Mavrick

In nascar, what exactling are they adjusting when they adjust these two, and what ecactly do they do to help? Also, would it be possible to set up our cars so that it was that easy to adjust?

Jukka

I am not sure what you are talking about but let me remind you that in Nascar they mostly turn to left. In street driving and other than nascar race tracks they turn also right
To make F-body adjustable? Atleast there are adjustable shocks.

Dewey316

wedge is for adjusting corner weights, you can do this with a weight jack system from ground-control.

trackbar adjustments in nascar are adjusting the way the panhard sits, it is basicly a verticly adjustable mount for it. you're on your own for fabbing that up.

Mavrick

Yea i know that they only go in circles. I was just curious what it is exactly that they are adjusting during the race.

Mavrick

ok, thanks Dewey. I always wondered what it was they were adjusting

ronterry

I know with the trackbar they will adjust the left side height before the race usually during practice, and during the race they can adjust the right side height via a screw. The trackbar will help in under/oversteer, like said above this adjustment will favor right or a left turn. This adjustment helps the rear go into the turn easier.
The wedge is another name for a spring jack; again this will favor a right or left turn by moving weight to the RF/LR or LF/RR. This setting helps in loading the tires for more or less weight, again helping the car with an under/oversteer.

On the two road courses they run, both of these settings are normally neutral.

These setting along with pulling spring rubbers and messing with tire pressures are the only real setting that can be done during a race. There is literally hundreds of setting to mess with before any race. Shocks, springs, camber, caster, toe, swaybar sizes, aero, etc - etc - etc - etc....All in an effort to make that sucker turn better than the competition.

Ron

AGood2.8

Track bar (or J-bar as its really known. Trackbar is just announcer and fan lingo) adjusts the rear roll center on the car. This is set lower at the pinion initially for push/ and higher at the pinion for loose. Cars will generally loosen as the race goes- so generally more push is set into the pinion height mount. (They use computer program graphics to set roll centers and roll axis! this can't be designed by eye.)

Then- The body mount side of the bar is set to a position that is balanced for the car at that moment (with fresh tires, full fuel cell, low heat on shock valves, etc.. many factors that change throughout the race.)
As the race progesses, the track bar is lowered on the bodyside mount (not the axleside) via a screwjack assembly. This lowers the rake of the roll axis and causes the rear to bite more. (that really means it balances the rear grip back up to even with the front under heat and weight changes)

Edit: the same can be done through wedge setting (done in days of old) however, adjusting too much wedge will cause excessive heatr buildup in some tires and not others causing more wear and loss of grip (meaning more piitstops) The track bar adjustment will keep temps more predictable.