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Author Topic:   4 Bar/4 Bar J-Bar or Straight Bar? Heights?
socaldirtmod
Dirt Roller

Total posts: 23
posted November 30, 2005 10:41 PM  
Run 4 Bar on right and left, just wondering what kind of J-bar heights anyone has run (ground to Pinion and Chassis side of J-bar)
Anyone experiment with a straight/short bar on the drivers side of the pinion with the 4 bar on both sides? what kind of heights? running under IMCA so either has to be 19" long. I have run between 2-4 inches of difference with a J-bar but haven't gotten the RR to stick as much as i would like? Not enough angle? Thinking of running a short/straight bar with some extreme angles? what have you all run?

mod46
Dirt Roller

Total posts: 5
posted December 01, 2005 03:40 AM  
We ran a J-bar and had the same trouble that you stated. Not enough side bite / or body roll. We use a 19 inch panhard bar on the left side of the pinion now and love it. We have to change our springs in the rear to keep the left front on the ground and gain forward bite.
Now I have a question: When I pickup the trottle my car turns left hard. it still picks the left front up about 4-6 inches off the corner. It will carry the left front all the way down the straight away. I need to settle this down a little so the car does not want to turn quite as hard. What would you do? We run a 1/2 mile track.


nwarkracefan
Dirt Roller

Total posts: 25
posted December 01, 2005 04:23 PM  
we have had good luck running a straight bar to the left side of the pinion. To meet the length requirement we simply turned the frame mount clamp for the panhard bar around so that the mounting tab faces out the left side of the car, and run the panhard bar out to it. My wording my be hard to decipher, and I don't have a pic to show what I'm talking about, but maybe someone can understand my point and better clarify.

This allows us to run "normal" panhard bar angles, and most of our drivers seem to like it better than the j-bar.

GRTWallbanger
Dirt Freak

Total posts: 201
posted December 02, 2005 11:34 AM  
Mod46?
When you say your car goes left hard when you get on the gas?Do yo mean it goes toward the infield?If this is the case it sounds like it is driving off the RR when you get on the gas??
Just a thought?

CLBaker25
Dirt Freak

Total posts: 214
posted December 02, 2005 11:41 AM  
Isn't the car turning on the gas and under roll too much rear steer?

socaldirtmod
Dirt Roller

Total posts: 23
posted December 02, 2005 01:42 PM  
Kind of what i was thinking, lower the left side bars take some rear steer out, or like you mentioned, stiffer RR spring? were are your RR bars?

I guess not alot of people with the 4-bar/4-bar for the j-bar/straight-bar heights huhn??? anyone???

[This message has been edited by socaldirtmod (edited December 02, 2005).]

GRTWallbanger
Dirt Freak

Total posts: 201
posted December 02, 2005 04:05 PM  
I would say average starting point for J-Bar or straight bar is pinion height and about 4inchs higher on frame?They say straight bar dones not like much angle(esp. if it is short)

dirtzone
Dirt Maniac

Total posts: 104
posted December 03, 2005 06:16 AM  
GRT, you're right. I ran a 4-4 with both shorty and j bar. Actually liked the j bar better. Not alot of angle required for the straight. J bar has a slower arc, so more static angle helps the initial side bite. That's assuming everything else is satisfactory with the setup, of course.

showtime13
Dirt Full Roller

Total posts: 66
posted December 03, 2005 10:29 AM  
http://www.afcoracing.com/tech_pages/panhard.shtml#height

Try this maybe this will help you understand

dirtrace54
Dirt Freak

Total posts: 218
posted December 03, 2005 10:54 PM  
SOCIALDIRTMOD, 4 inch defference on a jbar doesnt sound like enough if your having probs getting the car to get sidebite. i would go as high as 6 or mabye 7. The straight bar does use less angle. Either way, if you have a standard four/eight(if has holes on both sides) hole bracket on your pinion. id make sure the bar is in the lowest hole when using the jbar and the next to bottom when using the straight bar

MOD46, i would drop angle in the lower left bar. by doing this you will increase LR foward drive on throttle and decrease roll steer which both with help with you probs. dont know what its current angle is, but this is just a suggestion.

i hope these help. just throwin some ideas around

mod46
Dirt Roller

Total posts: 5
posted December 05, 2005 03:08 AM  
Thank you for all your suggestions. This is where I am at right now.
RR upper 15 degrees/ lower 7 degrees
LR upper 24 degrees/ lower 15 degrees
Pinion angle 7 degrees
Pull bar angle 17 degrees
5 inches angle to panhard bar
One more question? What if I were to move the LR upper bar close to the center of the rearend on the bird cage. What would this do?

dirtrace54
Dirt Freak

Total posts: 218
posted December 05, 2005 02:08 PM  
it would index the cage faster on throttle

and just from lookin at bar angles....the LR lower should only be a few degrees higher than the right lower.....i would say try to get 4 or 5 degrees on the RR lower and hit 7 or 8 on the LR lower.....just a thought

socaldirtmod
Dirt Roller

Total posts: 23
posted December 06, 2005 10:27 PM  
Thanks for the advice guys, i will try more angle in either bar i run, not enough from what i gather!

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