A Wrangler TJ Crawlin’ on 40’s with a 2.5-Liter

To be completely honest, I’ve never driven a four-wheel-drive with anything less than six-cylinders. So, when I was chosen to drive Cameron Harris’ Jeep Wrangler TJ, I figured it had to have at least an inline-six. Then I fired it up and realized there were two cylinders missing.

During the Yokohama Geolandar X-MT debut, test vehicles were provided to us by GenRight and their employees or brand ambassadors. Mine was a Jeep TJ Wrangler owned by Cameron Harris from Utah. Yes, he and his father drove their rigs from there all the way to Landers, California – the home of Johnson Valley OHV Park and the King of the Hammers.

It’s Not the Size of the Dog

It’s equipped with a 2.5-liter I4 and an AX5 five-speed manual backed by an Atlas with a 5.00:1 transfer case. It also has 5.38:1 gears in the Currie Enterprises axles. Attached to the Wrangler chassis and those axles are a set of King Off-Road Racing Shocks with Remote Reservoirs. The only modification done to the engine are a pair of Venomaire 2XS forced air intake tubes. I had never heard of this and, when it was initially described to me, it seemed like the same “snake oil” as “Tornado Air” and those “electric superchargers” you find on sale on Aliexpress, eBay, or the like.

Wait, What?

Yeah, I’m still not entirely sold on what they are doing to the engine. The gist is that the 2XS is an electric axial compressor fitted in the intake tube. It forces more air into the throttle body when the engine needs it at high-altitude or high-RPM. Getting air mass into the engine during those times is what chokes the engine (which is why high-RPM engines like short runners and big intake ports). However, the company claims, adamantly, it is not a turbo or supercharger but just a way to get more air into the engine. Cameron stated it has made an impact as the Wrangler suffered from stalling at high altitudes and hasn’t since owning the system.

As I drove it, it certainly didn’t struggle for power like I expected it to during the climb. It wasn’t a V8 or six-cylinder killer by any means, though. One issue I did see was that it caused some over-fueling by the ECU when the throttle was off. While it wasn’t running with any catalytic converters, you could smell a strong scent of raw fuel. You do expect that with gutting the cats, but there was more than what you’d normally get. Just wish I knew exactly what was going on. It can’t be putting out more than 3- to 5-PSI at most as they claim you don’t need to tune for it. This makes me further suspect of the product but the Wangler ran fine besides the after-firing.


Hiking Boots

The Yokohama Geolandar X-MTs installed for this test drive were a set of 40×13.50x17s mounted on Walker Evans Racing Beadlock Wheels. These are a much larger set of tires than what Cameron normally runs – a 38×12.50×17. You could feel it but, again, the little 2.5-liter Wrangler would just drive along without giving too much of a fit. Well, so long as you flogged it ran at high-RPMs. With the Geolandars aired down, the little TJ with the X-MTs made crawling feel like a breeze.

Strong Legs

The axles under the Wrangler, as I mentioned earlier, are a set of Currie Enterprises Rock Jock axles. The fronts feature Warn Locking Hubs with a locker in the differential. The rear used an ARB Air Locker and this combination works best for most street driven rigs. Especially so when you can’t afford an air locker front and rear.

Keeping one or both front hubs unlocked allows the wheels to turn at different speeds when you go around corners until you get off-road or just need the fronts locked. Then, when you need it, just lock the unlocked hubs. The air locker allows the rear to be fully locked on demand from inside the TJ. In most of the run up to Chocolate Thunder, the front hubs were kept unlocked until I hit steep areas with big rocks.


While it would have to be shifted down a gear in some places, it was fine for up to third gear in high-range and fourth and up for low-range. Other than that, this little four-banger Wrangler stayed right with the six- and eight-cylinder Jeeps of the rest of the GenRight crew. It was interesting that a lot the tricks I learned in drifting and road racing helped me out as much as it did. If I was starting to lose power, I would clutch kick to keep it in the power band. If I needed to shift down, heel-toe shifting in low-range smooth. It certainly makes me think about doing a five-speed swap on my Pathfinder when I eventually make it 4WD.

