Choosing a stabilizer bar

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So I'm in the process of upgrading a couple of suspension components on my Envoy, which so far has included progressive springs and Bilstein shocks. I'm looking to upgrade the stock 24 mm sway bar in the rear, and as it stands, I've got 2 options: Hotchkis 27 mm Addco 29 mm The stock front sway bar is a 34 mm, so there's no point in upgrading it. The good thing about the Hotchkis is it comes with poly bushings for both the front and the rear bar. They'll need to be greased up real good to prevent squeaking however. That being said, because of the size of the front bar, there's quite a bit of understeer in this application and I'm not quite sure if 2 mm will make all that much of a difference if I opt for or against the Addco vs. the Hotchkis. Any takes?
 
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Bear in mind that the stiffness of a swaybar goes up in power of diameter to the power of 4. 27mm is 64% stiffer and 29mm is over twice as stiff. Your front bar will have a different design, effective length, and leverarms...and will generally be stiffer than the back to promote understeer behaviour. keep stock front and go heavier rear, and you can end up with twitchy things that want to do snap U turns on rough dirt roads. Consider carefully.
 
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A stiffer (not necessarily thicker) rear bar will reduce under steer and make the car feel more neutral. Go too far and it'll feel like a drift car (not exactly but you get my meaning) Do either of those manufacturers quote torsional stiffness? It's a balancing act to get the car to feel 'right', but personal preferences mean you can't just set every car the same, some people prefer one characteristic over another etc, you'll probably have to experiment a little..
 

Falcon_LS

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Thanks for the input. It appears Addco offers a front stabilizer bar for this application (2210) to compliment the rear, which is a ~32 mm (2 mm smaller than stock). I wonder if 2 mm less up front and 5 mm more in the rear would better balance it.
 
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Give it a try! But keep the old bars incase you want to experiment more with different combinations of front vs. rear to get it just the way you like it
 
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It's also possible that the aftermarket bars are made of thicker wall material, adding to the stiffness. An actual torsional stiffness comparison would be ideal (although getting the right balance might still be trial and error). Good luck!
 
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Go with the 27mm bar, and drive with it for a while to see how you like the balance. The bigger bar may be too much. I balanced the handling of my Corvette by going with a smaller rear bar after I took about 120 pounds of weight out of the back. The handling went way loose with the stock big bar, and the car was a fright to drive.
 
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It's an Envoy, not a sports car. Personally, I wouldn't mess with it. If you want to update the links-bushings to make it more responsive, that's one thing. But snap over-steer in an emergency maneuver is not a desirable handling trait.
 

Falcon_LS

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Seems the reviews with the Hotchkis unit are better than the Addco. I'll give the Hotchkis a try and take it from there. thumbsup
Originally Posted By: bigt61
It's an Envoy, not a sports car. Personally, I wouldn't mess with it. If you want to update the links-bushings to make it more responsive, that's one thing. But snap over-steer in an emergency maneuver is not a desirable handling trait.
I never claimed it to be a sports car, although it is a body on frame SUV at the end of the day, and I see where you're coming from. That being said, there's nothing wrong with stiffening up the suspension a bit, so it doesn't handle like Scotch Brite sponge. Having said that, as a PSD, I drive B6 armored GM SUVs for a living. It's not like I'm an inexperienced driver, who's going to take a corner at 100 MPH and induce lift off oversteer just because I got a new stabilizer bar.
 
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There are different types of steel which gives different spring rates. For my truck I went with the Hellwig because it was way cheaper than Hotchkis, was the same thickness and used the same steel.
 
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A stiffer bar can be tuned somewhat with an adjustable end link. I built some many moons ago. What you do is cut out a small section of the end -link spacer and use a small spring to limit the bar's effect initially. From the seat , the car leans in a little , takes a set and keeps on digging as the spring compresses and binds.
 

Nick1994

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I'd definitely go ahead and get a stiffer stabilizer bar. My grandma's Trailblazer drives like a potato around corners. Wayyy too much body roll.
 
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Originally Posted By: Falcon_LS
So I'm in the process of upgrading a couple of suspension components on my Envoy, which so far has included progressive springs and Bilstein shocks....
Sounds almost exactly like what I did to my 2002 Trailblazer about 10 years ago. Installed a Hotchkis rear stabilizer bar kit with front urethane bushings for the stock front bar, Bilstein shocks, and Ground Force rear leveling springs. Far superior handling than when I bought it new. I would go with the Hotchkis because it does need some give back there. I haven't had it happen but I know someone who had the biggest dia rear bar probably the Addco and broke one of the end links, snapped it.
 
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I wouldn't add more rear bar without adding more front bar on a RWD vehicle (part time 4wd counts as RWD for this purpose). When turning, it'll pull more weight off the inside rear tire, reducing available drive traction (especially with an open diff). Basically, add more bar at the non-drive end only and do the rest with different springs whenever possible.
 
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Originally Posted By: rslifkin
I wouldn't add more rear bar without adding more front bar on a RWD vehicle (part time 4wd counts as RWD for this purpose)...
Which is why Hotchkis supplied urethane bushings for the front bar in their rear bar kit - to add more control up front and balance it out. The stock front bar on the '02 is huge and more than adequate. I've been driving it for over 10 year like that so I speak from experience. Excellent handling improvement to the GMT-360.
 
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