Fixing the understeer... L-body.

[BadAndy]

Quote:

Originally posted by omnivore I haven't seen the LRE swaybar, but Addco's and Quickor's do not attach to the body...they simply bolt up to the bottom of the torsion axle like the stocker is welded. They do use links to attach it to the trailing arms on either end, but otherwise, it is an axle only attachment as far as i have seen.

Nope, (on the Quickor unit) they attach to a end link which is stationary with the chassis by virtue of the bracket that the trailing arm pivot point is attached. Imagine the trailing arm pivot bracket (that bolts directly to the cars chassis of coarse) with a extension that the endlink attaches to.......it would be the exact same as if it went straight to the chassis. The Addco unit attaches directly to the cars frame rail also via endlink setup. So indeed they both do attach to the frame and not solely to the trailing arm itself....such as the intergrated stock torsion bar.

[Frank]

i think you all missed my post... especially since i read andy's post, wrote my post, and it somehow squezed itself before andy's post.

take a look at it.

frank

[BLUEBALL]

I had an Addco a couple years back on an ITB Omni. Didnt go to frame.
Also before you throw all this add on stuff at it, has align been checked or adjusted? Go w/negative camber in ft w/0 toe and maybe some toe out in rear. this is to start. Shocks/struts/bushings ok and tight? Might as well start w/the not adding weight to car stuff.
The weld on rear plate makes the rear wheels come off ground easier w/braking/turning swift too. Gets some peoples attention sometimes w/3 wheelin around corners

[Vigo]

Quote:

All of our needed wheel travel for normal everyday driving is when both wheels are traveling evenly (speedbumps for example) and this would not be interrupted with a rear swaybar as it would just rotate in is bushings......

the difficulty i see in connecting a swaybar to the axle and to the body is that the distance between the axle and the body changes when the suspension compresses, and i cant think of how the sway bar would compensate. i can see how quickors setup works , but the addco still seems like it would bind up the suspension unless it were attached the frame with the pivot point exactly in line with the trailing arm pivot point.

there probly something simple that ive seen a million times that im just missing..

anyway instead of spending 160 bucks on quickors swaybar, i just grabbed a whole daytona es rear axle (with disc brakes ) at a junkyard for 60 bucks. the internal swaybar is VERY noticeably larger than the one in my dynasty. im hoping between that the the brakes that my car will drive very differently

[BadAndy]

Chris Faulk has nice pictures of his Addco swaybar install with pics of the frame mounting

[thatsbc]

If you check out the latest Grassroots Motorsports (September 2003, on newsstands now), there's some info you might want to read. And some good pics, too.

bc

[derek502]

I installed the piece of steel on my 87 GLHS just like the GRM mags article,,it works great but the squeeking noise from the clamps drove me nuts,,,I had it welded up and the noise is 99% gone. I have 2 or 3 of the metal plates for sale. they are 4'' wide by 40'' long. I had to buy a 10ft piece when I did mine.
I'll take $25+shipping. Seems like I drilled the holes for the clamps on some of them."thumbs up

[glh-s-car-go]

My Quickor L-body anti sway bar does not attach to the chassis at any point. The transverse bar bolts over(under) the stock bar and the legs are attached to the trailing arms via end links.

As for reducing understeer without modifying the rear suspension, doing an alignment is the way to go. In the past I have run 2.5* negative camber up front with 1/8" toe out. For the rear, I have used 1/4*negative camber and 1/32" toe out each side(1/16" total toe out). The only problem with the rear toe out is that you can get snap oversteer. When it comes, watch out.
Most people don't know/realize that the rear shocks can be converted to coilover in a snap. If you only want to do the rear, you can get a 2.25" sleave and hat then the 2.25" spring you want. Then you don't have to worry about welding or bolting on a rear bar.

FWIW, my current set-up is as follows, Front- revalved koni, 350# spring, 2*negative camber, 1/8" toe out, and poly bushings on stock bar.
Raer- revalved koni, 300# spring, 1/4*negative camber, 0 toe, stock bar, and 1 1/8" Quickor bar.
I am still playing with spring rates, but it feels quite netural at the limit. I'm still trying to dial in tire pressures on the new tires(Kumho Ecsta V700's vs VictoRacer V700's) I used to run 50-52 psi in front and 28 in the rear. But the Hoosiers I've been trying out seem to like mid 40's front and low 20's rear. Tire size is 225/45/15.

