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Techline: Your Top 4x4 and Off-Road Questions Answered Here

Posted in How To: Tech Qa on August 23, 2017
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Tacoma Lighting

I just installed a CBI front bumper on my ’17 Toyota Tacoma. It has a slot for a 20-inch lightbar. I don’t want to go too crazy with too many lights, but I wanted to fill the space so that it’s not empty. Who builds the best lightbar for this application? Also, is the sPOD a good way to control the lighting without having to add individual rocker switches?

Maher Boulos
Via email

Aftermarket add-on lighting can be incredibly useful when traveling down rural roads and dark trails at night. There are many different 20-inch LED lightbars available from companies like Baja Designs (bajadesigns.com), KC HiLites (kchilites.com), Rigid (rigidindustries.com), and Vision X (visionxusa.com), among others. Each LED lightbar has different advantages and features. For general off-road use, I’d recommend a combo-type LED lightbar. A combo lightbar will have spot beams in the center to reach out further into the darkness and flood beams on both sides to light up the immediate area around the front of the 4x4.

There are many different ways to install the necessary wiring and switches required to operate your new LED lights. Most 20-inch LED lightbars will draw just under 10 amps, so it’s best to use a relay of some sort. The use of a relay in the system is safer and will keep you from having to run a heavy-gauge wire from the battery, under the dash to a switch, and then out to the LED light. The switch panels and wiring kits from sPOD (4x4spod.com) are a clean way to add auxiliary switches to the center of the overhead console. Vehicle-specific sPOD switch and wiring kits are available for Jeep and Toyota 4x4s, including your ’17 Tacoma. The sPOD Tacoma kit requires that your truck has the factory sunglass holder for placement of the switch panel. All other mounting brackets and hardware are included.

Pentastar Power

I've heard that adding a better air intake and muffler doesn’t make much difference on the 3.6L Pentastar V-6 in the ’12 to current Jeep Wrangler. Is this true?

Ronnie Longoria
Via facebook.com/JohnCappa4x4

The actual power and fuel mileage gains provided by the many different aftermarket power adders vary depending on the application. Dollar for dollar, an open-element cold air intake will make the biggest difference in power and fuel economy of any bolt-on power adder. Of course, supercharger and turbo kits increase power output by as much as 100 hp, but they also cost significantly more. The open-element cold air intakes do have downsides though. They are usually not as water resistant as the factory intake system, which includes a plastic airbox. So if deep water and mud are your favorite off-road terrains, then you may want to stick with the factory air intake and maybe consider a snorkel kit from a company such as AEV (aev-conversions.com) or ARB (arbusa.com). Keep in mind that a snorkel kit will generally reduce airflow, while it protects your engine from ingesting water. Another thing to consider is that few filters clean the air as well as the factory paper element. Oiled cotton filters will flow a lot better than paper filter elements, creating more power and increasing fuel economy, but they will allow more dirt particles into the engine than a paper filter element. Aftermarket cold air intakes that utilize synthetic filter media do a great job of filtering out the dirt and provide increased airflow as well.

The OEs spend millions of dollars to try and improve fuel economy and power on nearly every vehicle. Most modern factory exhaust systems are designed to milk every bit of available power and fuel efficiency from a stock engine. The original exhaust system on the Pentastar V-6 is no different. If you do decide to upgrade the exhaust, choose the system based on the sound you like. Many exhaust companies offer videos with sound clips of the aftermarket exhaust installed, some are from both in and outside the vehicle. Now, if you have made other significant modifications to the engine, such as a cam, turbo, or supercharger, an upgraded exhaust will make a big difference. The factory exhaust was never designed for the increased airflow that these products introduce, so opening up the exhaust will enhance the performance that they provide.

Bronco Help

I’m an active-duty Navy guy down in Coronado, California. I've got a ’71 Bronco that I’ve been building for seven years and four deployments. It’s about 98 percent done. I just need to find someone to help me get the last 2 percent completed. It needs some minor fabrication work and some tuning. I’d like to find a shop that actually knows off-road vehicles and not just a regular mechanic. Do you have any suggestions? This truck has completely tapped me out and I’m so close, but so tired of not having a wheeling rig. Any help would be appreciated.

Joe Dawson
Via facebook.com/JohnCappa4x4

Chasing down and fixing those final assembly gremlins can be a hair-pulling experience. Fortunately, you are in an area that is ripe with high-quality fabricators that specialize in desert pre-runners and race trucks. Any of them should have no problem completing minor fab projects on your Bronco. Check out JD Fabrication (jdfabrication.com) in Escondido, California. The shop is not too far from you. The company can do any fabwork you need done and will know someone close by who can do the engine tuning.

Best 35-Inch Tire

I’m looking for your personal opinion. What is the best 35-inch tire for all-around use, other than street use? I don’t plan on hitting snow or ice. I have a lightly modified ’03 Jeep Wrangler Rubicon. Thanks for your input.

