Project 4Runner TRD Pro: CSF Radiator, MBRP Exhaust, Westin Bumper Installed

Photography: Darrien Craven

  • Pit+Paddock and CSF are teaming up to build a 2022 Toyota 4Runner TRD Pro geared for overlanding and off-road adventures.
  • The second week of installs is complete, which consisted of a CSF radiator, MBRP exhaust, Westin front bumper, and a Superwinch winch.
  • The final stage of the build will debut at Pit+Paddock’s Cars+Coffee: Overland Edition event to be held at CSF’s Rancho Cucamonga headquarters on May 1.

Over the last two weeks, we have introduced you to our latest project vehicle – this 2022 Toyota 4Runner TRD Pro in Lime Rush green. Together with our collaboration partner, CSF, the plan is to build the 4Runner into a more serious off-road rig with the goal of debuting the final look at a special Pit+Paddock Cars+Coffee: Overland Edition pop-up event at CSF headquarters in Rancho Cucamonga, California. So far, we’ve successfully added basic bolt-on upgrades such as an Airaid intake, throttle body spacer, and Pedal Commander controller (you can read all about it here). We’ve made some solid headway this week by installing a CSF radiator, Westin front bumper, and Superwinch winch.


If you’re adding more power to your engine, it’s also good practice to upgrade your cooling system. Our 4Runner will have a high-performance intake and exhaust. We understand both those mods don’t inherently generate extra heat; however, everything gets compounded under heavy engine stress. Plus, we also plan to step up to a supercharger in the near future, so updating the cooling system early in the process makes a lot of sense.

Most people don’t know that off-roading can put a tremendous amount of strain on an engine because you are moving at a much slower pace, whether traversing across trails or climbing up hills. Typically, a vehicle under a similar amount of engine stress would be moving at a relatively higher speed, so a radiator with extra cooling capacity is extremely important to cope with the additional heat.

The CSF radiator for the 5th-gen 4Runner uses a 42mm thick two-row core versus the OEM 22mm single-row core. It doesn’t take a rocket scientist to see how much more cooling this offers! Aluminum side tanks provide extra durability compared to the OEM plastic tanks, which are prone to crack over time. The CSF unit also includes a higher pressure 1.4-bar cap which raises the boiling point of our coolant, keeping the system from boiling over under high heat.

We’ve run CSF radiators on older Integra and WRX project cars and can say the quality really lives up to the reputation. Installation was an absolute breeze as well. The radiator is designed to bolt in the same exact way as the OEM unit. The most tedious part is draining and refilling the coolant.

On a side note, our local Toyota dealership warned us that the OEM radiator is a weak spot on 4Runners and one of the first things to fail. We’re glad we upgraded it at this stage.


There are countless reasons why people upgrade their exhaust system. Typically, it’s for the louder exhaust note and power gains from a more efficient system. In the off-road world, there’s also an added benefit on some aftermarket systems that’s often overlooked: ground clearance. Vehicle manufacturers don’t typically design their SUVs with serious off-roading in mind, so companies like MBRP design systems geared towards such activities.

We decided on its Pro Series high-clearance turn-down cat-back exhaust for this build. The 304 stainless steel construction gives us extra corrosion resistance from all the extra mud and grime we’ll be kicking up. The high-clearance turn down tucks the exhaust tip higher up under the rear of the 4Runner. This will keep us from crushing or damaging what’s normally the most exposed exhaust section. The muffler is also much smaller than the OEM unit giving us extra clearance in the middle of the truck.

Performance should see a nice bump with a freer-flowing muffler and 2.5-inch diameter tubing as opposed to the stock 2.25-inch system. The improved airflow will complement the Airaid intake we added last week.

Installation for the MBRP exhaust was a breeze. Because the truck is so new, all the original bolts came out very easily, and the system went in without a hitch. The exhaust note is perfect for our taste. Definitely a noticeable increase in sound but not overbearing and gives the 4.0-liter V6 a nice rumble at lower RPMs.


In the sports car world, front bumpers are usually swapped out for better aerodynamics or aesthetic purposes, which generally don’t offer any practical benefits. In off-road, aftermarket exterior parts are all about function over form. We decided to go with the Westin Pro Series front bumper, mainly for its strong durability, ability to achieve better approach angles, and safer winching and recovery. These off-road-type bumpers bolt to the truck’s frame, making them incredibly concrete. This also allows the option to mount accessories like a winch (up to 12,000 pounds in this case) to it without ripping the bumper off. Additional features include a 20-inch LED light bar cutout, corrosion-resistant coating, and it even has provisions for factory parking sensors. We tacked on Westin’s round bull bar for both styling and a little extra grill protection.

As for the install of the front bumper, we’d love to sugar coat this, but this was one of the harder jobs to date on the 4Runner build. It’s not terribly complicated but is rather labor-intensive. Cutting the factory bumper to accommodate the Westin was stressful, but you know there’s no going back once you make that first cut. After the new bumper is bolted in place of the factory crash bar, you can really get a feel for how solid it is.

We know this is a very functional modification, but we still can’t get over how cool it looks while still retaining the factory bumper. It really gives the 4Runner an extra menacing and rugged appearance!

Note: The torque spec on these bolts is 82 ft-lb, which is missing from the instructions.


People may tell you that you can off-road without a winch, but you probably shouldn’t. A winch is a very important tool to have when you’re off the beaten path and get your truck stuck. For our TRD Pro, we selected the Superwinch SX10SR. Rated at 10,000 pounds, this 5.5hp unit is more than enough to haul the 4Runner out of any ditch or ravine it might get stuck in.

If you are shopping for your own winch, you want to make sure it has a few key features that our Superwinch has. It should be waterproof, dustproof, and compatible with a 12V DC power supply (the voltage and current type of an automobile). We decided to go with the synthetic cable version for the weight savings and little extra safety if it ever snaps.

Superwinch is owned by Westin, so as you can imagine, the front bumper has been perfectly designed for this winch, with the installation and wiring process being completely painless.

Stay tuned for the third part of our build next week as we dive into the lighting and install more off-road necessities on our Lime Rush 4Runner TRD Pro!