caster mod limit
 

hi all
im going to put a plate between the front lower control arm and the rear arm mount to increase the caster. where people do the free caster mod
iv heard "you cant get enough caster" a few tines now

how big of a plate can i install here?

ill be using replacement bolts the right length and strength

can i install 20mm plates here?

cheers
josh

http://forums.nasioc.com/forums/show....php?t=1900666

And another if you're running coilovers. But recently ive heard mixed feelings regards this and advised to use Proper Caster top mounts to retain the shock static.

http://forums.nasioc.com/forums/show....php?t=1896023

i don't run coil overs but i am considering installing camber plates and fitting them sideways for further caster adjustment.

6mm plate seems to be the norm

I reversed the pin then used 6mm spacers, I've got adjustable top mounts, swapped side for side and set for max castor and got just over 6 degrees. I've been told that's enough.

How does it feel compared to standard

At the same time as doing the castor mods I fitted the roll centre correction kit, so lowered the car a bit (about 40mm) had geo. set up and fitted new sticky tyres, the difference was like night and day, miles better, but what difference just the castor mods made I don't really know. That's the trouble with doing several mods at once.

caster us supposed to make a big difference in front end grip. its not to hard to do ether

your setup sounds similar to what im going for

I see. Thanks

So what are the drawbacks as i assume subaru would have done it from the factory if it was so simple?

thats a good point actually
i dont know why they didnt put more in. there 3.5 deg as standard.

bmw and mercs tend to have a lot of caster from factory

Im gonna give it a try and see how it pans out.

Cheers

They did , on the Spec C . ALK will give you more caster too. It makes the steering feel very heavy for everyday driving. Don't forget It's a road car and plenty of space have been left to tune it the way you like it. That's the beauty about it. If you want a sharp handling car get the most focused model as a base , Spec C , RA etc.

The factory setting will give the safest handling for an average driver in any condition ie cornering under power, braking into a corner emergency stops etc.

Adding more caster will affect the camber angle when the steering is turned, the outside wheel will gain negative camber.

The 'drawbacks' of this could be an over steering car just when you don't need it.
Any suspension improvement will compromise something in the suspension in another area, subaru will have found the happy medium for most grip and safest handling.

I'm running a fair amount of caster on my 05 STI and another reason for not running "too much" that hasn't been mentioned is the limitations of the wheel arches!

At might rideheight and caster, I destroyed my front arch linings during my last trackday. I'm doing a load of work to the car over winter but before my first spring trackday I'll be going back for geo, and will be looking to either reel in the caster a bit or raise ride height a bit (or a combination of the two).

My Setup is:

Whiteline ALK
Chevron custom control arms
KW V3 Coilovers
Whiteline Max-C camber/caster plates

The Plates are actually set in such a way that they provide the least caster, so I could get even more than I'm currently running! (just under 7 degrees IIRC).

Ride hight is critical on these cars . Dont lower it too much as it will mess up the handling. The arch clearance is important but not so much same time if it sits at the right hight. The turning angle improves with the above mods as correction angle. The amount of lock is shortened. If that makes sense. Whiteline caster plates are great as the rest of your components Fonzey.

Five is enough, 6 is fantastic.

I'll say it as long as it takes to get the message home, on a McPherson Strut car DON'T LOWER IT TOO FAR! FFS. This is not rocket science. The Roll centre determines roll torgue from it's position with the Centre of Gravity. On a McPherson car, for every inch you lower it, the CoG drops that inch but the Roll centre drops further...much further.

I run standard ride height for a reason, and can corner probably better than you as a result. I don't get much body roll, yet I have a supple and complient ride. Castor is a GOOD THING. But like all things, too much is not good for you.

To Markyscoob, how much is too much?

Standard gc wheel centre to arch front 370mm rear 365mm
P1 f350 r335
wr99 f340 r330
I'd go max, depending on spring rate, f335 r330

Kyb Agx - no more than 38mm lower than standard.

HTH

this seems resonable. frankly im not really surprised if the car handled worse if lowered more than this. could probably see by eye that it would be worse