Hey guys,
My name is Chris. I have owned a few 4Runners in my time and created the original bumper mounts I used to sell on here for 4th gens. I have been a part of the Cali Raised team since last year. I do the design and engineering for Cali Raised and Jake just showed me this thread.
I wanted to shed some light on the design and testing of these mounts and the air flow as far as I understand it.
These mounts were completely redesigned to create a much stronger and robust mount while also reducing some weight and allowing you to install a winch bumper. Originally these mounts bolted to the factory aluminum cross bar. This works well but is hinders the ability to add in a low profile winch bumper like @c4_fabrication makes or a full plate bumper, one has to go. With this new design the mounts bolt to the core support in two places and allow for a mount that is supported from multiple angles, creating a much stronger mount. It also allows you to replace the aluminum cross bar with most any bumper and still mount LED's in the grill.
As far as air flow goes, this is something that has been tested extensively by a few people we invited to help us with product testing. While you may envision wind tunnels and simulations, the best testing is typically real world product testing. Because of previous mounts being used on many 4Runners out there, we know that a single LED works well with the factory 4Runner cooling system. Still we wanted to ensure the new design worked well. Our chief tester is the owner of an overland group in Southern California who has a very robust 4Runner with lots of additional weight and who runs a lot of trails and uses his 4Runner more than most. He has been running this mounting and LED setup for 5 months now with zero temperature issues. We did some robust initial testing and continue to review cooling temperatures and vehicle performance over time. His 4Runner is doing well and we are about to be doing further testing with him and some bigger bumpers and higher vehicle loads.
Additionally I wanted to touch a little more on Toyota cooling systems. We have contacts with Toyota engineers who also use our products and assist us with design as well as being a member of SEMA which grants us access to manufacturing information about these vehicles. The cooling systems in modern day vehicles are nothing like those of previous generations. With modern fan and cooling technology auto manufactures have been able to create extremely efficient cooling systems that no longer require huge amounts of moving air to enter the grill of the vehicle. Instead they utilize highly efficient electric fans to pull air across the radiator to cool vehicles. I simple explanation is to look at modern vehicles on the road. Besides Toyota using the 4Runner grill as a styling cue, you will notice that most vehicles have much smaller grill openings than ever before. Many have large grills but under close investigation you will see that large portions are blocked. Ford recently on their F150 line introduced fins that actually block radiator flow during certain driving conditions that actually eliminate air flow completely. Why do they do this, simple, MPG's. In modern engineering we have learned that air flow through the grill reduces MPG of vehicles because it acts like an air wall. That is why newer vehicles have air dams and other air directing plastic to move air in and out of the engine bay for better aerodynamics. When installing an LED from us or any company you will more than likely have to remove the air dams in order to install the light. This will have almost no effect on the cooling ability, but may slightly lower MPGs. Our new design, while not made to be a replacement air dam still helps create this effect, reducing the loss of MPGs.
Sorry if this is wordy, but I wanted to share my philosophy on the subject and hopefully answer any questions people have. For those that want to run two LED's we advise that you use common sense. We cannot test or simulate every scenario out there. From our testing of dual LED's the temperatures have also been not effected but we advise caution for those in very hot climates while towing.
If anyone has any specific questions please feel free to shoot me a PM and I will be happy to help where I can. Thanks for reading and thanks for interest in our products!