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

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

By Mike Kojima

In our last edition of Project IS-F, we had gone through our brake system with NS compound pads and slotted rotors from Project Mu, which replaced the stock, well worn OEM Brembo parts.  We were pretty pleased with how the pads had a nice, well, Mu (or coefficient of friction in geek talk) and super low dusting with enough fade resistance so that we never noticed any in the car's daily driving routine.  Please note that Mrs Nerd has been observed driving back from her lunch break rather quickly at times.  She's a teacher so she absolutely can't be late and teachers only get 30 minutes to get some place, order eat and return.

Even with this hard intermittent use, our Project Mu stuff worked well exhibiting minimal wear.  We were pretty happy and since the IS-F comes stock with big Brembos all around we didn't think that our car really needed any more brake.  That is until we got a call from FIGS Engineering offering us a set of their new two piece brake rotors.  We were pretty stoked to hear this news and wanted a set just for looks if not anything else.  Well we did get the rotors, installed them, and found them to be much more than just trick looking.  Read on!

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We know this sounds ricey but half of the reason why we got a set of Fig's Engineering two piece brake rotors was due to looks.  Sitting next to our future Project GT-R, a single piece rotor doesn't visually cut it even with awesome Brembo calipers.  Of course there were many functional reasons for the change as well.  The stock Brembos were pretty noisy.  They squeaked when cold and sometimes even when not cold.  Changing to the Project Mu stuff reduced the squeaking quite a bit but it still annoyed the wife.  Considering that NS Brake pads are formulated not to squeak, but still did, we decided that changing the natural frequency of the brake system might be a cure.  We knew that the FIGS Engineering rotors would be much lighter which might break up some harmonics that could be causing squeak and squeal.

We were really impressed with the engineering of the rear rotor.  Racing Brakes, an American company produce the IS-F rotors exclusively for FIGS Engineering.  The rear rotor  has an iron friction ring and an alloy hat but that's not the total cool part.

The IS-F uses mini brake drums inside the rear rotor as the parking brake.  If the hat was all alloy the parking brake would have to be carefully applied as the shoes would eat the aluminum alive.  The FIGS Engineering rotor has an iron liner pressed into the hat to act as a friction surface for the brake shoes.  This is really cool!

The friction ring of the rotor is made of spherical iron which is known for its high carbon content and ductility.  The carbon in the crystal matrix structure gives the iron good frictional wear and noise properties.  The rotor is vane vented.  The stock Brembo and Project Mu rotors were pillar vented.  Vane venting, although it has less internal surface area than pillar venting is considered to be better for repeated stops due to the cooling capability of air being pumped through the interior of the rotor.

The hat only touches the friction ring through these small tabs and their is plenty of space between the hat and the friction ring.  This reduces heat transfer through the rotors into the hubs and helps airflow through the rotor.  The bolt system of the FIGS rotor is also pretty cool, we will explain that a little later!