Left side weight loosens on entry... why?

[rob burgoon]

Anyone have a theory on why adding left side weight tends to loosen the car?

[rob burgoon]

Left side weight where or just left side weight? There is a difference.

Just left side weight percentage. Not at a particular end of the car.

[1Blacksheep]

Off throttle drags the car left. On throttle takes a moment longer and speed for the wt to transfer to the Right for side bite. Roll centers,roll couple and CGH plays into it .

[drtrkr244]

Increased load on dirt tires equals more traction....to a point. As track dries out, more weight needs to transfer to right side tires to increase grip. Most racers used to change left side weight for the feature but are now crutching the car with rear end adjs. Mark Bush has been stressing this in DLM mag for several months now.

[blncfn57]

"Left side weight loosens car on entry" is part of the sentence. the other part is "off the throttle"

[rob burgoon]

So, what about extra left side weight makes the car loose when off the throttle?

[blncfn57]

So, what about extra left side weight makes the car loose when off the throttle?

Post #4 touches on it. With more weight on the left side when the tire slows down it will drag the car to the left.

[rob burgoon]

Post #4 touches on it. With more weight on the left side when the tire slows down it will drag the car to the left.

Must be a pretty small effect then? Does it do anything midcorner?

[blncfn57]

Must be a pretty small effect then? Does it do anything midcorner?

Well, of course. Every change in the car effects it differently at different points on the track. It's always a give and take deal. Picking up the throttle too soon or too much mid corner can either slide the nose across the track or cause you to spin out, depending on how hot you approach the corner. The biggest mistake I see (usually by the guys running in the back) is guys not getting the car pointed in the right direction before getting in the gas. Using left side to help the car turn and rolling through the center patiently should result in being able to drive off the corner better. Use less left side (or at least mount weight higher) when track is tacky and faster. JMO, I'm sure some will argue, but to each their own.

[rob burgoon]

Well, of course. Every change in the car effects it differently at different points on the track. It's always a give and take deal. Picking up the throttle too soon or too much mid corner can either slide the nose across the track or cause you to spin out, depending on how hot you approach the corner. The biggest mistake I see (usually by the guys running in the back) is guys not getting the car pointed in the right direction before getting in the gas. Using left side to help the car turn and rolling through the center patiently should result in being able to drive off the corner better. Use less left side (or at least mount weight higher) when track is tacky and faster. JMO, I'm sure some will argue, but to each their own.

Interesting, most of the stuff I've been reading says move the weight up for the slick when you're not getting as much weight transfer as in the tack.

It's a mess trying to figure this stuff out. The GRT and Smith book says rear steer is used for the heavy/tacky to make the car turn, and the Circle track articles say to use rear steer for the slick to keep the tires under you. Amazing that the books agree so little.

[1Blacksheep]

Books can be good and books can be really bad unfortunately. I have a pickup load of them and they contradict each other on most subjects. But that goes for talking to some top notch drivers also . Some of the fastest Cats I know have theories on stuff that actually does not work the way they think . Its frustrating . The only thing you can do is collect all the knowledge you can and take it to the Dirt . Then hope you get it figured out before you go broke . I think I got it know , but know I'm broke ! lol

[rob burgoon]

If the CG is 24 inches high and the width is 70 inches, it looks like way, way more than 3% weight moves from the left side to the right side. So that theory is out.

I should prop up the LR with something to full droop and remeasure corner weights....

[1Blacksheep]

24" ht is just part of the equation . You must factor in the leverage arm created from CGH to the Roll center length as to how much wt is actually transferred in roll from centrifugal force or just thrown as a mass laterally that transfers very little to the outside tire . That's why the short or J bar is adjustable .

[blncfn57]

If the CG is 24 inches high and the width is 70 inches, it looks like way, way more than 3% weight moves from the left side to the right side. So that theory is out.

I should prop up the LR with something to full droop and remeasure corner weights....

guess I'm lost as to what you're trying to prove wrong.

[rob burgoon]

guess I'm lost as to what you're trying to prove wrong.

Proving wrong my own theories about weight distribution and the role of static left side weight. Just trying to look at the suspension from different directions to understand it better.