https://www.nismo.co.jp/news_list/20...ash/20022.html

Weight: 1.9kg vs 5.9kg stock
Price: 250,000jpy
Reduce oversteer and understeer
Link above provides details of this.
This is taken from official NISMO website(not my personal opinion).
ドライカーボン化することで軽量化を実現するとともに、高い剛性と適度なしなやかさを兼ね備える特性によって、コーナー進入時の アンダーステア、旋回～コーナー出口のオーバーステアを軽減させます。
Google translate(not perfect)-
By using dry carbon, weight reduction is achieved, and understeer when entering a corner and oversteer from turning to corner exit are reduced by the characteristics that combine high rigidity and moderate suppleness.

 

 

The FM platform is already stiff, but stiffening the front end will not reduce oversteer.

 

Yup. Matter of fact, IF a strut bar did increase front roll stiffness, exactly the opposite would happen.... increasing understeer.

But, strut bars do nothing to or for roll stiffness and therefore, no change in steering attitude.

Strut bars ARE highly beneficial to steering however. In keeping the strut towers in line and with no torque effect on them, this aids steering input precision at the extreme levels, particularly in race/autocross applications. Not a lot of noticeable flex in street situations so adding a carbon fiber unit doesn't do a lot but for the pocketbook and oooahh points.