lanos rear strut bar... is it useless??

[MMamdouh]

this is one of them articles that is going to be a bit controversial and i need your feedback to validate my assumptions and theory here...

i was considering a rear strut bar for my lanos as i tried the front strut bar and man... it really changed how the car handles... and then this idea struck me: as far as i think... a rear strut bar on a lanos (and practically any car sharing the same rear suspension design) will not enhance the handling of the car in any way or form... here are my assumptions that led to my conclusion and i need your opinion:

the theory of a strut bar is to add chassis rigidity to stop struts from moving inwards in corners due to stress and weight shifting thus keeping tires in perfect contact with the road and also redirecting part of this force to the inner spring rather than having it all on the outer spring thus adding more stiffness to the suspension and reducing body roll... it is like having stiff suspension that only kicks in during corners even though you have OEM springs.

now the key factor here is the force generated by body lean during corners and shifting body weight and its effects on the strut towers... thus making a strut bar effective in a McPherson suspension as the strut tower is the place were car weight is concentrated... now on the rear of a lanos... we have a semi independent suspension setup with short springs... the strut towers in the back are actually upper mounts for rear shock absorbers and the weight of the car is not at this area at all... the weight is at the bottom were the springs are.

imagining a lanos going into a roundabout at constant speed and going round and round... assuming no road bumps and no speed/steering angle changes then at this situation the shock mounts sees no stress what so ever as the weight of the car is slightly shifted to the outside spring and the effect of that is at the bottom area of the chassis were the spring sits... accordingly their is no strut movements at all and hence a rear strut bar will not be doing anything as their is no stress to transfer and no movement to stop... hell i recon you can remove both shock absorbers and drive the car into this roundabout and you won't feel any handling difference in such test

given this fact... tire position on the road doesn't depend on shock absorbers or strut geometry in this kind of suspension... it is basically down to how stiff the rear suspension member is... so if anything should be done to enhance the handling of a lanos (or a car with similar rear suspension) will have to be focused on the rear suspension member... also the concept of "weight redistribution between springs" is not applicable here as the top of both springs are in direct contact through the car's chassis already and their is no "chassis flex" during cornering

please assess my theory and assumptions and give me your feedback

MMamdouh

[daewoomofo]

hmmm. i did make one a long time ago and im still useing it on my lanos today. what you said makes sence, it actually makes alot of sence. it may have been in my head but i want to say that i noticed some improvement with the RSB. it may have just been structural ragididy, but i want to say that i did notice some slight gain. i have recently been thinkiing about taking out the RSB, just so that i can have some more trunk space, since it doesnt do much (if anything) and i never made mine look good, its still in its prototype form (ugly as shit).

[Rodd1s]

one thing that's guaranteed to stiffen up the rear end properly is installing an anti-roll bar.

i've been looking at getting one from a calibra or corsa b (seeing as they're only about £30 for a second-hand one). obviously it will need custom brackets etc to make it fit and work smoothly/rattle-free.

[2woo4you0]

I plan on using one from a Saab 9-3 as it should work perfect, just need to weld up mounting tabs which is simple. I think the OE 9-3 would be perfect. Just waiting to find coil-overs so I can have the anti-sway bar mounts welded up same time as rear reinforced for the coil-overs