Arch

iTrader: (59)

It's a valid question Andy unfortunately not being the designer of the hubs I don't have the answer. I would doubt a standard Impreza or one with a quick rack will have a 100% Ackerman figure. I know this was mentioned in one of the emails I had and it was something that would obviously limit the amount a steering input could be quickened but from my limited knowledge of the subject I doubt very much that a 10% change would cause any issues unless you have some figures?
I will however ask the question.

Arch

iTrader: (59)

Once the hub is designed the main cost is in the material and production so its not really a case of reducing the changes to make them cheaper, the cost is pretty much dictated by the cost of the raw materials and the production process. I know Spitfire have cut there margin to the bone to try and make it work but there is only so much that can be done in terms of cost.
But ist a question I will definitely ask but I am sure you can see every uprated parameter you remove the reason for doing it diminishes and the cost v gain decreases.

AS Performance

iTrader: (4)

without peeing on Arch's thread then view the "other" thread if your not into the Billet cost..........

JGlanzaV

iTrader: (3)

Yes this is what I thought.

Its a real shame, but I just cant justify it. As much as I would love to....

If this was 6 months ago before I got some 5x114 hubs machined to fit my classic then it would have been a different story...

Yes been meaning to drop you a message about it!

Arch

iTrader: (59)

No problem Alyn were looking at two different options

2pot

iTrader: (3)

By raising the bearing position 25mm-33mm - is that optimising a particular range of front ride heights?

Maximisation of the caster - more than 7deg? Or, trying to achieve 6-7deg?

Arch

iTrader: (59)

The bearing height change is to adjust for the changed roll centre when the cars are lowered. The reason for the quoted 25mm -33mm is the exact amount hasn't been finalised but there is a finite amount it can be moved due to the position of the bearing pack relative to the strut mount.

Everything conflicts against each other as you try to achieve all the parametres but the logic is to get as near to 6 deg as possible so that it may be possible to get the 6 deg without having to modify the lower arm, that would be a combination of built in castor on the hub and possibly some adjustment at the strut top.

Optical

Instead of (or as well as) raising the hub mounting location, you could extend the ball joint mount further down which would also raise the roll centre without running into a mechanical limit.

I also recommend reviewing this analysis of the subaru ackerman angle
http://blog.perrinperformance.com/50/

Optical

Also how are you going to affect caster with the upright? The caster angle is defined by the position of the swing arm bearing and the bearing at the top of the strut. The upright just bolts between and doesnt change either of these points?