Project Lexus IS-F, Improving the ride via the brakes with FIGS Engineering


The front rotors are also a two piece design. The FIGS rotors are fully machined on all surfaces.  This is a big plus because it ensures better balance.  Notice that the rotors are slotted instead of drilled like the stock rotors.  Slotted rotors are much less likely to crack than drilled.  If you look carefully you can see that the slots on the Fig's rotors are vented with milled grooves.  Fig's calls this design an Open Slot.  The open slot is siad to reduce thermal stress on the rotor making it less likely to crack.  It also self cleans and vents much better than a typical slotted rotor.  The grooves are rounded so as not to cause stress risers where cracks can form.  Hopefully these rotors will prove to be crack resistant.
Like the rear, the front rotors are vane vented. The iron friction ring is e-coated on all non friction areas to prevent rust from looking ugly and dripping out of the rotor to stain your wheels, a nice touch.  The hub hole is machined to very tight specs so the rotor positively indexes on the hub.  This also reduces potential vibrations.
The FIGS rotor's fastener system is unique.  It is a semi floating system.  Normally racing rotors are bolted together with shoulder bolts that allow around 0.010-0.012″ of movement between the hat and rotor.  This float helps reduce a rotor's tendency to distort in a cone shape under hard use.  The drawback is that it is noisy and rattles when street driven.  Some companies use spring washers and other tricks to reduce the noise but some noise is usually still audible.  Because of this many street two piece rotors are solidly bolted together which nullifies some of the potential performance advantages that two piece rotors have to offer.  The FIGS rotor uses shoulder bolts but they are close tolerance so the rotor can move but with very little freeplay.  These flat nuts index on the hats and reduce freeplay while still allowing constrained movement as well.  As a result you have some of the advantages of free floating rotors without the rattles.
Like the rear rotors, the alloy hat only touches the rotor in a few places through tabs to reduce heat transfer to the hubs.  You can also see how unobstructed the airflow is to the friction ring.  The alloy hats are hard anodized.
The Project Mu rotors were closely machined to the hubs as well so we had to use a 6mm bolt to get them off the hubs.
The IS-F has big brakes and one piece big iron rotors are heavy!  The rear rotors were 18 lbs each and the fronts a whopping 26 lbs each!

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