pittsaj

Just wondering,
What steering parameter most affects the steering's ability to return to center after a turn??

Caster, Camber, toe???

Although handling is good, return to center is somewhat sluggish

I notice that my other cars will almost fight to stay centered and the Vette will kind of wander around center..

BTW
It does have Power steering..

Thanks
Tony

65ZR1

Caster is what returns the wheels to a center position. Just look at the front wheels of a shopping cart. What year is your car?

pittsaj

OK,
Sounds like I need a bit more caster then...

Second question,
Can you have too much caster in a midyear running radial tires?
It almost seems that you can't... I already have what I thought was quite a bit... More shims in rear than in front of A arm

If so, what are the ill effects?


It's on a small block 65 with Power steering

I understand Power steering requires more caster than manual steering.

Thanks
Tony

SWCDuke

Greater caster angles will increase steering effort and kickback. Returnability is also influenced by steering axis inclination angle. This is the angle of the steering axis in a lateral plane viewed from the front, but it's not adjustable. Tires also have a big input and radials tend to have more self-aligning torque than bias-plies, assuming they're 70 t0 75 series.

The nominal caster angle for a C2 is in the range of 1 to 2 degrees. Check yours and set it up to 2 degrees if you want more self centering steering and better returnability. You can also go higher. Sometimes it's just a matter of experimenting until you come up with what you like.

Duke

JohnZ

For improved self-centering and returnability, you're looking for more positive caster (upper ball joint rearward of the lower ball joint in side view); adding shims to the rear of the upper control arm moves the upper ball joint rearward, which moves caster in a positive direction.


[Modified by JohnZ, 5:10 PM 5/13/2002]

pittsaj

Boy I have new questions

I cranked in a degree or so and it is now much quicker in return to center.
Feels much better at speed.
I hope I haven't thrown anything else too far out at the same time.

If I move a 1/16 shim from the front to the rear of the "A" arm on both sides, How does this affect toe??
What is the best way to measure toe?

If the car pulls very very slightly to the right, dose that mean that I need to adjust the toe left??
Which tire, right , left or both...

I'm having fun now :lol:

Thanks Again
Tony

SWCDuke

If you move a shim from front to back it will increase caster, but leave camber about the same. Toe has nothing to do with pull, but you should check it and run about 1/16" with radials. Just use a tape measure and measure as high on the tire as you can. Mark the point on the rear or the tires where you measure, then roll the car forward until you can measure the same marks at the front. The difference is your toe setting and the front measurement should be about 1/16" less than the rear. If the steering wheel ends up cocked you have to tweak the tie rods equal and opposite amounts until the steering wheel centers.

If the car pulls to the right, increase the RH caster or decrease the LH caster.
Go to a good hardware store and buy an inclinometer. You can measure camber directly with it and the caster is the difference in camber readings with the tires turned to extreme right and left lock.

Duke

pittsaj

Duke.
Excellent explanation,
Thanks
That should help me get this front end really tracking...
It is worlds better already :yesnod:
It was setup with way too little caster..
Steering was way too quick, and would not self center.
This made for some white knuckle high speed transition roads. :eek:

The car now handles like it's on rails..
and I'll bet I can still crank a bit of camber up front.
and maybe a bit more in the rear :D

Thanks for all the help

Now this is the way I thought a Vette should handle :D

Tony

pittsaj

Guys,
Thanks again

I removed a 1/32 shim from the right front "A" arm increasing caster on the right side and she is now tracking straight as an arrow. No more pull.

I checked the toe and it was way out as well.. almost 3/8" toe in
I cranked her to 1/16" toe and re-checked the steering wheel now all is well.

Sure makes it easier when you have a better idea what these adjustments affect..

Last thing on the list is to recheck camber..
It looks OK by eye but I will get an indicator on it later in the week

Thanks Duke
I owe you another one :yesnod:

Tony