Carrying the LF

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12-30-2019, 11:03 AM
Cranky

Carrying the LF

I was at 411 this weekend. I was noticing something curious to me in the supers and the crates. The very fast cars were carrying the LF down the straight away and putting it back down on landing in the corner. Now the LF was not a foot off the ground, it was only enough for the LF to stop turning midway down the straights. The cars that were doing this had a tremendous amount of rear steer and lift in the LR. Are the running super stiff springs in the right rear to counter the LR lift and LF raising?Are they tying the LF as well to limit the amount of travel? I didnt see alot of gap between the top of the tire and bottom of the fender area. Whatever they were doing it was fast.
12-30-2019, 11:16 AM
Jking24

Quote:

Originally Posted by Cranky

I was at 411 this weekend. I was noticing something curious to me in the supers and the crates. The very fast cars were carrying the LF down the straight away and putting it back down on landing in the corner. Now the LF was not a foot off the ground, it was only enough for the LF to stop turning midway down the straights. The cars that were doing this had a tremendous amount of rear steer and lift in the LR. Are the running super stiff springs in the right rear to counter the LR lift and LF raising?Are they tying the LF as well to limit the amount of travel? I didnt see alot of gap between the top of the tire and bottom of the fender area. Whatever they were doing it was fast.

Most current setups have the lf tethered and depending on rr adjustments will do this at times from my experience it's usually more influenced by track configuration than a particular adjustment. Basically it happens more at some tracks than others and they weren't probably doing anything different setup wise then they do at other tracks
12-30-2019, 11:34 AM
Punisher88

Most likely rubber down the straight and just shear traction.
12-31-2019, 08:18 AM
MasterSbilt_Racer

Quote:

Originally Posted by Cranky

I was at 411 this weekend. I was noticing something curious to me in the supers and the crates. The very fast cars were carrying the LF down the straight away and putting it back down on landing in the corner. Now the LF was not a foot off the ground, it was only enough for the LF to stop turning midway down the straights. The cars that were doing this had a tremendous amount of rear steer and lift in the LR. Are the running super stiff springs in the right rear to counter the LR lift and LF raising?Are they tying the LF as well to limit the amount of travel? I didnt see alot of gap between the top of the tire and bottom of the fender area. Whatever they were doing it was fast.

Most cars have the LF tethered. This is an old road racing trick. That unsprung mass becomes sprung mass, but supported by the other 3 wheels, once it lifts. This adds to rear wheel load for getting off the corner.

Roll angle is a product of cg height and lateral acceleration. With angle being constant, a softer rf will make the LF lift less.