HWO

Howdy, i am just about to install my camber/caster plates, they are only adjustable on one axis not two, should i install them on an angle so the more camber i run the more caster i also get or should i not worry about adjusting the caster and just set them up to adjust camber only?

What effects have people had changing the caster?

car is a T2 FC

Cheers
Shane

abeomid

Where technically for every degree of camber, you need 2degs of caster

Silkworm

I dunno about that, but I run 2.5 neg cam, 6 pos caster.. The caster is a bit much, the car definitely tells me about it.. Steering wheel is constantly fighting me through corners, and one spin just about broke my finger as the steering wheel spun around But the car feels great!

For an auto-x only car, the 2.5 neg camber is fine, but a street car, the most I'd go is about a degree to 1.5 neg. Caster, 4 is good, 6 is better, but be prepared for the weird feelings driving the car.

PaulC

Node

iTrader: (1)

I know what camber is. What is caster and what does it do?

HWO

caster is the incline angle (fowards backwards) of the strut, camber being the inwards/outwards.


Paul- is +ve caster forwards?

Adsy01

positive castor is when the strut tops are leaning back toward the firewall.

on my 1st gen i run 2.5 neg camber and 6 deg pos castor.

i personlly like as much castor as possible as it aids high speed stabilty, though the steering gets heavier with the increase in positive castor too (not easy to park ect..)

Node

iTrader: (1)

You stated what positive caster does. But what about more neutral caster.

abeomid

well with netural caster, you have the easier steering, but you lose the high speed stability of the car. Toe/Caster both depend on what you want to to do. If you have an autox car, you want around -2.5Camber, +6 caster, adn 1/16" toe out in front. if it's a road race car, camber and caster are the same, but then you don't want that toe out since the high speed stability is better with no toe or toe-in

HWO

more caster gives you more turn in, well that has always been the golden rule i have heard

HWO

so should i position my plates to always be at 6 degrees caster, so i can just adjust my camber or should i set them up on an angle so i have 6 degrees caster at the same time i have 2.5 degrees camber and so if i have more camber i also have more caster??/

Rob500

Excessive castor can cause a change in the car's balance during cornering. By taking weight off of one front wheel/diagonal you end up with weight transferred to the opposite diagonal.

Rob

Silkworm

Sorry Rob, but caster has zilch to do with cross weights. You're thinking ride height and coil overs.

More caster gives you a stable car at higher speeds. Less caster gives you a car more willing to turn in at low speeds, but unstable at higher speeds. For turn in, look at 1/16 to 1/8 toe out on the front.

HWO, get camber to 2.5, if you can get caster to 6, good, but if not, don't sweat it. Camber's much more important for tire wear and grip.

PaulC

Rob500

I think it has been shown that increasing castor does change the balance of the car under cornering. I agree that under static conditions with the car sitting on the scales changing the castor does not affect weight distribution. In addition if the car were set up with zero castor the tires would turn around a vetical axis, and under this condition turning the sterring wheel would also not affect weight distribution.

But when you add castor and then turn the steering wheel the front tires do not rotate around a verticle axis. This changes the weight each of the front tire carries. And therefore I believe you do have a change in balance.

I understand that you add castor to get stability. I'm saying that you can take it too far. There are trade offs in adding castor.

I think that if you were to set your car up on scales and note the weights then turn the front wheels left you would see the right front tire get lighter and the right rear tire get heavier.


Rob

Eggie

Rob's right on the money about caster and weight jacking. When I started kart racing a few years ago, I was amazed by how much muscle the steering takes. Karts use a ton of caster with a large scrub radius to pick the inside rear tire off the ground when you turn in, and that lifting comes from your arms...

Silkworm

oh, ok, I see what you mean.. I'm not sure I buy that it has a dramatic effect on the balance of the car, but I can see where you get the idea that caster has impact on crossweights under cornering.

mazdaspeed7

Im really glad I read that. I knew caster affected the "weight" on the steering wheel, but didnt know if affected stability. That would explain why my FC with p/s rack converted to manual feels really nice, and not too heavy, but my car is quite twitchy, especially at 80+ mph.

HWO

same here, even at dawdle speed the steering is sweet, when i'm stationary its fairly heavy, my steering wheel is only 11 inch diamter though hehehe

peejay

It's not just an idea, it's been proven.

http://www.ground-control.com/gctalk5.htm