Car Does Bunny Hop @ The Track

Racers Hangout

  1. dvw

    dvw Well-Known Member

    Messages:
    4,554
    Likes Received:
    6275
    Joined:
    Feb 16, 2010
    Location:
    waterford mi
    Local Time:
    8:19 AM
     
  2. 1967coronet440

    1967coronet440 Well-Known Member

    Messages:
    6,820
    Likes Received:
    9441
    Joined:
    Oct 26, 2016
    Location:
    Indiana
    Local Time:
    7:19 AM
    Try this Doug

     
  3. slimt

    slimt FBBO Gold Member FBBO Gold Member

    Messages:
    1,900
    Likes Received:
    1899
    Joined:
    Apr 17, 2017
    Location:
    Alberta
    Local Time:
    6:19 AM
    Alot of drop on take off. Sure looks like it needs more stability.
     
  4. moparcrazy

    moparcrazy Well-Known Member

    Messages:
    2,162
    Likes Received:
    1628
    Joined:
    Dec 27, 2009
    Location:
    california
    Local Time:
    7:19 AM
    500 ci 440, 15.5 compression, Max wedge Victor Heads Fully ported, roller cam .720 & 1.6 Harland Sharps Rocks I bought from you (Bo) :thumbsup: Indy 4500 intake, Gen 3 Dominator 1050 dynod @ 791-797 HP
     
    • Like Like x 3
    • Thanks! Thanks! x 1
    • Lefty71

      Lefty71 FBBO Gold Member FBBO Gold Member

      Messages:
      1,429
      Likes Received:
      1526
      Joined:
      Mar 8, 2018
      Location:
      Ohio
      Local Time:
      8:19 AM
      I learned that...... turned my rev limiter back down, and got right back to the big 10-0....
      :poke:
       
    • Lefty71

      Lefty71 FBBO Gold Member FBBO Gold Member

      Messages:
      1,429
      Likes Received:
      1526
      Joined:
      Mar 8, 2018
      Location:
      Ohio
      Local Time:
      8:19 AM
      Wow-wee that sounds swwweet, like maybe you shoulda got your racing license first lol. I got to the 9's with a lot less motor than that, although maybe a little lighter car, and maybe taller gear??? You know it's harder to slow them down than it is to build them up. :steering:
       
      • Agree Agree x 1
      • dvw

        dvw Well-Known Member

        Messages:
        4,554
        Likes Received:
        6275
        Joined:
        Feb 16, 2010
        Location:
        waterford mi
        Local Time:
        8:19 AM
        I saw the video. The front and rear rebound are WAY to loose. 5"-6" of travel should be plenty once the shocks get the rear housing speed under control. The shock only controls the speed of housing travel. With leafs the instant center is high and short. The car has a fair amount of power. With these parameters the reality is that it's going to throw the housing out of the car pretty hard. Tight rebound will slow the housing enough that it won't crush the tire and unload it. The front is coming up to quick as well. Hopefully the front shocks are adjustable.
        Doug
         
        • Like Like x 2
        • moparcrazy

          moparcrazy Well-Known Member

          Messages:
          2,162
          Likes Received:
          1628
          Joined:
          Dec 27, 2009
          Location:
          california
          Local Time:
          7:19 AM
          Thank you Doug, the front shocks are coil overs set on the softest setting so ill start with one click and go from there, rears are set at 3 clicks and Caltracks recommended 6-7 clicks + on rebound, planning on starting at 5 clicks and adjusting from there, track is out tomorrow due to weather so maybe the weekend ill take more video and post the results, thanks again for your knowledgeable input, Jay.
           
          • Like Like x 1
          • malex

            malex FBBO Gold Member FBBO Gold Member

            Messages:
            1,722
            Likes Received:
            2164
            Joined:
            Aug 10, 2013
            Location:
            Canada
            Local Time:
            7:19 AM
            Seeing your problem took me back to last season, I had all the same shit and starred in videos just like you posted. Before I got things sorted out I lost a nice aluminum driveshaft, a yoke, u-joint, a bent calvert shock bracket and curled up my spring perches.
            Doug has you on the right track though, he'll get you there.

            For what it's worth, on my car, where I ended up to get it to hook most of the time was:
            3200 RPM launch. Front double adjustable shocks set on 7, Rear double adjustable shocks set on full tight rebound and 14 compression. The extra front shock rebound helped settle things down lots.
            What my car needed was the rear QA1 shocks re-valved stiffer to keep from throwing the diff out so hard. I was able to get some 1.38's with this set up, but if I turned up the launch it would go stupid right away. If your perches aren't boxed you had better check them real good with that power cause they will flatten out if not already.
            Good luck!

            Launch Problems


            1.38 60’s - shock rebound added.
            4161BE1A-D51B-4D51-8272-871BE6B4321D.jpeg
             
            Last edited: Mar 24, 2019
            • Like Like x 3
            • moparcrazy

              moparcrazy Well-Known Member

              Messages:
              2,162
              Likes Received:
              1628
              Joined:
              Dec 27, 2009
              Location:
              california
              Local Time:
              7:19 AM
              malex thank you for the video & your input, 1.38's sure look nice compared to my 1.45 60'ft currently I'm running Calvert shocks in the rear with single adjustable QA1 coil overs in the front, launching @ 3000RPM, eventually would like to launch @ 3500rpm ? also thank you for the heads up regarding the perches, definitely going to take a look at them.
               