However, that lack of power was missed when I hit sand. Our first pass up a tall sand hill was done in high-range to second gear on the hard-packed stuff. Once the rest trucks went up and down the hill, the X-MTs dug like sand paddles. Great for V8 trucks, not so much for a 2.5-liter. Once it dug in, it bogged down on us unless I clutch kicked. Fortunately, when I began to lose too much power or stalled out, all I had to do was turn back down the hill and allow gravity to assist me out of the rut.

How it was Meant to be Driven

After the sand hill, I allowed Cameron to take over driving the Wrangler, so I could get photos of it driven in true anger. It was also a delight to watch some of the Yokohama’s Japanese crew get taken up the rocks for the first time in their lives. Some of their faces were pure amazement, some were a bit of terror. Even Fardad Niknam, Yokohama Senior Director of Consumer Product Planning and Marketing, took a ride in Cameron’s father’s tube-chassis, four-wheel steering rig and was quite surprised by his own tire’s capabilities.

Driving Cameron’s four-banger TJ showed me how much fun driving an underpowered rig and keeping up with the inline-six and V8 powered rigs really was. It was built right by working directly with Tony Pellegrino before Cameron moved to Utah. It’s certainly made me take some new considerations into future off-road projects.


Justin Banner

Justin Banner, Lead Editor and Founder of Carbage Online, has been involved with the automotive media and industry in many capacities and now tackles publication ownership with CarbageOnline.com. Prior to that, he has freelanced for top online publications of modern media that include Speedhunters, MotoIQ, Super Street Online, Hot Rod Magazine and many others. All due to his nearly 20 years experience as a mechanic, service writer, and technical support in the automotive industry. Justin is also a Journalist Level member of the Motor Press Guild - an industry recognized entity of professional automotive journalists - since 2015.

4 thoughts on “A Wrangler TJ Crawlin’ on 40’s with a 2.5-Liter

  1. I read your review about the VenomAir Smart Intake. There is some miss information in your article and it is less than flattering. Keep in mind, that tired old 2.5 liter, 120 HP engine is trying to turn 40 inch tires. No, it will not over fuel your vehicle and they do not run at idle. I have Dynos from the top tuners in Utah that prove out about 20 to 30% torque and horse power, 20 increase in mpgs, with a 20% reduction in emissions. With over 400+ units in service, I have plenty of feed back, testimonials and case studies to back up my claims.Perhaps we should get together and do appropriate review? Feel free to contact me any time to discuss?

    1. Hey, Dan, I wasn’t really meaning to put your company down, which is why I stated I wish I knew more about what’s going on. To explain, I’ve been running the numbers on this and something isn’t adding up right. At 120-horsepower, you would be looking to add about 24-horsepower at a 30-percent increase. To get that 156-horsepower, you’d need about 1.42-PSI of boost pressure. The rough math I used to get that boost requirement is 156-horsepower=.0645*150ci(X+14.7psi). To get one-PSI of boost pressure, you need about 1.3-kilowatts of energy which requires about 68- to 70-amps at 14-volts and about 78- to 80-amps at 12-volts. However, the site says you draw between 10-amps at idle and 50-amps at full power. Could you explain what I am missing?

      1. Justin;

        Thank you for your reply. I love talking about my Venomaire Smart Intakes. First let me say, we are not a compressor, like a turbo supercharger. We don’t create boost. That is not our thing. We create Thrust. That is what propels a jet, 600+ mph. So we can’t compare your boost numbers to our systems. Our goal is not to compete with Turbos and the like. Our goal is to have a system that gives the average driver a decent increase in horsepower, without all the headaches of the aforementioned turbos at an affordable price as well as improve fuel economy and reduce emissions. If you looked at Cameron’s set up, you will also notice how simple the install is. Anyways, that’s all I have time for, this morning. Please ask any questions. You’ll probably have a hard time shutting me up.

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