Shane Batley
Via facebook.com/JohnCappa4x4

With so many off-road-worthy tires available today it’s extremely difficult to nail down the best all-around tire for a given application. A lot of it depends on driving style, vehicle weight, the terrain you frequent most, air pressure, and more. Personally, I generally steer into the more aggressive tires. Small amounts of mud and even slick wet grass can stop some of the less aggressive all-terrain tires in their tracks. Having said that, I have several favorites for the terrains I find myself in most often. Keep in mind that we don’t get much rain here in California, so mud use is infrequent, but I do make runs into the snow in the mountains occasionally. The BFGoodrich (bfgoodrichtires.com) All-Terrain, General (generaltire.com) Grabber X3, Goodyear (goodyear.com) MT/R, Maxxis (maxxis.com) RAZR, and the new Yokohama (yokohamatire.com) Geolandar G003 mud-terrain tires would be among some of my top choices for all-around use. However, each tire has its pros and cons. There really is no such thing as the “best tire.” It totally depends on how you plan to use it, plus my personal experiences in the terrain I frequent may be different than yours. I suggest you choose a tire with features that match your planned usage. If your trails include a lot of rocks, you might want to steer toward something with three-ply sidewalls for increased puncture resistance. If you hit slick clay-like mud regularly, you should consider a tire with large open voids. Light weight is also something to look for. Lighter tires will allow your 4x4 to accelerate quicker and stop in a shorter distance. A lighter tire and wheel combination will also ride and handle better on- and off-road.

Titan Axle Swap

I am looking for a front axle upgrade for my ’08 Nissan Titan. I have found a rear axle replacement from Currie, which I think is tremendously awesome. It’s a Ford 9-inch and it looks like it bolts up fairly quickly without even undoing the brake lines. Do you know of any front axle replacements for this truck? I would surely sing your praises for such knowledge. Thank you very much!

Ward S. Wood
Via email

Unfortunately, you have run into the problem that many IFS truck owners have been dealing with for decades. The factory independent front suspensions and steering systems found on most modern 4x4s are not up for larger-than-stock tires and off-road abuse. If it’s just the axleshafts you are having trouble with, Rugged Rocks (ruggedrocksoffroad.com) offers heavy-duty RCV replacement halfshafts. They are significantly stronger than the stock halfshafts.

Replacing the entire front IFS axle assembly is a much bigger job that will require cutting, welding, and fabrication. As far as we know, there is no bolt-on solid axle swap for the Nissan Titan. However, WFO Concepts (wfoconcepts.com) is working on a kit to install a solid front axle into a Titan. The kit replaces the IFS and stock rack-and-pinion steering with a solid axle attached to the frame via radius arm suspension, coilover shocks, and a traditional steering box. You can see the progress and what’s involved on the company’s website.

Project Parts Collection

I am looking for some help on building a trail rig with 35- to 38-inch tires. I have a ’95 Chevy TBI unit on a stock intake and a short-block with four-bolt mains (casting number 10243880). I would like to use heads from a different motor (casting number 14102193). Will these two work together?

In terms of the driveline, I have many drivetrain parts including a Dana 44 front axle and a 14-bolt rearend with a disc brake conversion. Both axles have 4.10:1 ratio gears. I also have an SM465 manual transmission and an NP205 transfer case. Is there anything that you would suggest I change with the gear ratio on the axles or transfer case? Also, what truck would you recommend I use to put all this in? I don't have a lot of rocks around so that’s not that big of a deal for me. I plan to drive to the trailhead and not trailer it.

Hunter Sheldon
Via facebook.com/fourwheelermag

Most Chevy engine performance enthusiasts will agree that you should steer clear of the heads with casting number 14102193. The factory TBI heads are said to be among some of the worst flowing heads GM ever released. Valve springs, magnaflux, and a valve job will cost you a couple hundred dollars or more, and that money would be better spent on better heads. The best bang for the buck comes from swapping to GM Vortec heads, but they require a special intake from Chevrolet Performance (chevrolet.com) or Edelbrock (edelbrock.com). Watch out for used iron Vortec heads with 100,000 miles or more on them; many will have cracks caused by the long-term heat cycling.

As for your drivetrain, your SM465 and NP205 combo will work fine for most general off-road scenarios. It’s an extremely durable combo that should handle pretty much whatever you can throw at it. The somewhat undesirable 1.96:1 ratio low range of the NP205 will be offset by the 6.55:1 ratio First gear in the SM465. When combined with the 4.10:1 ratio axle gears you’ll have an admirable 53:1 crawl ratio, which should be plenty slow for technical trail work. Speaking of 4.10:1 ratio axle gears, they should be fine with 35-inch tires on-road. If you make the bump up to 38-inch tires, you would likely be better off with 4.88:1 ratio axle gears.

As you likely know, the Dana 44 front axle assembly will be your weak point in this combo. You’ll want to keep an eye on the axleshaft U-joints if you decide to run a locker of some sort up front, especially with 38-inch tires. For general 4x4 use with an open front differential you shouldn’t have any problems.

You could conceivably slap this powertrain in any number of 4x4 vehicles, although you’ll probably want something with a wheelbase of at least 105 inches or so. A 110-inch wheelbase might be better. This will provide the necessary space for a proper rear driveshaft with the lift required to fit up to 38-inch tires. Look for a fullsize Chevy Blazer, GMC Jimmy, ’78 or later Ford Bronco, or pretty much any standard-cab shortbed 1/2-ton pickup truck. The amount of suspension fabrication required will depend on the vehicle you select and what vehicle your Dana 44 front axle originally came from.

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