Keeping LF from hiking up

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  • parocket
    Member
    • Feb 2010
    • 69

    #1

    Keeping LF from hiking up

    How can I keep my LF from lifting with out excessivly altering setup?

    06 blk rocket, lf 500, rf 350, rr 250, lr 250 drop at 13.25, pan bar 8.5

    Car runs well with setup but seems to try to dangle the LF. Its not coming off the ground but has excessive roll. Tried 350 in in Rf but handling suffered.
  • timmayb
    Senior Member
    • May 2007
    • 267

    #2
    Move weight forward, or set the 5th arm towards the rear if you aren't there already. We had a weight in our door bar and moved it to the LF and it helped drastically and improved handling.

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    • Gorum Racing
      Junior Member
      • Jul 2011
      • 2

      #3
      swap the lf spring with the rf spring i did that with mine and it help alot

      Comment

      • jedclampit
        Senior Member
        • Mar 2008
        • 613

        #4
        If the handling is where u want it let it be. If there is an area where you need to be better then an adjustment for that may be tied to getting the lf down.
        What are track conditions like when this excessive hike up is going on?
        Where are your bars set?
        Scale %'s w/driver?

        Comment

        • parocket
          Member
          • Feb 2010
          • 69

          #5
          I already moved my 5th arm back a hole.

          Been cutting back on drop to keep the car from running up track which helps drivability.

          Dry semi slick with medium banking. Hole are in std Rocket spot on chassis other than bottom right on chassis is in top hole. LR is 1/2 way donw birdcage.
          Rule about 108lbs bite, percents are 54.7 left and 54.8 rear.

          Car is running well running 1-8 on any given night if all things are going right with traffic but I assume this is not helping and the faster cars seem to keep their LF lower and the RR higher in the tail..more of that attack position.
          Always looking for forward bite at this track..grittiy, lack of clay track

          Comment

          • jedclampit
            Senior Member
            • Mar 2008
            • 613

            #6
            I see some counteracting adjustments going on... what type of engine combo..all steel/ all aluminum or combo? Seems odd for the rr lower to be uphill, with the given track conditions.

            I have some suggestions but I will hold back till I know your engine combo. By standard rocket spots... you mean where you scale?

            Comment

            • parocket
              Member
              • Feb 2010
              • 69

              #7
              combo engine (crate), the RR lower on chassis has been raised to help get the car in better. Its common for the feature to do the static tilt if track dries out and does not get gritty. The same amount fo roll seems to happen.

              Top rods in middle holes (not setup holes) and both bottoms 2 up.

              Comment

              • jedclampit
                Senior Member
                • Mar 2008
                • 613

                #8
                check you pm's.

                Comment

                • grasshopper
                  Member
                  • May 2011
                  • 34

                  #9
                  Try droping your J-Bar down a 1\2 inch it want let the car roll over as much. you will lose a little side bite but gain some foward bit.

                  Comment

                  • dualdj1
                    Senior Member
                    • Jun 2009
                    • 654

                    #10
                    going lower on panhard bars promotes roll. if you want less roll need to go up with one end of it. more rake generally more forward bite, less rake generally more side bite.

                    Comment

                    • Matt49
                      Senior Member
                      • Jun 2007
                      • 3123

                      #11
                      Originally posted by dualdj1 View Post
                      going lower on panhard bars promotes roll. if you want less roll need to go up with one end of it. more rake generally more forward bite, less rake generally more side bite.
                      Sorry but that is completely backwards.
                      In general , more rake in the j-bar promotes roll and will get the car up on the bars quicker.
                      In general, less rake provides less side bite and more forward bite.
                      In general, more rakes provides more side bite and less forward bite.

                      Comment

                      • jedclampit
                        Senior Member
                        • Mar 2008
                        • 613

                        #12
                        Originally posted by Matt49 View Post
                        Sorry but that is completely backwards.
                        In general , more rake in the j-bar promotes roll and will get the car up on the bars quicker.
                        In general, less rake provides less side bite and more forward bite.
                        In general, more rakes provides more side bite and less forward bite.
                        Correct, thats what I know to be true.

                        Comment

                        • grasshopper
                          Member
                          • May 2011
                          • 34

                          #13
                          I know if you lower the J-Bar on the frame the car want roll over as much you take away side bite but gain foward bite atleast thats my thinking. someone tell me if im wrong?

                          Comment

                          • dualdj1
                            Senior Member
                            • Jun 2009
                            • 654

                            #14
                            Sorry, allow me to clarify as I was talking panhard bars in general, not J-bars specifically, and bite was not the correct terminology. Thank you for pointing this out, been dealing with straight bar too much lately ><

                            More rake provides more downward force on whatever side of the pinion your bar is mounted. J-bar loads the right wheel which yes would provide more side bite. Less rake provides less force between RR and left side frame, keeping more load on LR spring/bars planting left wheel harder for more forward drive.

                            On short straight left bar, more rake loads LR more providing more forward bite, less rake more on the right wheel and more side bite.

                            So I should've said more rake = more downward force, what type of bite is dependent on the bar.

                            Roll however IS still effected by height, the lower the ends of the bar, the "easier" is it to roll, or less resistance to roll. If you need more resistance to roll, then you raise both ends to raise the moment center.
                            Last edited by dualdj1; 08-09-2011, 09:44 AM.

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