The fan-mounted shroud attaches to the radiator with six M5 bolts. Now the radiator was ready to be installed.
The Billy Johnson Racing V-mount radiator attaches to the car’s frame rail with 1/8” thick aluminum that doubles as a mounting bracket and a duct that prevents air from finding a path of least resistance, and forcing the air through the radiator. The bracket bolts to the top of the frame rail with two bolts and then the radiator is mounted to the bracket with three bolts.
The radiator is placed between the frame rails with the top bracket mounting bolts installed, since they are not accessible once the radiator is in the car.
After bolting the bracket to the frame rail, the bottom of the radiator swings up and the bottom four bolts can be installed to bolt the radiator to the bracket. We added foam strips to seal the radiator to the intercooler to make this V-mount a proper, air-tight installation.
The radiator inlet was positioned to be directly over the factory bolt-in factory brace.
Foam strips were also added between the radiator end tanks and the mounting brackets to force all of the air the enters the front bumper through the radiator. Creating an “airbox” that seals the radiator and intercooler to the front bumper is a fundamental aspect of making a cooling system efficient, which is often overlooked in most builds. There should not be any paths for the air to bypass or go around the radiator or intercooler.
The 56mm thick BJR radiator looks massive from this angle. We can see the lower mounting bolt that attaches the radiator to the integrated duct/mount. The RX8 A/C condenser lined up perfectly with the front bumper opening, and the side duct seals the radiator and intercooler to the front bumper, forcing all of the air that enters the bumper through the coolers.
5 comments
Fantastic update and all the custom work on the cooling system is so cool to read about. I am patiently waiting to see this thing finally unleash some HP!
Technically, you should have a ‘blade’ that bifurcates upper, and lower flows at the start of the duct. If you modeled this in CFD, there would be obvious turbulence that could easily be avoided.
Cheers.
Was about to comment the same thing.
Also, the air out of the IC needs to go somewhere… I don’t remember what the hood looks like for this project, but a proper vent with gurney flap and ducting would do wonders at speed.
Can’t wait to read the next articles.
It’s not that crucial to bifurcate the ducting. Many morern OEM cars don’t separate the inlet ducting of a common duct/plenum that feeds multiple heat exchangers because airflow is not laminar in the ducting and the important aspect here is creating a pressure differential across the heat exchangers. Proper ducting that seals the air from the front bumper to the heat exchanger creates a high pressure area on the front side of heat exchangers in the V-mount setup (or “L”-mount in many OEM applications) when using a common plenum (or air box, or radiator ducting).
I am currently in my FD build and would love to have one of these radiators, could y’all please guide me in the right direction to purchase one if they are available. I left a message on the BJR site to no avail. HELP…..someone??