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Post by powercar82 on Sept 5, 2013 8:33:45 GMT -6
There seem to be conflicting ideas out there as to what the limits "should" be of setting the panhard bar rake.
Most places say a rule of thumb is 10% of the length should be maximum rake (example a 20" bar should never have more than 2" of rake center of heim to center of heim).
Jet Racing setup manual says never go more than a 10 degree angle (3.5" on a 20 degree bar) and the online GRT manual says start at 7" of rake for a baseline and put more angle in as the track slicks off.
Of course I realize the negative effects with “pogoing” and such that can happen with too much angle and I also realize that driver feel and the rest of the package dictate a lot when it comes to this. I am just curious what angles other sportmod/bmod drivers are running on the panhard or j-bars?
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Post by clbaker25x on Sept 5, 2013 10:27:42 GMT -6
One thing you see almost universally with bmods is that they are too tight on entry. Most folks are using panhard bar angle to put forward bite in their cars and their are much slower for it. We run our panhard bar flat and our car is one of the fastest cars around on slick tracks.
If you think your car is not too tight on entry then ask yourself how much rear brake do you have in your car and how much are you using that excessive rear brake to turn your car on entry?
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Post by dstrcto4x on Nov 17, 2013 15:46:47 GMT -6
i have been fighting tight issue from entry all the way through middle & when car finally rotates it digs hard off the corner, my panhard bar is mounted on the back of rearend just past the pumpkin to the right side, even with pinion with 6 inches of rake from center of heims to the left side frame. the bar is 27 inches long so if i was to use the 10% rule of thumb & drop it on frame side to approx. 3 inch split should this free the car up?? also when doing this should i unhook it & adjust heims to fit so i can keep the rearend were its at now or leave it hooked up to let it shove the rearend over to the right.
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Post by clbaker25x on Nov 18, 2013 10:17:23 GMT -6
Normally you don't want to let the rearend move for your static setting from left to right too much. So you will want to adjust your baseline setting so that the rearend is sitting where it is supposed to be in the car. Now if you are just adjusting the car to tighten the chassis as the night goes on then moving it a little to the left may not hurt too much as it should bring the right rear wheel in and make the car tighter.
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Post by clbaker25x on Nov 18, 2013 10:19:17 GMT -6
If your car is tight on entry through the middle, don't be afraid to flatten panhard bar completely. It will help the car free up quite a bit on entry.
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Post by dstrcto4x on Nov 18, 2013 19:29:36 GMT -6
thank you for the replies, i dropped it as far as i could on the frame side & its mounted on the rearend with no adjustments, final split ended up 2 3/4 inch on 27 inch bar. if i still have a tight problem i will have to find a way to bring rearend side up a little more ?? next time i will get to try it will be on the 29th and it will be more of a dryslick track where is to my tight cond. was on a tacky wet, so the slicker the track gets the higher split you want is this correct? if the car ends up loose in how far up should i take it maybe 1 inch at a time? thank you for the help & sorry for so many questions as this is all new to me coming from leaf spring street stock!
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Post by clbaker25x on Nov 19, 2013 9:15:19 GMT -6
I know it sounds crazy but we never adjust our panhard bar. I look at my rear panhard bar as simply setting my rear roll center. Once it is set to give me a balanced car I don't like to move it. There are too many other adjustments that I use to change the car for the slick conditions. What are your springs and weight percentages? We soften our RF spring to tighten the car as the track slickens off (it adds side bite to the car and allows the car to turn through the middle much better). We run a hundred pounds of spring split in the front on tacky (450 LF/550 RF) and then drop our RF spring to match the track as it slicks off. We will go either 400, 350 or 300 depending on how slick it gets. We run same QA1 50 series shock on the RF all the time 3 compression and 7 rebound.  We will also adjust our right side bar down to tighten entry and help with drive as the track gets slicker. |
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Post by dstrcto4x on Nov 22, 2013 17:24:29 GMT -6
Wow i have never tried the springs that soft in front, right now my springs are 600 l.f 650 r.f and 200 l.r 175 r.r. with me in car my % are left 53.9, rear 55, cross 51, with 140 lbs. Bite. Left rear bar is @ 18°, right rear bar is 5°, scaled with 3" stagger in back and 1/2" in front. Do you see any major changes needed other than me already dropping panhard bar? Thank you for the help!!
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Post by chris74az on Nov 25, 2013 8:47:10 GMT -6
I tried that much bite and almost took the wall down(heavy track) had to drop it to 50lbs starting point! That much bite might be good for the main (real slick). Also I found that you only feel the jbar dig in the center of the turn when it rotates! To much angle and the right rear will dig to much(upon rotation) and sling the front end up!
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Post by clbaker25x on Nov 25, 2013 9:06:39 GMT -6
Here is a link to our car racing on a heavy track. This is with 300 pounds of bite and the rest of our normal setup.
Just gotta get your car balanced right if you want to have that much forward drive in your car. I really believe it gives you a distinct advantage over other cars. Especially in the A feature when the track slicks off.
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Post by Toywagon on Nov 25, 2013 20:30:10 GMT -6
Same here as Dbaker. Rarely move the J bar. I think the last time we moved it we went to a heavy clay track with tight high banked corners, and I raised both ends of the bar up an inch due to the car just being over on the right side too heavy.
Jim
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Post by flipflopoo1oo on Feb 25, 2014 13:26:00 GMT -6
Neither bar is a fix all and should be placed to do the job at hand and not adjusted for other reasons! Low cross during rollover and spring movement along with shock packages can lock you straight to the wall! 53-54 cross seams to put most cars at ease depending on the rest of the factors! I hate short springs that coil bind during roll over! If the right front drops first it should raise left rear putting instant steer into affect just by taking your foot off the throttle while at the same time transferring weight from rf to lf to rr to plant you going in without touching a brake! If car does this, bar location should not be upsetting when throttle is applied by extreme angles. So many car faults are propped up by short bars! Every car is different in design or ride height that bar length and angle has to be assessed as it's used!
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