Gimme the subframe connector skinny, please!

Discussion in 'Suspension, Steering, Brake & Wheel Topics' started by slayer021175666, Jan 13, 2021.

  1. roadrace2

    roadrace2 Veteran Member

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    Ive been driving on solid frame mounts for 20 years. No ride issues. Springs/spring height / suspension travel/dampeners are the main reason you have a rough ride in your Camaro.

    Weld in sub frame connectors with solid bushings were my choice and I would never go back.
     
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  2. flht99b

    flht99b Veteran Member

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    It shouldn't be news to anyone that the 1st and 2nd gen F bodies as well as X bodies were fairly flexible platforms. The replacement of rubber subframe mounts with a harder material as well as SFC's does help stiffen the entire body/frame structure. It is true spring and shock selection play a major part in ride quality and handling, they should be carefully matched to the car's intended usage. The stiffest shocks and springs with excessively high rates makes for a miserable car to drive long distances. There is a trade off with NVH, noise, vibration and harshness especially when going to solid mounts and or hard suspension bushing points. A car that is primarily driven on the street regularly, SFC's and solid subframe mounts does not normally increase NVH to a point where it is objectional to most. But NVH is subjective, everyone has a different threshold. You can learn a lot by looking at modern cars body/subframe mounts and suspension bushings construction/materials as to how the OEM's handle frame and suspension isolation points in a way to increase rigidity while maintaining satisfactory NVH. My personal 71 has solid PTFB subframe mounts with global west subframe connector's. Both made a measurable improvement in rigidity of the car allowing the suspension to work more efficiently by reducing body/chassis flexing in all planes but without question NVH has increased but not overly so as to make the car uncomfortable. BTW my SFC's are bolted in.
     
    Last edited: Jan 18, 2021
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  3. slayer021175666

    slayer021175666 Veteran Member

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    So, I thought SFCs did it by themselves. Does adding solid body mounts combine the rigidity of the body and frame together to get strength from both? Therfore, the frame getting added stiffnes because of the body? Having a little trouble wrapping my head around the concept.
    Am I smellin' what you guys are steppin' in or, am I way off?
     
  4. flht99b

    flht99b Veteran Member

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    Short answer is yes. If the subframe is softly isolated from the main car body, it's motion will transfer into the SFC's minimizing their effectiveness.
     
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  5. Fbird

    Fbird Veteran Member Lifetime Gold Member

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    yes ...since the front "sub frame" is a bolt on unit...trying to maintain its structural rigidity relative to the 3,000 lbs it is attached to is difficult so by making the attachment SOLID the front subframe can and will improve its rigidity allowing the SUSPENSION to actually do its job. By welding in the SFC you are now removing the dependancy of the "bolt on" location and tying in all the suspension mounting points to the entire floor pan/rear quarters and roof. When you add a 12 pt roll cage you are then TRIAGULATING all those hard points making it even more RIGID.
     
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  6. Popper

    Popper Veteran Member

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    Don't forget Hotchkis... They are pricey comparatively speaking (double the price of most) however they do tuck up nice and are more of a factory look. GW and PTFB tuck nice and look real similar in styling. I personally am not a fan of the GW as i don't like the tubular look (to each their own preference). With that said i do like the way that GW tucks up in the rear mount as it follows the factory subframe lines better, they kind of disappear into the rear subframe. I have the Summit racing units and they work but man of man are they hideous, they are a straight version of the GW and PTFB and hang a little too low where they meet the front subframe
     
  7. 8pack

    8pack Veteran Member Lifetime Gold Member

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    I have welded in connectors with poly bushings which was the best option 20+ years ago. If I was doing it now I would go with the solid bushings. My poly bushings still look new, but when you Jack up the car you can still see some consequential flex. Mine is a t-top car so that doesn’t help in terms of chassis structure. But my tops fit much better with the welded in connectors.

    Changing to solid bushings at this point means cutting out the sub frame connectors and probably making a mess of the floor pan. You only get to Weld them in once! So go with the solid mounts....

    Also when you go to weld them in everything needs to be sitting exactly as it would be on the road and all frame measurements verified. Otherwise you will lock in whatever body sag there is from the front end hanging. Even with solid mounts it is going to flex a bit....
     
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