steering knuckles
 

I prefer the looks of the GR but I want the aluminum knuckles from the BRZ.

Are they interchangeable? Geometry the same?

Any thoughts as to why the difference?

I believe Savage Geese said they are the same and are easily swappable if you're so inclined.

Only $340 each from Subaru! lol
https://parts.subaru.com/p/Subaru_20...8311CC010.html

What's the final verdict on this ?

Did Toyota use the steel ones to save cost or because they are stiffer than the aluminum ones (may give better steering feel)

I believe Toyota SAYS they are stiffer, and my guess it is technically a true statement. But is a person actual going to notice a difference in stiffness of the knuckle considering you've got rubber bushings, tires, and coil springs all moving about? Hell no.

Some possibility not considered is that Subaru and Toyota started with some baseline and then it was Subaru that decided to make aluminum knuckles independent of Toyotas engineering team.

They will lessen the un-sprung weight as well. I assume there are published weights somewhere of each.

Be aware that the aluminum knuckles are not compatible with some BBKs on the market.
Otherwise should swap fine.
Minimal weight savings, probably not noticable.
A lightweight battery is probably better value for money.

A quick search reveals this:

According to reports of Toyotas 3 month tuning delay, these knuckles were changed to the old ones at the very last minute.

There is a chance it was done to improve the balance of the car at the limit, Toyota was (again according to reports at the time) really struggling with some of the tuning.

I'd wait for someone to check it out.

Its probably cheaper to just get the GR86 front facia for your BRZ. :)

Interesting, if we keep in mind the front damper tuning is not the same, it could be that the heavier stiffer kuckles were a better match for what they wanted to achieve.

I don't mind it at all they will probably do some additional tuning and changes as the year go on.

It's a cheaper part and more durable. Most likely nothing to do with any kind of performance. Aluminum provides better NVH as well as less unsprung weight. But balance and feel? That sounds like a marketing department not an engineer.

Cast iron is stiffer. Would you notice? I don't know, would you notice the rear swaybar being mounted to the subframe versus the body? Would you notice the difference between a 18.3mm hollow swaybar versus a 18mm solid one? Would you notice putting the 18mm bar bushings on the 18.3mm bar to get more squish in the rubber and more stiffness?

The aluminium knuckles by themselves are probably not better or worse, they probably don't make that huge of a difference in the overall setup.

I'd spend my money elsewhere on things that would make more of a difference.