Dr Diff Offest Kit With Oval Track Springs

Suspension, Steering and Chassis

  1. 1975abody

    1975abody Well-Known Member

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    just installed BBP axles,Dr Diff offset kit along with zero arch oval track springs. When I set the car down off of the jack stands the forward portion of the springs went into reverse arch, and it appears that the springs moved the axle toward the rear of the car more than the 1/2" that I was anticipating.

    There is only about 1/16" of clearance between the differential and gas tank also.

    The reverse arch is looks worse than the pictures show.

    Are all the things I am seeing normal with this combination of parts ?

    Does anyone have wheel hop problems with the oval track springs?

    60F65414-CC9C-42DA-A23E-5F6347F70DD5.jpeg

    A51761B8-78BD-4A25-9196-1E9AE7507D3F.jpeg
     
  2. 72bluNblu

    72bluNblu FABO Gold Member FABO Gold Member

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    That’s not normal. Something totally screwed up with the front of that spring pack. The reverse arch is wrong, and the axle is kicked too far back (probably partially because of the arch).

    I think Mopar performance has really dropped the ball lately with the manufacturing on those springs. They used to be a good option, but it seems like there’s been a lot of people having issues with them lately.
     
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    • 1975abody

      1975abody Well-Known Member

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    • thesiren74

      thesiren74 Well-Known Member

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      Super stock.
       
    • 1975abody

      1975abody Well-Known Member

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      Any suggestions for 120 lb/inch rate springs ?
       
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

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      I’m sure the DoctorDiff hangers are fine. The oval tracks are supposed to move the axle back, but it’s only supposed to be a 1/2”.

      All the other spring choices for handling cars are more expensive. Hotchkis springs are pricey, and they’ve had some ride height issues as well. Bergman Autocraft sells a custom set of Eaton springs with a 130 lb/in rate that Peter Bergman spec’d out. They’d be my first choice, they’re high quality springs. But again, expensive.

      It’s a damn shame AFCO stopped making the 120 lb/in Chrysler springs. Pretty sure that was a licensing issue because MP started back up with the oval tracks at the same time AFCO cut production on the 120 lb/in version of their springs. The AFCO’s are great, I’ve bought a set of the oval tracks recently too and they don’t compare. I may be in the same boat, I haven’t installed the oval tracks on my Dart yet.

      Drag race only. They suck for anything else.
       
    • thesiren74

      thesiren74 Well-Known Member

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      Probably for autocross but for drag and street i haven't had any problems.
       
    • 1975abody

      1975abody Well-Known Member

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      Interested to hear how yours work out.
       
    • 72bluNblu

      72bluNblu FABO Gold Member FABO Gold Member

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      They're terrible on the street. I’ve run them, they’re awful compared to a 120 or 130 lb/in spring with a good set of shocks. Yes, they’re great if you need to hook at the track, but that’s all.

      A lot of people make excuses for these cars not riding or handling well because “it’s an old car”. Well, it’s BS. Set them up right and they can ride and handle great.

      I’m skeptical. They don’t look bad enough to justify sending them back on sight alone, but I’m not sure they’ll be any better than yours.
       
    • thesiren74

      thesiren74 Well-Known Member

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      I would never expect them to ride like a new challenger but if i wanted that I'd be driving a new challenger.
       
    • 1975abody

      1975abody Well-Known Member

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      I bought mine back in September for $88 per spring.
      I painted them and pressed to front bushing out so I guess they are paper weights now.

      Does anyone have a picture of their car with ESPO 1" under springs ?

      Too bad most companies don't give a rate for their springs.
       
    • dirty white boy

      dirty white boy 47 yr old Juvenal delinquent

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      afco probably quit making them when most circle tracks banned mopar leaf on any car not a mopar from stock class threw late model, them spring were really popular in jig built late model class's in the late 80s, by mid 90s composite mono leafs were the hot ticket for circle track!
       
    • 1975abody

      1975abody Well-Known Member

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      Anyone have experience with these ?

      Not sure if this picture is of the actual spring, but they have 4 leaves,and look similar to the oval tracks.

      23CA6C35-6A50-4DDF-A84A-879769169F2D.png
       
    • MuuMuu101

      MuuMuu101 Well-Known Member

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      I have them sitting in my garage. They are not installed.

      I currently have Hotchkis springs on my '68 Dart and since my car weighs 3500 lbs with a full tank of gas, my wheels rubs when I have a heavy passenger and/or a bunch of car show stuff in the trunk.
       
