RF Setup

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  • 7uptruckracer
    Senior Member
    • May 2009
    • 1336

    #1

    RF Setup

    I was out of the game most of last year and have gotten behind. I focused on my asphalt stuff. What’s the current trend of RF. Was running a 225 with a red Penske cone bump but struggled for mid corner sidebite and drive off. Lowering RRL bar didn’t help. Lowering Jbar on Pinion didn’t help. Raising RR spring rate didn’t help and taking 2-4 turns out RR didn’t help, taking LF chain tie down didn’t help. I’m thinking something with the RF just didn’t agree but can’t figure out if it was just on the RF to long and couldn’t get the correct transfer to the rear or what it is. I want to try a RF stack but I have no clue what they run these days or how much they engage them. Do you still want the same dynamic load and do you want the same engagement window as I had with the bump?
  • grt74
    Senior Member
    • Jul 2009
    • 1380

    #2
    most are working in a 1 to 1 1/2 inch window on the rf now, don't forget to think about the rr, people are working really hard there too
    the problem is,most of this fine fine tuning is very track dependent, so ,and i can not stress this enough,KEEP GOOD NOTES, that is going to win races
    load at certain numbers are everything these days, no one cares about ride heights anymore (of coarse this is after the car is scaled a checked for alignment) only to pass tech heights at the beginning on the race, the only reason we run all this crazy chit is to pass tech, then its all about dynamic load and tire patch, start thinking that way and i think you'll see a whole different picture
    just trying to get you thinking here, not being a wise guy here at all
    kind of car will help
    make sure your checking your rf load numbers everyweek on a smasher, if your not, depending on your bumps, i think you'll find out things change from week to week
    Last edited by grt74; 12-28-2019, 05:36 PM.

    Comment

    • 7uptruckracer
      Senior Member
      • May 2009
      • 1336

      #3
      I purposely left out the chassis type, I have all my static and dynamic load numbers. Car is awesome early in the night. Once it blows off though the car doesn’t respond to any changes. You can do all the stuff mentioned and it acts the same way. I don’t know if I don’t have enough RF load or I’m tied down to much on the RF I’m not sure how you tell. It’s just like the RR won’t catch the car and by mid turn it’s over rotated and you either can’t gas it up without spinning or it does straight the car when you gas it but you are cooking the RR if that makes sense, now with ALL that being said I have yet to rule out the driver as the problem

      Originally posted by grt74 View Post
      most are working in a 1 to 1 1/2 inch window on the rf now, don't forget to think about the rr, people are working really hard there too
      the problem is,most of this fine fine tuning is very track dependent, so ,and i can not stress this enough,KEEP GOOD NOTES, that is going to win races
      load at certain numbers are everything these days, no one cares about ride heights anymore (of coarse this is after the car is scaled a checked for alignment) only to pass tech heights at the beginning on the race, the only reason we run all this crazy chit is to pass tech, then its all about dynamic load and tire patch, start thinking that way and i think you'll see a whole different picture
      just trying to get you thinking here, not being a wise guy here at all
      kind of car will help
      make sure your checking your rf load numbers everyweek on a smasher, if your not, depending on your bumps, i think you'll find out things change from week to week

      Comment

      • drgracer392
        Member
        • Jun 2014
        • 37

        #4
        RF load or tied down too much would be my guess.... I gonna say if it turns well with the soft RF but don't have drive its a RF load issue say its too soft.

        Comment

        • 7uptruckracer
          Senior Member
          • May 2009
          • 1336

          #5
          Maybe this will load it’s a load photo on RF 225 with a Blue like rubber and 225 without blue line rubber

          Originally posted by drgracer392 View Post
          RF load or tied down too much would be my guess.... I gonna say if it turns well with the soft RF but don't have drive its a RF load issue say its too soft.
          Attached Files

          Comment

          • fastford
            Senior Member
            • Dec 2008
            • 4059

            #6
            the problem with drive off on a soft rt frt and bump or two stage either one is usually in the left rear , it took me a while to get my head wrapped around it , but in the end , left rear bar angle and drop was where most of my problems were fixed , dynamic rear steer is critical,,,,,JMO,,,,

            Comment

            • ZERO25
              Senior Member
              • Aug 2018
              • 5240

              #7
              Im assuming you mean loose off the gas. I would try more lf spring and less lr bite. I know a guy who wins regularly in a bwrc, his lr bite is wayyyyyy low!

