already ordered and installed the rear toelinks with lockout and they are awesome!

SPL said this to me...


Number 1 I would replace the tension rod, which is where you have that BMR lower control arm bushing, but if you are planning on getting the Vorshlag camber plates, you MAY be able to get the castor you need, but it only has a few settings for castor, it is not on a slider like camber.

Otherwise, in order of importance
1. Front lower control arm - Roll center correction and additional camber
2. Tension Rod - Castor adjustment, elimination of play in bearing up front
3. Rear Upper Camber Arm - More rear camber

how much more do you need? 1.7 should be plenty, no? Does he have recommendations as to camber/caster/toe that his parts help achieve?

I have the rear toe arms installed and have -2* camber in the rear with 0.15* total toe in. I also have the Vorshlag camber plates set to -3* camber. At first I was at the stock caster setting (7*) but I changed to the only other caster setting on the Vorshlag plates (9*).With the caster at 9* I can see the wheel sitting slightly closer to the rear of the wheel well. SO the tension rods would be good if you wanted more caster and you could center the wheel more. The upper rear camber arm, imo, is only needed if you want to go more extreme with the negative camber or want to use a lockout on the lower control arm.

Just to clarify, if your F wheel moved visibly to the rear, this would decrease caster, correct?

yea i have the toe rods with lockout already and looking at the camber plates but i have aftermarket struts so not sure if they will work

No, the other way. Positive caster is the rearward tilt of the steering axis. Because the wheel centerline is above the lower ball joint, the caster change can cause the wheel location to change. How much it changes varies based on amount of caster change and physical location of the lower ball joint and the wheel center.

Yes, maybe. If the bottom of the tire, where it touches the ground, moves to the rear, yes, caster will decrease.

But, If the top of the tire moves to the rear, then caster will increase.

Understood. Yet it seems counterintuitive to me, that a wheel would move rearward when caster is increased.
Perhaps a key here is where such movement would be measured. A bit surprised, that's all.

Hmmm....not sure how you move a top (or a bottom) of a round object without automatically affecting both, as a relationship between top and bottom is always 0 degrees (on a round object).

In any case, if the wheel did move rearward, presumably this would have an affect on F to R weight distribution (and not in a positive way imo).

All in all, interesting discussion. Apart from rear toe part, not quite sure how all these $ translate into faster pace, or better tire wear, etc. Cheers!

I could have detailed it a bit better, for sure. The tire goes where the knuckle places it. And it's the knuckle that tilts. Given enough change, the relationship of the tire, within the fender, will start to change. Small changes might not be visible. I think the caster will change faster by moving the radius rod vs moving the upper strut mount. Caster is not a measurement of any of the tire's geometry, but of suspension geometry. As seen in the picture above, the caster line does not necessarily intersect at the contact patch, depending more or less on the amount of caster. On my Gen5, I once had Moreno camber plates that would allow me to add positive caster by rotating the plate. With the Moreno design I would have to give up max negative camber to get more positive caster, but never the less, more positive caster was obtainable at the top of the strut. Atleast with the Vorshlag Gen6 camber plates, as in Scargoes case, there is no compromise, you can have max camber and more caster.

Here is my 1LE, +7.2* top pic, +9.0* bottom. notice the gap at the front of the tire to the fender edge. The tire is pulled forward with the +9.0*. All of my caster gain is done at the radius rod (Gen6 ZLE), but if I was able to add more at the top, again, as in Scargoes case, the top of the knuckle would tilt more, pulling the tire rearward.

Attachment 1049874

Attachment 1049875

In reality, the movement was less that 5mm. It is visually perceptible if you look hard enough. The average person would likely not notice. But the positives from 2* more caster outweigh the shift in weight distribution. As for the rear toe links, I did them so I could make sure I attained the toe setting I wanted at the camber setting I wanted. And with the lockout, no replacing rear toe adj bolts every alignment.

Thanks guys, yep that makes sense now.
And yep, what the bottom pic shows was my expectation hence my original reaction. NB Obviously, i get the benefit of the rear toe link.
Not sure i would conclude that an increase in caster automatically negates a weight ratio difference, but i suspect it all depends on what one is after.
Thanks for the added explanations - appreciate it!
Cheers!

Increased caster will help with return to center but the most important thing, especially on a strut car that loses camber as the suspension compresses, is the camber gain when turning. 2* doesn't net you camber gain vs stock but reduces the amount of camber lost in corner. I also noticed a decrease in the amount of understeer on tight corners at the autocross. I haven't noticed any drawback to applying power like this but I also have the alternate eLSD tune.