Rear Swaybar Question? Sugestions? Your Opinions?

[mellowguy]

Ok, I have a Challenger it originally had a 7/8 (I believe) front sway bar and a 3/4 rear sway bar and a 340 motor. This car will be set up to handle well and go fast in a straight line also (some compromises with this setup). New motor 500 cu. in. stroker motor, lots of aluminum parts, no air, fiberglass hood and fiberglass front bumper. I am taking some weight off the front end. You have a little idea of what I have so far. With respect to just the sway bars. The front sway bar will be a Hotchkis hollow 1 1/4 front sway bar and the rear I have't decided yet. I could use the solid factory 3/4 sway bar (frame mounted). I could go with a aftermarket 7/8 solid swaybar frame mounted. I could go with a hollow Hotchkis 7/8 (rear axel housing mounted). I favor mounting the swaybar to the frame, but open minded. But as far as size of the rear bar from a handling standpoint with my combination what are your thoughts? Opinions? Thanks everybody.

[HP2]

If your going Hotchkis up front, using their adjustable rear bar would be a nice compliment to the set up. Their adjustable design allows you a few different variables to match your set up and preferred feel, . There are very few rear sway offerings out there that allow that.

As far as suggested sizes, actually the 3/4" frame mount and 7/8" axle mount solid bars are actually very close in actual applied rate even though their absolute rates are widely different. Who makes the 7/8" frame mount? I haven't come across those yet, but if it duplicates the factory layout, it will be one stiff mother. Adding this much stiffness to the rear without a corresponding step up in the front will create a car that is very tail happy.

Typically, a frame mounted bar is all sprung weight, compared to an axle mount bar that is partially unsprung weight. Adding unsprung weight is worse than adding sprung weight. However, in a street or pro touring application where you aren't living against the clock, the difference will probably be unnoticeable to all but those few drivers that are intimately in tune with their car's feel. Axle mounted bars will avoid any sort of exhaust interference, if that is already in your car. Frame mounted bars do tuck up nicely out of the way of errant road objects. Since you already have it, I'd recommend sticking with the factory 3/4" rear bar until you get a feel for the car and can decide that you want more or less rear roll rate.

[mellowguy]

HP2  I thought that sway bar manufactures made axel mounts MOSTLY for the reason that on cars without original sway bars they don't have the necessary hardware to mount them that way. The axel housing mounting is universal and can be sold to customers that did or did not have originally a sway bar and say just wanted to upgrade. So they can market to more customers and can sell more products.

[brads70]

I have the Hotchkis sway bars and think they are a great product!    Easy to install ( just a little welding) and the adjustability is a nice feature! And nice and LIGHT!

[Strawdawg]

X2 on the Hotchkis as per the above two posts.  I like mine.

[HP2]

That is true. However, because of the mounting arrangement, the full rate of the bar is compromised by motion ratios and arm lengths.

For example, the stock mopar 3/4" rear sway bar generates 167# of force. With the factory brackets,links and its applied motion ratio of .556, it produces an actual force at the wheel of 93#.  A 7/8" axle hung bar generates 354# of force. With its brackets, link arrangement, and motion ratio of .366,  it produces 130# of force at the wheel.  So while there is a 187# difference between the bars, there is only a 38# difference at the wheels. The larger axle hung bar still applies more rate, but not as much as you would think by casual observation.

Likewise, tubular sway bars work in a similar manner. I have not done the analysis on it, but I'm betting the 1 1/4" Hotchkis sway bar has a similar rate to a 1 1/8" solid bar. So their 7/8" rear tubular bar is going to have a rate closer to a 3/4" solid bar. But like I said before, their adjustble end links allow you to add or subtract applied rate with their bar that others do not have. Plus, like othesr said, they are much, much lighter, than a solid bar so the achieve similar results with less weight penalty.