There has been a lot of discussion over the past year or so about what is the correct/best size of front and rear sway bar for C3s.
Many different combinations of sizes have been suggested and some frustration has been expressed at the lack of consensus.
I've come to the conclusion that there is no "right" answer. And the reason is tires.
If you think about the enormous difference between the tires used on the mid years (when the C3 suspension was first introduced) to the 17" wide footprint steel belted sticky tires we have available today, it's easier to understand why a single spring/swaybar combo will not work for every car and/or driver. A suspension designed for skinny tires that don't grip just doesn't work well with excellent tires.
I have read the comment that the huge difference in performance between the C3 and C4 was largely due to the quantum leap in tire size and performance.
Someone recently pointed out that C3s with smaller rear swaybars tend to slowly breakaway in a hard turn with some warning to the driver while C3s with larger rear bars exhibit less body roll but break away quickly without warning.
I've experienced this but with a difference. When equipped with a 3/4" rear bar and Goodyear or BFG 245/60/15s, my SB C3 is very squirrely and will snap to a spin in a hard turn - especially if torque is applied at just the wrong time.
But when equipped with a 3/4" rear bar and 17" 245/40 Yokohamas, it's almost impossible to spin.
In both cases, a 1 1/8" front bar and the same 300 front/315 rear composite springs were used.
Which all goes to say what Zora and Dick Guldstrand have been saying for years - suspensions are a system and all components - including tires- must be considered.
Your input please.........

 

So I never make a blank statement that this works or that causes under
Steer! Every car is different. Anyway I stay out of debates on OS and US.
Car weight with driver/the tires/alignment settings/ride
height can throw any suspension for a loop. Over the years I've heard it
all from the bench racers. Very few of them push their car to the limit
and even fewer have Auto-Xed and even fewer have roared around a road track.

I set my car up like the guys that were getting fast times in my class in C-3's
Then I experimented in minor ways. I'm **** enough that every alignment I
throw two 90 bags of cement in the drivers seat and make sure that I have at
least a 1/2 tank of gas and all the tires have my normal pressure.

I have poly everywhere 1 1/8 and 3/4 with spring adjust ends. I have cheap gas shocks KYB. 550 & 420 steel springs.

I enjoy hard braking and turns more than launching. If I approach a turn way to fast and off of the gas I find myself sawing the wheel back and forth because the fronts are loosing it then biting, loosing then biting. What I’m saying is when I first turn in hard the front tires go into a push condition during over steer. So your natural reaction is to turn out (under steer) to regain traction. My rear is really planted because of 315/35/17 Dunlop p8000's and because of 6 inches of additional rear track than stock. 11-inch rear wheels with 2-inch adapters are 3 inches outboard on each side compared to stock. My fronts are one inch per side wider with 265/45/17. Now if I come into a turn to slow and gas it I can modulate how far the rear comes around. Yes, I have looped it on a fast onramp.





[Modified by gkull, 9:44 AM 11/8/2002]

 

ttt

 

Well, duh. :)

Hell, you could have two cars with two identical setups, two drivers with the same weight, and one driver would think it oversteered too much and the other not enough.

The tires, however, do not go into account with body roll or oversteer/understeer, ASSUMING you're running equal size tires all around. More grip on the rear axle will induce oversteer.With the better grip of the new tires, your car probably still has the same persuasion to swap ends, it's just that you have such a higher grip that you haven't reached the point where it wants to exhibit that behavior yet. Assuming all suspension components are the same and only the tires are different, that is what I have to say.

-Steve

 

Not getting an argument from me! :)

On my '71 you would think it needed a hefty rear bar due to the weight of the 454 and AC. However, a front 1 1/8 bar with a rear 3/4" turned out to be way oversteered. At one autocross I had Mark Madarash (sp?) drive my car (he's a national champion) and he also commented at how very oversteered the car was. After that I replaced the rear bar with a 5/8" bar and handling improved tremendously.

This, btw, was with 255/50-17 tires.

So yes, every car (and in many cases driver) is different and requires a different setup.




[Modified by zwede, 5:19 AM 11/9/2002]

 

So,. . . What happens when you have more traction on the front?

It seems like too little traction on the front with too much traction in the rear would cause understeer (pushing the front tires)

I guess that I'm confused. :confused: