Erratic steering just before turn entry

[8184]

Car is a 3 link Superstock/ grand national type car and just before i lift going into a turn car jerks to the right then back to the left . The left jerk is probably caused by me trying to keep the car from hitting the wall entering the turn,either way its complicating my turn entry. anyone have any ideas what could be causing it ? And i know its not a modified but i figure my basic setup is no different than a 3link mod and i cant find any binding in my suspension and my caster camber and toe #s are what i have always ran and ive never experienced this before.

[7uptruckracer]

Sudden loss of rear steer would be my guess. If you have rear steer with your bar arrangements and hike if you lifting and the car is setting down all the rear steer is coming out and it will dart right.

[stock car driver]

bottoming out something in the rear

[rob burgoon]

If your right rear also comes up under power it could be you reduce throttle, right rear comes down, steering you right. Then you reduce gas further and the left rear comes down, eliminating the rear steer and going where your steering wheel is facing (left).

[Dirtmod13]

Car is a 3 link Superstock/ grand national type car and just before i lift going into a turn car jerks to the right then back to the left . The left jerk is probably caused by me trying to keep the car from hitting the wall entering the turn,either way its complicating my turn entry. anyone have any ideas what could be causing it ? And i know its not a modified but i figure my basic setup is no different than a 3link mod and i cant find any binding in my suspension and my caster camber and toe #s are what i have always ran and ive never experienced this before.Check your left and right chassis to rearend measurements vs chassis manuf.'s -we were chasing a loose everywhere condition and just to try it / moved the rr forward too much and it caused what your describing. Fine in corner and exit but when lr finally comes down the axle is pointing left of center. That steers car right. Try just looking down the side and see if the rear tire lines up with the front. Or put a long bar/ straight edge on it.

[drtrkr244]

I have seen a car do something similar because of a too short panhard bar. You have to be careful when going to a short straight bar, as the rearend moves laterally quite a bit esp if you dump the throttle.

[8184]

ok heres whats on the rear end as far as bar angle lr 22 degrees rr 12 degrees the mounting brackets on the rear end have three holes in them, the right rear is in the top hole ( close to the axle tub ) the lr is in the middle hole inch lower than the rr bar lr spring is 250 in front of the axle . the rr spring is 225 on top of the axle . pan hard bar is straight behind the axle and is 32 inches long with 5 inches of split car drives good on the throttle form the middle out till just past the flag stand then it gets crazy and i end up loosing some momentum entering the turn. I did check the rearend to make sure its square and it is.

[Dirtmod13]

ok heres whats on the rear end as far as bar angle lr 22 degrees rr 12 degrees the mounting brackets on the rear end have three holes in them, the right rear is in the top hole ( close to the axle tub ) the lr is in the middle hole inch lower than the rr bar lr spring is 250 in front of the axle . the rr spring is 225 on top of the axle . pan hard bar is straight behind the axle and is 32 inches long with 5 inches of split car drives good on the throttle form the middle out till just past the flag stand then it gets crazy and i end up loosing some momentum entering the turn. I did check the rearend to make sure its square and it is.Have you tried setting right rear back 1/4 to 1/2"?Might have more lr drive that's pushing front end to the right.

[8184]

Dirtmod13, i actually thought about trying that for 2 reasons 1: is exactly as you put it ,could i be getting so much lr drive that the car starts steering to the right? seems to me that that wouldnt be likely that far down the straight but i just dont know 2: if i push the right rear tire back a 1/2 inch when the car comes off the bars it shouldnt be able to steer the car to the right cause i would still have steer trying to turn me left to some degree.

[7uptruckracer]

By change what do you run for a top link/ torque absorber. If you have it too soft it can unload down track and set the car down without your input and cause what your describing as well?

[8184]

Got a quickcar biscuit bar with 2 reds and 2 yellows

[langdonracing48]

I've always been told too much pull bar angle can cause this to happen also. Could try to take a couple degrees of angle out of it?

[setup479point2]

Do you have a locked centersection , or a detroit locker or torsen type ? If its the second type it could be something wrong in it . Just sounds to me like your RR is losing all its drive at that point .

[Dirtmod13]

Dirtmod13, i actually thought about trying that for 2 reasons 1: is exactly as you put it ,could i be getting so much lr drive that the car starts steering to the right? seems to me that that wouldnt be likely that far down the straight but i just dont know 2: if i push the right rear tire back a 1/2 inch when the car comes off the bars it shouldnt be able to steer the car to the right cause i would still have steer trying to turn me left to some degree.You have a heavy lr spring. It could be making the car tight/ pushing to the right when off the bars and car is more at a static state. We moved rr back 1/4 at a time until that went away. It was exactly as you described it. Scary when it turns right just before entering the corner. Imagine this. As your car comes off the corner, it should be up on the lr bar giving it some rear steer. As you go down the straight and slow for the corner the the left rear bar drops and rear steer goes away so if it has too much tendency to turn right this would be a place that you would really feel it

[Anonymous24]

bottoming out something in the rearSadly I agree

[8184]

well took the car out last weekend and and started by adding 1/4 inch RR trail ,problem was still there. Put some new tires on and added another 1/4 inch RR trail, and Problem is gone. I can now drive in smoothly. Thanks for all the Information and help.

[8184]

Haven't checked that since getting it back in the shop, will probably do that Friday before i scale the car again. It should be 106.75 on left and 107.25 on right if we did everything correctly at the track, but regardless of what it is, its working so ill leave it alone. Entry was really good in my opinion and and now next practice we can work on middle off which is already pretty good but i think we could be a a little tighter through the middle and turn exit.