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Author Topic:   long rear panhard bar for dummy!!!
wingnut
Dirt Maniac

Total posts: 134
posted October 15, 2004 04:50 PM  
This dummy can not get it straight in his head!!!
Long bar on the back of the housing, 4 bolt clamp on mount tack welded on the right side tube. left side frame mount with 5 hole bracket.

If I start with the bar in the middle hole for tacky/ wet track , do I need to raise it or lower it for dry feature track?

Raising the bar on the left raises R/c , which frees the car up, lowering the bar lowers r/c and lets the chassis "getover" r/c and help stick rr on dry track which will help turn car through the corner?

Guys I know that you have gone over this a bunch and i have gone back throught the posts for two days, thought i had it figured out, then today I got two different answers from guys that have forget more then i will ever get to learn about racing.Somehow i can't seem to get it through my head@ thank you

FASTLAP
Dirt Maniac

Total posts: 171
posted October 15, 2004 05:12 PM  
The more you raise the bar on the frame, the more sidebite you're putting in the RR.
Start out lower for heavy, then work your way up the frame the slicker it gets. More angle = more sidebite. Hope this helps.

FlyNLoIMCA17
Dirt Forum Champ
Total posts: 753
posted October 15, 2004 05:29 PM  
yep thats it!! Raise it as the track drys out.

37mod
Dirt Full Roller

Total posts: 36
posted October 15, 2004 06:03 PM  
I don't believe that is exactly right. If you lower it on the left side frame it will make the car want to roll more if you raise it, it will make the car want to roll less. But also the more angle the more the car will want to lift the left side due to the rear end moving farther to the left when it gets into the corner.

2nd2none
Dirt Forum Champ
Total posts: 755
posted October 15, 2004 09:39 PM  
quote:
Originally posted by 37mod:
I don't believe that is exactly right. If you lower it on the left side frame it will make the car want to roll more if you raise it, it will make the car want to roll less. But also the more angle the more the car will want to lift the left side due to the rear end moving farther to the left when it gets into the corner.

If it rolls less by increasing angle, how can it "lift the left side due to the rear end moving farther to the left when it gets into the corner". If the rear rolls less with more angle how can the rearend be pulled farther to the left?

Raising the WHOLE bar (both ends) will raise the rollcenter which loosens the car.

Lowering both ends lowers rollcenter....tightens car.

wingnut
Dirt Maniac

Total posts: 134
posted October 15, 2004 09:53 PM  
since our mount on the rearend is a fixed point and does not raise or lower without cutting the tack weld { an even longer story why that was done}, what effect our we having by only moving the left side up or down ? thank you again for your help.

FASTLAP
Dirt Maniac

Total posts: 171
posted October 16, 2004 05:59 AM  
quote:
Originally posted by 2nd2none:
Raising the WHOLE bar (both ends) will raise the rollcenter which loosens the car.

Lowering both ends lowers rollcenter....tightens car.


Agreed! There's a big difference between moving both ends or just one.
wingnut, raising or lowering your leftside mount affects your sidebite as stated before.

KK17
Dirt Freak

Total posts: 229
posted October 16, 2004 01:10 PM  
go to AFCO's website and click on tech articles..they have a good article on panhard bars..

dirtywrench13
Dirt Freak

Total posts: 324
posted October 17, 2004 06:54 AM  
IT DOESN'T ROLL MORE, IT ROLLS FASTER. I'D START LOW ON THE LEFT ON A HEAVY TRACK, THEN RAISE IT FOR A DRY TRACK.
SPRINGS PLAY AS MUCH A ROLE IN THIS AS THE BAR ANGLE DOES.

GRTWallbanger
Dirt Maniac

Total posts: 196
posted October 19, 2004 04:08 PM  
SO, If you want the car to roll over on the rr more you would put more ange in it?
By raising it on the frame?

diggen
Dirt Roller

Total posts: 17
posted October 31, 2004 09:23 PM  
ok think of it like this, your panhard is like a kickstand on a bike if you put your k-stand down at he angle it is normally at, which is alot of angle it holds the bike up.... ok now reach down and pull it up at the bottom (flatting it out) what happens now the **** thing falls over.,. panhard FLAT win dry!!!!

Ego Racing
Dirt Forum Champ
Total posts: 724
posted November 01, 2004 08:29 AM  
One thing to remember is that a long bar plants the right tire more than a J bar. The downforce of the J bar is induced where the bar ties to the rear housing.When the track goes dry you want to try to add cross to the car. When books say lower the bar they mean on the rear mount to add more angle to the bar which quickens the loading of the tire, just like adding angle to the top bars of a 4 link make it come in quicker or adding angle to the top link make the car tighter during acceleration.
More angle more and sooner reaction.
When the track goes dry we change our cars to a short bar because it loads the left rear more, this allows us to start with less LR bite and let the bar induce the weight when the chassis rolls over. When our car goes up on the J bar the tires load almost evenly and we run 100-175lbs of bite depending on the track. When we go to the short bar we adjust to 30-50lbs of bite and when up on the bar the car is at 190-225lbs of bite.
Measure your shock travel at the track after a race. Make solid links and remove the springs and put the links inplace to jcak the car up like it is on the track, now adjust the track bar and see what happens to the rear tire weights. You can also try different bar lengths.

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