how much caster to run?
 

getting an alignment soon and have my preffered settings pretty set expect for the caster. here is what i had in mind.


Front caster 6.45’
Front camber -1’ to -2’
Front toe 0

Rear camber -2’ to -2.5’
Rear toe-in .15 inch

the UK specs have caster set as above yet ive heard of people running it around 5.5 degrees. i understand how caster works but am unsure how it would effect handling/wear going with one or the other. any input/experience with either/ or explanations would be greatly appreciated. its not a track car but is a DD that doesnt see too many miles a week but tire wear to performance aspect is what im concerned about. thank you in advance :hello:

More caster is good in that when the wheel is turned in a corner, it creates additional negative camber for the outside tire, while reducing the negative camber at the inside wheel, both good things which lead to increased grip from your front tires.

However, caster also affects the self-aligning torque on the wheel since it increases mechanical trail (the distance of the center of the tire contact patch behind where the steering axis meets the ground). Self aligning torque is a function of the lateral force the tire is developing times the total trail (mechanical + pneumatic). Part of driving a car near the limit involves the ability to 'feel' when the tire's grip has passed it's maximum. If you have too much caster (too much trail), you won't be able to 'feel' the grip of the tires as easily, which is bad. That said, I have absolutely no idea how much caster is too much for our cars, and even then, I imagine it also comes down to driver preference.

But, for a street car/DD, I don't think it is really worth worrying about. I'd just set it and drive it. I don't imagine it will have much if any effect on tire wear.

usually people put max caster (which is ~6.5).
last time i went for a lower caster exactly for the reason of more feel.
IIRC i've put 5.5.
it definitely feels very different.
a bit veird at the beginning.
definitely lihgter.
i like light but communicating :tipwink:

hmmm interesting. not sure which i should go for yet. i may see what it is set at right now before they adjust it and go from there. anymore people who would like to share their caster settings and preferences are greatly appreciated

I'm running 7.5deg. I like the on center feel and obviously don't mind added grip. If your only running -1-2 deg camber I'd max out the caster.

I am not sure off the top of my head how much I am running but I asked for the maximum available while still achieving my desired camber when getting my alignment. I greatly prefer the heavy steering.

I've always run high caster but I'm going to give 4.5 degrees a try so I can relax my grip a little in the corners where you really need the steering feedback.

On a stock setup (meaning no aftermarket ball joints) I would max the camber first, and then max the castor. Neither will come anywhere near the "too much" zone on a stock S2000. But I wouldn't sacrifice camber to get more castor. Hope that makes sense.

If I remember correctly on my car the difference between max caster and min was like .2 or .3 degrees camber change. I don't think it matters but this was with J's S1.
I run 5.5-6 caster

What's your conclusion?