Front Sway Bar Difference - from 1" to 1-3/8"?

Discussion in 'The whoa and the sway.' started by 73 Stage-1, Jun 28, 2019.

  1. 73 Stage-1

    73 Stage-1 Dave

    While I have the front of the '73 up in the air and steering box heading to Carhex, will upgrading the stock 1" sway bar to the Hotchkis hollow 1-3/8" going to make a big difference in feel? And more important, is it going to interfere with the oil filter removal?

    The front end has stock replacement springs with a coil cut and Koni adjustable shocks - with 225/70/15 tires. The rear has South Side Machine lower bars along with a 1" sway bar and what I believe to be AC Delco gas shocks.
  2. BadBrad

    BadBrad Got 4-speed?

    Does it oversteer or understeer currently?
    73 Stage-1 likes this.
  3. 73 Stage-1

    73 Stage-1 Dave

    Good question - it's been a while since the car has been driven spiritedly, but considering how nose heavy it is, it is relatively balanced. It isn't what I would call a well handling car though, hence starting with the freshening the steering box. Probably one thing at a time will be the best approach.
  4. Golden Oldie 65

    Golden Oldie 65 Well-Known Member

    Overkill. I upgraded some years back to 1 3/8" front and rear bars. I don't go road racing with the car but do get heavy into it sometimes on freeway ramps and other corners. My problem was the car sat pretty flat but would slide the front tires when I got too aggressive. I had 215/70-15s on the front. There just wasn't enough rubber on the ground to hold it but that's about all I could get under it without rubbing. On one of the suspension conversations here it was suggested that maybe my suspension was too stiff I and that I might try a smaller bar in the front so it would put more load on the front tires, so I went to a 1" front and rear bars and sure enough, it worked. The car corners better with the smaller bars. I never would have guessed that. I probably could have also remedied it with shorter, wider tires but that's not the look I wanted so...……………..
    73 Stage-1 likes this.
  5. 73 Stage-1

    73 Stage-1 Dave

    Thank you both - for making me think and a real world example!
  6. knucklebusted

    knucklebusted Well-Known Member

    A bigger bar in front will keep the front flatter but you need the rubber, as Golden Oldie 65 noted, to make it usable. If it is too stiff, you will scrub the outside tire and under steer. Generally, under steer is preferred but closer to neutral is always better than massive under steer.

    Additionally, you need to make sure your have at least -1/2° to -1° of camber and as much positive caster as you can get to make the tires plant better in the turns. I have been carving corners for 40+ years and had 60 series radial tires all the way around on my car back when everyone else had VW tires up front and N50s in the back.

    Both my cars are setup to under steer at the limit of tire adhesion with over steer from just a bit of throttle. Both cars are tubular upper front control arms, TA sway bars and factory rear bars with boxed control arms. But the front end geometry is much better than the factory ever thought it could be.

    You can see from these pictures that the tires lean out at the bottom on the outside of a turn. They plant themselves like a motorcycle tire.
    [​IMG] [​IMG]
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  7. Bygblok

    Bygblok Well-Known Member

    I went to a 1 5/16” bar on the front of my 66 Special and it really made a huge difference. I also run a 255/40-18 on the front with a 2” umi lowering spring that has a pretty aggressive rate. Almost a full degree of negative camber and 3 degrees of positive caster and a quick ratio steering box. With the 1” bar on the rear and 275/40-18 tires it really corners nice and flat. Can’t wait to have bigger power to put it all to use. For a generic driver car a 1.25” front bar front and a 7/8 rear would really make a huge difference.

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