              Comment

              • MasterSbilt_Racer
                Senior Member
                • May 2007
                • 14324

                #8
                Originally posted by fastford View Post
                the problem with drive off on a soft rt frt and bump or two stage either one is usually in the left rear , it took me a while to get my head wrapped around it , but in the end , left rear bar angle and drop was where most of my problems were fixed , dynamic rear steer is critical,,,,,JMO,,,,
                I agree. But I've found vastly different numbers work at different type tracks.
                Modern Day Spec Wedge Racing

                Comment

                • MachineMasters
                  Member
                  • Oct 2010
                  • 74

                  #9
                  To me it sounds like the RF is locked down too hard with rebound.. I would open up the adjuster a few clicks and see if it doesn't get better.

                  Keep in mind it will tighten the car through the center..so if the root cause of your issue now is the car being overly tight, taking RF rebound out would likely make the problem worse.

                  Comment

                  • 7uptruckracer
                    Senior Member
                    • May 2009
                    • 1336

                    #10
                    So I’ve been doing some digging. My 3” number is around 1400# 3.5” is about 1600# 4” about 1800#
                    4.5” is about 2200# and 4.75 is 2700#. Now should I be lowering rate as the track slicks off to keep posture or should I be adding shim to ramp it up so it can push back on the LR? What would you think of you saw these numbers? This is on a 225 with a rubber and a red Penske bump but I’m not sure I like the Penske bump. I really think a stack might be better. Currently only going to one track with this car

                    Comment

                    • MasterSbilt_Racer
                      Senior Member
                      • May 2007
                      • 14324

                      #11
                      Even with my moderized Gen X, I can't travel that far. That's my first observation.

                      In a perfect world, your travel wouldn't change. Nor would the loading bias (front to rear) with lateral weight transfer, if your car was balanced correctly.
                      Last edited by MasterSbilt_Racer; 01-03-2020, 08:25 PM.
                      Modern Day Spec Wedge Racing

                      Comment

                      • JustAddDirt
                        Senior Member
                        • May 2007
                        • 1893

                        #12
                        Sounds like an xr1 with those travel Numbers
                        I think there should be lifeguards in the genepool.

                        Comment

                        • 7uptruckracer
                          Senior Member
                          • May 2009
                          • 1336

                          #13
                          Shocks installed height is 18.25 pin to pin and this number is down to 13.5. On a Ohlins LMP they said can go to 12.8. It’s a lazer they said it can travel 5” and they said to make sure it stops there, which would be be a 13.25 center to center. I need to take it out to double check but I know we do travel it to the 13.5 when the tracks hammer down this is a 358 steel head wet sump division

                          Originally posted by MasterSbilt_Racer View Post
                          Even with my moderized Gen X, I can't travel that far. That's my first observation.

                          In a perfect world, your travel wouldn't change. Nor would the loading bias (front to rear) with lateral weight transfer, if your car was balanced correctly.

                          Comment

                          • Mr.Kennedy777
                            Senior Member
                            • Aug 2016
                            • 212

                            #14
                            One thing that could be affecting your side bite mid turn is also your drop load. Too much drop load in LR can hurt your side bite I've found. Steer and thrust play a role too but I'd be looking at the drop load numbers.

                            Comment

                            • 7uptruckracer
                              Senior Member
                              • May 2009
                              • 1336

                              #15
                              200# extension load

                              Originally posted by Mr.Kennedy777 View Post
                              One thing that could be affecting your side bite mid turn is also your drop load. Too much drop load in LR can hurt your side bite I've found. Steer and thrust play a role too but I'd be looking at the drop load numbers.

                              Comment

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