[Vigo]

i was already intending to run 0 rear toe whenever i get a full alignment (probably after i change springs/struts), but i already get snap oversteer on my stock suspension, only when im NOT inducing it with the brakes. luckily its so rare ive got it figured out so it doesnt surprise me anymore (whew).


my quiestion is how much camber can you put in the back, and how much you really need on this kind of suspension.

also, if im still driving the car on the highway, and occasionally over 100 mph, how much toe out, if any, should i use?

[BLUEBALL]

i never really went more than -.75 deg in rear and no more than 1/8 toe out. probly better off for street use going 0-1/16 toe out. also ran -1.5 to -2 deg in ft with 1/16 toe in to 1/16 toe out.
i had occasional instant oversteer due to tires rubbing coils in hard turns sometimes,may wanna check that too.
many years ago i went to hallette for the 1 lap,and a charger there had like -3.5 in rear

[OmniSRT4]

Quote:

Originally posted by BadAndy This works great as well as it will help in keeping the axle from twisting and bending however it has nothing to do with the axle in relation to the frame/body which is what the sway bar does. Nice tip!

As for it not effecting the car like a sway bar does....well in an L-body it would. The entire L-body rear axle is designed to act like a sway bar. Boxing it up would make this twist axle (crossbem) MUCH stiffer. The crossbeam is offset to the back and anything that stiffens it will act the same as if you installed an aftermarket sway bar.

Ever notice how a stock sway bar is just a straight bar welded across the crossbeam? This is exactly the same as boxing in the beam exept that boxing it in would make it even stiffer.

This method is no better or worse than adding a 1 1/8 aftermarket sway bar, but it is FREE. I assume this is why it was done since saving money is the KEY to winning the GRM challenge.

[OmniSRT4]

Quote:

The "idea behind ruducing the twisting of the trailing arm style 1 pc axle" is not the whole idea behind a sway bar.....it is however better than not having anything at all.

In other TD's that is true, but the L-suspension is quite different from other TD's. In fact reducing the twisting IS the only real point of the sway bar in the L-body design.

Even if the L HAS no swaybar, its suspension still acts like one.

[OmniSRT4]

Quote:

Originally posted by BadAndy [b]I am aware of how the "torsion beam" setup functions. If it were true that it is unnecessary to have a conventional swaybar on the rear of a solid axle car then it would also be true that manufacturers would not waste the extra expense, yet conventional swaybars have been placed on solid axle cars for quite some time......especailly when it came to competition purposes.

The inherent flaw to this is that the L suspension is not a "solid axle" design and it does NOT need a sway bar. If chrysler had made the crossbeam solid instead of a hollow it would be extremely stiff (just as if you had installed a huge sway bar) but this suspension was designed for an Omni and isnt SUPPOSED to be that stiff.

It is far easier for them to weld a solid bar on it (as in the glh and SC) than to remold the part as a solid peice.

In fact, the one major pluses of this design is the lack of a need for swaybars! (cheaper to build)

[OmniSRT4]

Quote:

Originally posted by glh-s-car-go [b]My Quickor L-body anti sway bar does not attach to the chassis at any point. The transverse bar bolts over(under) the stock bar and the legs are attached to the trailing arms via end links.

As it shouldn't. Andy is confusing Solid Axle TD's with L-body's which are completely different.

Heck, a lot of people don't even know they are different.

The L-body system is actually far superior.

[BadAndy]

Quote:

Originally posted by Akuma As it shouldn't. Andy is confusing Solid Axle TD's with L-body's which are completely different. Heck, a lot of people don't even know they are different. The L-body system is actually far superior.

I know they are different and I'm not confusing the two. I am however confused in that both are a solid design yet the addition of a swaybar to one will perform as intended but yet the addition of a swaybar to the other will not. I was not aware that the L body swaybars do not have a endlink setup that attaches to the frame in some way( as is available for the other TD's ) so therefroe I can understand how making the axle itself more rigid would have the same function as a swaybar that solely mounts to the the axle.