Sway bar with large diameter t-bars?

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paulclark

paulclark

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Will a stock front sway bar make much difference with heavy torsion bars, i.e. over an inch?

I know a sway bar will make a big difference with lower rate springs in preventing side roll, but with heavier springs and so much less movement, will it matter much? Can you still feel the difference?
 
Yes, it will. T bars have the job of "Up and Down" movement. There side to side sway or tilting control of the car is limited.

The anti roll bar or sway bars control that aspect of the car. It's there job. And there's trouble if someone else tries to do there job (reliably) in part or full.

Parts on a car are like a union shop. Every one has a job and that's there only job.
 
In some race only chassis it's possible to not need a front sway bar. In a relatively heavy car especially front heavy car will always need a front sway bar. The torsion bar and sway bar works together to control the roll. Your car needs X amount roll resistance which is handle by both the torsion and sway bar. The bigger torsion bars help but I'm sure your car still needs more than the stock front sway bar.
 
When I went from stock 340/318AC t-bars to .99" MP t-bars AND kept the stock sway bar, the car still had large increase in roll resistance. When I added/found a $40 used 1 1/8" sway bar it helped even more in tight high G hard cornering.

Roll resistance is calc'd accounting the sway bar rate and wheel rate.
 
autoxcuda said:
Roll resistance is calc'd accounting the sway bar rate and wheel rate.
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This is right.... the sway bar does not contribute to the vertical spring rate at all. But both the front springs (T-bars in this case) AND the sway bar are part of the roll rate. Having a sway bar in the system allows you to adjust roll rate separately without effecting the vertical spring rate, but both parts contribute significantly to the total roll rate.

To the OP, yes the sway bar can make a serious difference in handling. With the thicker t-bars upfront, you can use the sway bar more for tuning oversteer or understeer in the car, rather than controlling total roll angle on the body. But if you are never pushing the car hard in turns, then it may be less important to you. If you want to know its part in controlling roll, just disconnect one end of the sway bar and go through some turns!
 
I would look at Firm Feel in Vancouver, WA. They're a local company making exceptional products for our cars.
 
nm9stheham said:
the sway bar does not contribute to the vertical spring rate at all.
Click to expand...

This isn't completely true. It doesn't effect vertical spring rate if both front wheels are moving together, if hitting a bump with just one wheel it does try to transfer some of the vertical movement to the opposite wheel.
 
Yes, use the anti roll bar. Keep in mind there is a necessary balance between front &
rear roll stiffness, you can end up w/a push monster if the rear isn't upgraded as well, so
start w/the OE bar and see.If you've upgraded the rear springs &/or added a rear anti-
roll bar then you will probably be OK w/the bigger frt. bar.
 
ChrisPerry said:
This isn't completely true. It doesn't effect vertical spring rate if both front wheels are moving together, if hitting a bump with just one wheel it does try to transfer some of the vertical movement to the opposite wheel.
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Not really..... if the 2 wheels are not moving the same amount, that is the very definition of suspension or chassis roll..... and the sway bar raising the other wheel is adding roll stiffness to the system, not vertical stiffness. Look at how a sway bar is mounted and works; it can't exert any vertical force whatsoever.
 
Okay, good info all around.

I would have guessed that as you increase the rate (diameter) of the T-bars, you wind up with less up and down motion on either side for a given amount of cornering force, making less for the sway bar to do compared to softer springs. If that were true, I'd think you'd want to go with a stiffer sway bar when you have stiffer T-bars. if so, there would be a point at which the springs were heavy enough that the stock sway bar wouldn't be worth bothering with, and you'd need a heavier sway bar to make a difference.

With the thicker t-bars upfront, you can use the sway bar more for
tuning oversteer or understeer in the car, rather than controlling total roll
angle on the body. But if you are never pushing the car hard in turns, then it
may be less important to you.
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That's important to me, I care more about handling turns than pounding the quarter mile.

More front sway bar stiffness makes for more oversteer/less understeer, is that how you mean?

Bottom line - I hear you guys saying it's worth adding even a factory sway bar even with heavier springs, so i'll go forward with that plan.
 
paulclark said:
That's important to me, I care more about handling turns than pounding the quarter mile.

More front sway bar stiffness makes for more oversteer/less understeer, is that how you mean?

Bottom line - I hear you guys saying it's worth adding even a factory sway bar even with heavier springs, so i'll go forward with that plan.
Click to expand...
Yes, a stiffer front sway bar will tend towards understeer, and a stiffer rear will tend towards oversteer. But a particular car may not need one on either end based on the roll rate provided by the main springs alone. As examples, IIRC some Porsches do not have a sway bar at one end, and many stock RWD cars come with only a front sway bar, as it tended to understeer that way and makes people back off before they get into oversteer and spin out.

The generic solution for better handing is to have both front and rear ones.
 
Commando66 said:
I would look at Firm Feel in Vancouver, WA. They're a local company making exceptional products for our cars.
Click to expand...


Yes, give them a call. When you do ask to speak with Dick. He's a wealth of knowledge. All of their R&D has been on the track and has been proven.
 
One of my current A bodies has good size torsion bars (1.14") and and a stock sway bar (73 type) it also has shocks that are compression adjustable. I was really close to bolting in a Hotchkis sway bar ( like laying on the floor with it in my hand ) but decided that I would just start playing with the shocks first making them stiffer to stop the car from rolling over in turns, I drove it like that for a few months and now in not 100% sure that it needs a bigger sway bar.....and then it started snowing here in Canada.
 
longarm said:
Some more info.

http://www.houseofthud.com/cartech/swaybars.htm
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What+a+fantastic+roll+_b9fadc09d1e5f28f717e2bcb3d05d72a.png
 
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