You make a great point. Of the comments posted here, the main objectors who have technical knowledge (opposed to the sheep who think the world will end we'll all die) all seem to be selling the aftermarket "approved" Kits.
No disrespect to any of them of course, they have a business to run.
What grinds my gears is the 'new car tax' premium we are being asked to pay for these kits.
Correct me if I'm wrong but the Brembo STi brake packages offered on the WRX STi and BRZ Ts look the same because the caliper bodies are the same but are specific to each car because of a different size bore for a different size piston.
Prospeed in Oz will sell Brembo STi kits f/r for AUD3500. They don't state it but I imagine these are off the WRX STi (GV/GR) and are not the BRZ TS Brembo kits that are for sale on Japanparts for the astronomical amount NZD6300 for the kit - plus shipping plus duty.
The difference in the parts? Sweet fuck all.
This is called TAKING THE PISS.
Similarly, my mechanic can build a new complete front/rear AP BBK for 'older cars" for NZD2500. The cost to me if I buy the 'factory kit' from the local distributor is NZD8500. WTF?
All the vendors on here seem to want us to believe they care about our safety and driving experience more than they care about the margins they make on these new products.
Why not ask Brembo/AP to drop the 'new car tax' on calipers that are the best part of 10 years old and are really only different in terms of piston sizes?
I expect the response will be "R&D costs....blah blah
"
If the mathematical templates for brakes on other websites are reasonably accurate, I imagine Brembo/ AP would simply establish requirements by plugging the cars metrics into their computers, test a prototype or three, then bam, its on the market at 3 times the price of the caliper kit for the last flavor of the month. Lets face it, if the WRX STi caliper works on that car, its going to work on the BRZ and look really good while doing it.
Feel free to tell me I'm wrong.