track, turns really good I think! Oh, and about 3/8 lead with the RF! Bob
"Being old, isn't half as much fun, as getting there"! Ole Robert I!

Hotshoe65s (Offline)
#5
8/3/15 5:47 PM
I am not a sprint car expert nor will I claim to be an expert on chassis dynamics, but I think I can help a little here. I think you were on the right track moving the axle. However, instead of shifting it to the left, put it back and just pull the right front forward .5" or so. That lengthens the right side wheelbase relative to the left. Late model and modified guys do the same thing by building it into their frames. It helps the car turn better on entry.
TQ29m
(Online)
#6
8/3/15 5:51 PM
That's what I said, within an eighth of an inch! Bob
"Being old, isn't half as much fun, as getting there"! Ole Robert I!

Jim Gardner (Offline)
#7
8/3/15 9:57 PM
You need to align the axle so that the panhard-to-axle bolt is directly above the left side frame rail and leave it there. Moving that around changes the characteristic of the car too much throughout the entire corner. It may alleviate your problem on entry, but cause the car to do something else on exit. Put the bolt connecting the panhard bar to the chassis along the centerline of the axle at ride height (make certain the driver is in the car). Then go to work adjusting the car with bars, shocks, wheel spacing, and ride heights.
Jim Gardner
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DAVE BOOS (Offline)
#8
8/4/15 10:50 AM
Ok guys I looked at my setup and I have been running about 12 degrees caster, panhard bolt was about 1/2" above center line of axle, I had no lead in car. I moved front axle back to the right were it was at before, dropped panhard bar till it was level with center line of axle, backed off some caster to 10 degrees, put 1/4" of lead in it. So I guess we will see what happens next race day. DAD I do have Steve Smith setup book for mini sprints but its mostly winged setups, we run 1/2 season winged 1/2 wingless. Thanks guys for help!
Jim Gardner (Offline)
#9
8/4/15 11:45 AM
The caster is killing you. Same thing happened to me, was fighting tight tight tight could never get the car to rotate. Reset my caster to 0 degrees and was junk loose without changing anything else. Found a happy medium at about 4-5*.
With a ton of caster it makes turning the wheel a physical chore. Sprints and midgets run that because they have power steering and it helps transfer weight with steering input. The lightning sprints can't do it unless the driver is the Hulk.
Jim Gardner