View Full Version : Sway bar question for my truck....

12-01-2004, 08:48 PM
Im building a 87 S10 that i've dropped a LS1 and 6 speed into and im currently tackling all the chassis work before i move onto the body. Im running a little higher rate spring in the front so i wont really need a big bar up there, a stock one will do. But my 3" drop leafs are a little weak on the rate...not really sure of the rate but there only 3 leaf multi's and not really thick. Pretty much my only option for a rear sway is going to be a universal anti-roll bar like you see for 4 ling drag setup's because of the 12 bolt im using and the rear girdle i can't utilize the rear ZQ8 sway bar and its mounts. I know these type's of anti-roll bar's are really stiff and the one i've found is 1" thick torsion tube which i know is pretty radical for a rear bar. I guess what im wanting to know is what effect would running a really stiff bar in the rear have while hard cornering? I know if i knew the rear rate and weight it would help out alot but i don't have access to scales and my project is still not fully assembled. I could call and find out the rate on the leafs but i doubt just knowing that is going to help without getting a static weight for the truck. These trucks have a factory understeer problem, i was wondering if keeping the rear bar really stiff would get some rotation and help me counteract the understeer. Or is it going to be WAY too stiff and cause me to have severe oversteer? This trucks going to see more street time than track time, but i can live with a stiff ride and sacrafice a little travel.

David Pozzi
12-01-2004, 09:10 PM
The thing I'd look at first is if the front suspensoin geometry is good. If so, then the higher rate springs would stiffen the front and you'd have more understeer than before, especially with no rear bar.
If your rear bar has fairly long arms, it won't be all that stiff. If the arms are somewhat short, see if there is room to extend them if you need to soften the rear rate, that would add some tuning room. You can also mount the rear bar in stock type rubber bushings to soften the rate if needed.

12-02-2004, 09:45 AM
The anti-roll bar i have in mind has rod ends instead of bushings to connect it to the housing. Unless there is some way i can space the factory ZQ8 bar away from the rear end to clear the Moser Girdle, and still be able to clear my fuel cell mount...this is about the only kind of sway i can use on the rear. So basically what your telling me that it would be better to not have a rear sway with a soft rate in the rear, opposed to a overly stiff swaybar?

David Pozzi
12-02-2004, 11:33 PM
I forgot to continue my first sentence above. If ft geometry is not very good, I'd try to improve that before working on the bars and springs.
A heavier front bar or stiffer front springs can actually improve front end traction without increasing understeer if the geometry is bad, less lean helps keep the ft tires flat on the ground in that case. The cornering traction gained can exceed the added load of the stiffer front suspension. Of course it's hard to tell from here if that is what will happen in your case...

It sounds like you are going to need a rear bar. Luckily you can allways try going without it and add one later.

Another way to mount a rear bar is to hang it behind the rear axle on long links from the frame, then run the end links to the rear axle housing. The second gen Camaros do it that way, and the bar does not add to unsprung weight. Making the arms longer will soften the bar, making the bar wider will soften it too.

If you can mount the factory bar, you can compare it's effectiveness by disconnecting a link on one side.

12-03-2004, 09:20 PM
Ya, the factory ZQ8 bar installs exactly like the 2nd gen sways do. The bar hangs from the frame on long end links and connects to the rear end housing at two points on the axel tubes. I may try and use a stock bar, i'll either have to space the bar out away from the axel tubes enough to keep my girdle or im going to have to run a regular diff cover. I think i may have enough room infront of my fuel cell to mount the stock bar....but it will probably be a little close. I guess i'll try the stock bar first before trying to go with one that's designed for drag racing. Thanks for your help btw.