Corner Balancing Using Adj Sway Bars
 

What is the "down side" of performing a rough corner balance using the adjustable drop links on my front and rear adjustable sway bars? On an otherwise stock 1976 911, this would be a lot easier than pulling torsion bars; and I'm happy with my current alignment and ride height. I know that this will produce some straight-ahead stiction in my sway bar bushings, but it should be considerably less than the friction that the bushings tolerate during normal cornering, and I wouldn't go too far in the adjustment anyway. A friend is about to invest in digital scales so I have an opportunity to play. What do you guys think? Thanks.

Howard

I *think* you should get the car on the corner scales...and first see what you have before you make any changes.

Then... would suggest getting a large mug of your favorite warm ( cold?) drink...and sift through this BBS for "corner balance" threads.

Then.... post again with your questions :)

---Wil Ferch

Thanks, Will. I've spent the last two hours reviewing prior threads and learned a lot. However, no one addressed the possibility of modifying the balance WITH the sway bars (instead of the torsion bars), rather than disconnecting them.

Howard

If you really think about it... I would guess it *can* be done, but you'd have the additional complication of the "non-independence" of the two sides. This corner balancing thing is difficult enough to grasp ( and do) as it is...and if you tweek the sway bars, not only would (say) loading up the RF cause the LR to load up ( as is normal)...you'd also have to worry about the inter-play left-to-right of the sway bar you're adjusting.

My head's spinning already.....:)

Why not see what you have first ???

---Wil

I will certainly see what I have to start with before I fiddle. In fact, it can't be too bad because the car autocrosses great; left, right and straight, braking and accelerating. If I do any adjusting at all I will limit it to 20 pounds max change on any wheel.

Howard

If you have any pre-load in your sways when your done with the corner balance then the car is going to be madly unpredictable when cornering. If you are talking about setting the car perfectly level and then purposely preloading the sways in order to get a corner balanced car, I dont believe that is possible. Or if it is, Im not aware of the benefit.


ADD: actually now that i really think about it.... it would be possible but what about the times when you catch air hauling as$ down that b!tcthin country road. Wouldn't it screw with the mid-air rebounding of your suspension.

Pardon me, but are those "Bad Idea" jeans you're wearing?

Your fronts are adjustable with just the screws on the T-bar end plates. No need to mess with the adjustable sway bars. So, that's easy, and the correct way to corner ballance. As for the rear, do you already have adjustable springplates? They weren't offered in 76, but maybe a PO already did the upgrade (as I have). If not, then I wouldn't mess with them.

Thanks, all, for your comments. Chili, I don't have adjustable spring plates, but your suggestion about the screw adjusters on the front t-bars is a good one----just as easy as purposely preloading an appropriate sway bar. I'm still not convinced that there is a functional difference between a t-bar adjustment and a sway bar preload to improve corner balance.

Howard

Bad Idea...bad bad bad...

OK so you preload the suspension when the car is in a static position sitting on the scales...you get the corner weights where you want them...

No go out and drive the car..

The handling will suck...

Every chassis set up guide you will find recommends disconnecting the sway bars prior to fiddling with the corner balances.

Say you preload the left front to balance the car.. ... now make a nice long right turn.... now you have not only the preload of the sway bar+spring rate +the sway bars working rate.... Turn left and all the equation becomes even wierder....

Just using the adjustment screws on the front t-bars should get you a close corner balance.....

Make sure you disconnect your sway bar beforeyou do any adjustments.

If you preload the sway bar to adjust the weight balance, the shocks and tbars will end up have an uneven load on them and give different rebound charactristics....car will handle like moose and squirrel on quaaludes...

Balance the car with sway bar loose. Then do the sway bar adjustments.

I think if you can't balance the your car with the front adjusters and need to start rotating the rear torsion bars somethings been set wrong all along. By the way, the adjustable rear springplates don't look like the aftermarket ones you see in the catalogues. Preloading the sway bars is not the way to go!

Yes......a BIG "NO, NEVER" on the sway bar as adjusters.

You get points for thinking of creative solutions.

But no points for the answer. Not a good idea.

You are dialing in pre-load such that you will experience different roll stiffness left and right. Handling will be very uneven and oversteer/understeer tendency will be different in left and right turns.

Maybe if your running NASCAR this will work, but for the rest of us - no.

Just use the adjuster screws as mentioned above. It's easy if you have the scales.

I would like to take Howard's idea a little further:

Instead of all that troublesome, inconvenient, under-the-car, drop-link adjusting, why not just do corner weights with tire pressures? And for really large discrepencies, perhaps a little different tire size?

This could go hand-in-hand with the "easy to use" checking your ride height with the top if the radio antenna.

Let us know how it works . . .

Ed LoPresti
RacePro Engineering
New York

Adjusting tire pressures is too inconvenient. You have to keep topping them off as they lose pressure. Too much work.

Better yet Ed, how about strapping balast weight to each corner? You could put it in the trunk and engine compartment. :p

I've got an old barbell set gathering dust in the basement. Maybe I can put the weights to better use ;)

Ok, ok, guys. I yield to your experience. I like your alternative balance and ride height suggestions. They inspire me to share with you my battery replacement project. I have duct taped 150 "D" cells to the bottom of the car in a parallel/series network to simultaneously improve my polar moment and center of gravity. Cool,eh? On an appropriate thread I'll detail my brake line weight reduction scheme.

Howard

Ed, Chuck - you guys are on the right track but are not going far enough....
four on-board tire pressure adjusters from a H1 Hummer, four load cells, a bit of computer, and you could have real-time tire pressure based corner balancing

Sounds like a plan, I think.

Bob Donally
'84 Carrera

then why touch it? ultimately it comes down to how the car handles.

btw - bad idea;)