    • DionR

      DionR Well-Known Member

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      I put a set of those springs in my car a little over a month ago and assumed that it was just how they were supposed to be. Ordered a set of Andy’s shorter front spring hangers to help the axle location, but haven’t installed them yet.

      After seeing this thread, starting to wonder if maybe it is all messed up. I was surprised at how far back the axle moved, but just figured it was an optical illusion and I was just overreacting. I had a heck of a time getting the bilstein shocks on because they were at such and angle, and sure seemed like the change in the yoke from were it was before was way more than the 1/2” I read about.

      I only put about 50 miles on the car before putting it away for the winter, but it did feel stiffer. But that could be from the new shocks, too.

      Figures that by the time I started buying parts, they were junk.

      Wasn’t there an issue with SS springs awhile ago, too? Seems like the Made in Mexico sticker was related to it.
       
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      • khuebner250

        khuebner250 Well-Known Member

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        Can you measure the arch at the highest point. And are your plans to swap out the hotchkis springs?

        IMG_20181002_180524170.jpg
         
      • 1975abody

        1975abody Well-Known Member

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        Centered the wheel in the wheel well by drilling a hole through the spring pack and moved the axle 5/8" forward.

        Made with pride in Mexico...

        I was thinking about the reverse arch issue on the front segment of the spring, and after looking at the front spring hanger location in relation to the centerline of the main leaf, it appears that once the the car is lowered enough for the centerline of the main leaf goes above the center of the spring eye centerline, the springs have no choice but to go into reverse arch. 38DC798E-DF2E-47CB-BFD8-2A65D1EA2BF3.jpeg
         
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        • DionR

          DionR Well-Known Member

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          I looked at mine this morning to confirm that it also was in a reverse arch condition. The thing I noticed is that the first leaf after the main leaf starts at about 8” or more from the eye of the main leaf. So, in effect, I think the reason it is S shaped is because the main leaf doesn’t have any support.

          I think it is a bad design and would bet it doesn’t match the AFCO spring in how it is manufactured.

          Interesting to me that it took 5/8” to relocated the axle centerline correctly. Makes it sound like the 1/2” long front segment might actually be within tolerance.
           
        • MuuMuu101

          MuuMuu101 Well-Known Member

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          I just measured them and they are 7" from the ground to the bottom of the spring pack (looking at them if they're upside down). They are definitely heavy and seem to be heavy duty/stiff from what I remember compared to the Hotchkis springs.

          The problem with the Hotchkis springs is that they're too soft for a heavy A-body like mine. I know they were originally designed off of Shannon Hudson's Valiant which I'm assuming was about 200-300 lbs lighter than my Dart (my guess for being a Valiant and not having as beafy as a cage as mine). I'm a 200 lbs guy, if I have a passenger I have a minimum of 100 lbs in the passenger seat, and when I have 100 lbs in the trunk my car may weigh about 4000 lbs. My tires rubbed bad on the tops of the inner fenders a couple times when I went up mountain roads or even autocrossed (no offset shackles and 255/40/18 tires). So, I pounded out the fenders (which helped) and was hoping to install these to reduce the travel. Plus, these add a higher spring rate so race car. But I do plan on getting wider wheels and tires in the future now that I have offset shackles.
           
        • dano

          dano Evil Handy Man

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          Bumping this up. I just put the P4529415 I bought a few years ago (also made in Mexico) with the proper front hangers on and am wondering if mine will be trash too. I have yet to load the car as I don't have rear shackles yet, mine were some cobbled together mess. What did you guys end up doing?
           
        • 1975abody

          1975abody Well-Known Member

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          I've been running mine as-is for about 2000 miles.
          No issues...yet
           
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          • dano

            dano Evil Handy Man

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            Which ones did you use? The ones i have are supposed be a +1" lift.
             
          • 1975abody

            1975abody Well-Known Member

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            Mine were zero arch
             
          • racerjoe

            racerjoe Well-Known Member

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            Finally starting to get some miles on mine with the oval track springs and I’ve felt like a dog chasing his tail with incorrect pinion angle vibrations. I went for a ride yesterday to test out yet another pinion adjustment. I finally felt good enough about the EFI tune to get into it a few times and this is what I get home to. Springs are trash. The tire is about an inch from the back side of the quarter. I guess this is what I get for trying to save a few bucks.



            9E410C97-55B5-4BBF-95F3-F5AE14177806.jpeg
             
          • 1975abody

            1975abody Well-Known Member

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