            • malex

              malex FBBO Gold Member FBBO Gold Member

              Messages:
              1,722
              Likes Received:
              2164
              Joined:
              Aug 10, 2013
              Location:
              Canada
              Local Time:
              7:19 AM
              —-
              YW. Yes when I was doing leap frog it was also 1.45 60’s.
              You will get a handle on it, it’s going to take shock tuning though. IMO you have crossed that line with that big power and you need to control your suspension with good good shocks now. I spent lots of time with Calvert working on my problem too, they seem reluctant to say to tighten the shocks up. Seems that on our b bodies though it needs to be done when making lots of power. Lots of anti-squat in these cars.
              Hopefully your perches haven’t started to bend yet. It’s easy to reinforce them now but once they start to curl then you will have a job ahead. Imagine that pinion angle changing as it rolls back during launch..
              I also run about the same engine combo as you except less compression. I’m 12.8.

              The right side curled
              More than the left.
              C77E998A-D07E-48BF-B9F5-B0170A551712.jpeg
               
              • Like Like x 3
              • Cranky

                Cranky Banned Staff Member FBBO Gold Member

                Messages:
                19,600
                Likes Received:
                15498
                Joined:
                Dec 4, 2009
                Location:
                Pasa-getdown-dena Texas
                Local Time:
                7:19 AM
                Man, been a long time since seeing a car do that lol. And if CT is recommending you put in 6-7 in the rears, I could rather go with that and then work down if it's too much. To me, that's being on the safe side of the pie and rather not break stuff stuff because things are still too loose.



                Yup....reinforce them before hand is the best policy!! Years ago a buddy and I chased our butts with a set of CT's on a nose heavy Challenger and CT couldn't much help but I did convince my buddy to reinforce the spring mounts before they got bent. Anyways, we ended up throwing ladder bars on the thing and it responded very well with a basic setup and then went on to running 9.30's with a small shot of the funny gas.
                 
                • Like Like x 1
                • Agree Agree x 1
                • malex

                  malex FBBO Gold Member FBBO Gold Member

                  Messages:
                  1,722
                  Likes Received:
                  2164
                  Joined:
                  Aug 10, 2013
                  Location:
                  Canada
                  Local Time:
                  7:19 AM
                  —-
                  One fast guy told me: Yup, we’ve all been there. He was referring to this exact problem and nope it wasn’t Cranky.
                  Hoping to have similar results with my new ladder bars on the 64 as Cranky did and my Calverts found a new home too.

                  3323D9C0-7A84-4A0F-B3FC-A9BC14501CD9.jpeg
                  0382FAA5-C455-4243-9D02-86A8A009A702.jpeg
                   
                  • Like Like x 2
                  • Mike Gaines

                    Mike Gaines Well-Known Member

                    Messages:
                    1,943
                    Likes Received:
                    3803
                    Joined:
                    Apr 17, 2014
                    Location:
                    Ahwahnee, (Fresno) California
                    Local Time:
                    5:19 AM
                    To repeat my earlier postings:
                    Every thing below was with my Cal Trac 90/10 front shocks.
                    My typical 60' was 1.40 to 1.42 and car went consistent 10.16-10.17. Cal Trac single adj Shocks set on 1 as per cal trac recommendation for trans brake car.
                    I took 92lbs out of the car (from the rear axle back) with glass deck lid and other steel stuff out of the trunk.
                    Pulled up to the line with same setup as my 1.40 to 1.42 60' setup....3600 chip & shocks set on 1 and it just blew the tires off the car.
                    Talked Cal Trac, they said to put the shocks on 3.
                    I put the Cal Trac single adj shocks on 7.
                    Pulled up to the line and clicked of a 1.39 60' and went 10.06.
                    Next run I clicked of a 1.37 60' and went 10.04.
                    The suspension liked the stiffer extension and allowed the car to launch.
                    The better 60' and the 92 lb weight savings took the car from 10.16 to 10.04.
                    Made me a happy man.
                     
                    Last edited: Mar 24, 2019
                    • Like Like x 2
                    • moparcrazy

                      moparcrazy Well-Known Member

                      Messages:
                      2,162
                      Likes Received:
                      1628
                      Joined:
                      Dec 27, 2009
                      Location:
                      california
                      Local Time:
                      7:19 AM
                      Mike as always thank you for your input, where does the car weight in now?
                       
                    • Mike Gaines

                      Mike Gaines Well-Known Member

                      Messages:
                      1,943
                      Likes Received:
                      3803
                      Joined:
                      Apr 17, 2014
                      Location:
                      Ahwahnee, (Fresno) California
                      Local Time:
                      5:19 AM
                      On the start line with 4 gal gas and me the car weighs 3508lbs.
                       
                      • Thanks! Thanks! x 1
                      1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
                        By continuing to use this site, you are consenting to our use of cookies.