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caster?

Old 03-26-08, 12:29 PM
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caster?

so ive been looking, and i always thought more caster was just better. and the non-fd's dont have much adjustment there either.

i noticed the other day that on the 1st gens stock caster is about 4 degrees, but the comp spec is 3. isnt more better?

this pertains to everyone, the FD can get lots more caster than anything else

so what does caster do that we dont want much?
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Old 03-26-08, 12:59 PM
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More caster = more steering resistance for one, since the wheels want to self-center more as you add caster.

other than that, I'm not quite sure.
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Old 03-26-08, 02:23 PM
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I haven't been able to find any negative affects of added caster besides the heavier steering. I maxed mine out and like the extra stability and steering resistance. According to howard more caster = more weight transfer.

caster in larger amounts is bad. it is used as a band aid in many front wheel drive cars in attempt to fight torque steer. here's a fun thing to do. in most any front wheel drive car turn the steering wheel lock to lock and "watch what happens." you will note that the large amount of caster raises one corner of the car at full lock and drops the other front corner. this transfers weight. not good. stay w a modest amount of equal caster.
Edit: More info from the howard coleman thread
(Reguarding an FD)
I've played around with different Caster settings on my car last year. I started out near 7 degrees (previous owner's setup) and the steering felt a bit slow. Changed it to 6 degrees and it really livened it up. As it got get closer to 5 degrees the car wants to tram line a bit more and is a bit too lively for my preference (mostly a street car).
Too much caster can actually reduce weight on the inside rear, which isn't a good thing for traction.

Last edited by KhanArtisT; 03-26-08 at 02:34 PM.
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Old 03-26-08, 04:02 PM
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Caster is also referred to as "the poor man's negative camber". The amount you like is really dependent upon suspension design and setup.
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Old 03-26-08, 05:10 PM
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My take on caster:

If you increase caster it will decrease the turning radius but increase oversteer in fast corners.

If You decrese caster it will increase understeer and high speed corner stability.

I might remember it wrong. could be the other way around
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Old 03-26-08, 09:50 PM
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With more caster you end up with more camber gain when you turn the wheel. You can play with this balance to keep the wheel at the right angle to the road as the car leans with the wheels turned.
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Old 03-27-08, 05:08 AM
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On an FC?
Don't **** with it...

Local guy setting up a track car tried to mimic the S13 supension geometry...
It runs over 10-degrees of castor.
He said the FC handling like **** when he tried like 13-degrees of caster.

I'd figure you'd want minimum caster just to get the car to respond faster to steering inputs?


-Ted
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Old 03-27-08, 07:15 AM
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Merc's massive castor?

I've seen many Merc's (Mercedes not Mercury's) here down under with what looks like high castor creating massive neg camber when they turn at slow speed to park - is this the case?
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Old 03-27-08, 08:03 AM
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Originally Posted by sledgie View Post
I've seen many Merc's (Mercedes not Mercury's) here down under with what looks like high castor creating massive neg camber when they turn at slow speed to park - is this the case?
Probably. It takes power steering to make it driveable most times. I would think the shitty handling feel on an FC would come from the fact that the castor effect wants to straighten the wheels out and its a bitch to just hold the car in a turn. I've thought about running an electric power steering pump on my car just to be able to play with this and not need arms like Popeye.
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Old 03-27-08, 02:36 PM
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Originally Posted by sledgie View Post
I've seen many Merc's (Mercedes not Mercury's) here down under with what looks like high castor creating massive neg camber when they turn at slow speed to park - is this the case?
thats kind of why i asked, my bmw e30 has 9 degrees of caster stock, this and the ballast they call and engine are why it feels great on the freeway, compared to the fc anyways
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