We often get asked what is the correct orientation when installing directional brake rotors. The correct orientation of the vanes is a subject often debated. I wanted to take this opportunity to clarify it with help from my buddy Martin from Girodisc.
From Girodisc's website: For maximum airflow and superior cooling, the Girodisc system uses curved vanes. For a curved vane internally vented disc, the geometry of the vanes dictates the direction of rotation. A curved vane disc must be installed with the vanes running back from the inside to outside diameters in the direction of rotation. Your discs will come with labels indicating their correct placement on the vehicle. Orienting the disc in this manner creates a centrifugal pump. The rotation of the disc causes air to be pumped from the center of the disc, through the vanes, and out through the outside diameter of the disc. This greatly enhances the disc’s ability to dissipate heat. Discs installed backwards have very limited cooling.
Many clients wonder if their brakes are good enough. The truth is that most stock Lotus will run fine on track with the stock brakes. The advantage of our lightweight cars is that we don't actually generate that much heat when braking properly. We've tested brakes temps and posted about it last year: see brake temp post. Of course as drivers get faster they realize that the stock pads lack the initial bite they need to be confident when out braking those pesky GT3s. Or when they have burned through their original rotors they start looking for alternatives.
Our discNOIRs, ULTRAdiscs & CUPdiscs all come from Girodisc and therefore use curved vanes to maximize the cooling potential. Now that cars are running higher levels of power, with slicks and serious downforce, we are starting to see more heat in the brakes. Running properly vented rotors, better pads and fresh brake fluid usually is enough to keep a modified Lotus stopping on a dime - repeatedly. We use our AP Rotor paint to see how hot they are really getting - before jumping to conclusions.
But for those who need more, we have more BBK solutions coming.....we are now testing a bracket that relocates a stock front caliper to the rear - especially tasty for clients running our 308BBK or a Lotus Sport upgrade. Stay tuned as we are still mental as ever...