In the 1990s, British automotive journalist Mark Walton drove a Dodge Viper pulling a travel trailer to 126.7 mph to establish a modern World Record speed. In 2002, a highly modified escort rally car bumped the record to 128.8 mph. In 2003, the record took a big jump. The combination of a 2-mile-long South African runway, a 700hp twin-turbo Mercedes, and an aerodynamic caravan boosted the record to 139.11 mph.
The record has stood at 139.11 mph since then, but not for a lack of trying. The British-based TV show Top Gear tried to break the record (then at 128.8 mph) with a modified Mitsubishi EVO, only to run 125 mph before blowing up the engine. More recently, an unnamed European company attempted to break the 139-mph record with a Porsche Cayenne S Turbo, only to have its aerodynamic trailer come off the ground at speed! In the last few decades, the record had moved around from Australia to Britain to South Africa, so it’s clearly an international record -- and not an easy one to break!
We needed a plan if we were going to tow faster than anyone else on the planet -- and some crazy friends to help us along the way. We found those partners in Pacific Performance Engineering (PPE) and Carson Trailer, which builds a wide range of campers, car trailers, and toy haulers. For our haul truck, PPE would be bringing their famous diesel drag truck dubbed “The Sleepermax” out of retirement. The truck already had 744 rear wheel horsepower (rwhp), but for record-breaking speeds, additional horsepower had to be on the table. To that end, the truck’s large twin turbos were swapped out for an even larger pair. A set of Exergy Engineering injectors provided 100-percent more fuel capability than stock, while a Nitrous Express (NX) dual-stage nitrous system was on hand in case we needed the extra horsepower.
For the trailer, we were understandably worried about aerodynamic stability, sway, and the trailer otherwise getting loose on us. To complicate matters further, we couldn’t use any type of sway control for the record attempt. In an effort to remain aerodynamically neutral (no lift or downforce), we chose Carson Trailer’s Kalispell. It was light, used a single axle (less rolling resistance), and was of 140-mph build quality. The Carson trailer was a perfect embodiment of a record-setting trailer in that it was compact (only 7½ feet wide and 10½ feet long), but it retained full amenities, including a bed, full-size refrigerator, and kitchen appliances -- all for about $10,000.
Our greatest fear during this attempt was crashing at 100-plus mph, so we spent a whole lot of time researching where the rubber meets the road. After speaking with many different manufacturers -- some of which simply said, “No way!” -- we finally settled on a set of 305/50R20 Toyo Proxes ST IIs mounted on 20x10 BMF wheels for the truck. The Toyos are rated at 149 mph, so we knew we’d be safe.
The trailer tires also had to be specially ordered. Traditional trailer tires are built for strength rather than speed and are actually only rated for 65 mph. For the trailer, we selected tires originally meant for a heavyweight sports sedan -- a set of Goodyear Gatorbacks. They were rated for the speed we wanted to go, and each could support 1,477 pounds of weight.
Doing the Math
With the truck and trailer prepped, we had to make sure we could actually break the existing record, and that’s where a fair amount of math came in. While we could have lowered the truck, put on racing tires, and made numerous aerodynamic modifications to make it look like a pure race vehicle, we decided to see if we could break the existing record driving just as one would normally drive down the road. After all, as former Diesel Power Editor David Kennedy said: “Race vehicles look like a race car driver could drive them…a normal vehicle looks like anyone could drive it.”
So if we were going to eschew the aerodynamic modifications, we needed a way to figure out how much power we’d need to move our brick towing a brick through the air. For this, an online calculator (www.rbracing-rsr.com/aerohpcalc.html) proved very helpful. The calculations said we’d need more than 1,000 rwhp to go 140 mph, based on a drag coefficient of .60 (which is bad) and a frontal area of 75 square feet (which is even worse). As it turned out, RBR’s calculator was almost dead-on.
One modification we were allowed to perform was replacing the normal 65-mph-rated trailer
Since most trucks don’t go 140 mph in four-wheel drive, we figured the front differential
To keep the exhaust clear of the trailer and maintain its diameter without any expensive b
Testing for the Record
Testing for the record was one of the hardest parts of the whole ordeal. The dragstrips wanted no part of us, and even a retired airstrip didn’t want us on their runway. “You need 3,000 hp to do it, plus, you’ll crash through our fence and die,” was their general opinion.
What we knew we could do, though, was to test the truck and trailer independently, so that’s what we did. To test the truck, we ran some 12-second passes at Fontana Speedway and also made some dyno pulls. After a few pulls and some tuning changes, we yielded a wild, 1,004 rwhp -- without nitrous!
As for the trailer, we mostly tested it behind our ’95 Dodge Ram, known as Project Triple Threat. We found we could hit 100 mph pretty easy, and the trailer remained stable -- even after emergency freeway lane changes. In talking with Carson Trailer’s David Endres, we were told in this situation the optimal hitch location was a few degrees below level, and our trailer tongue weight should be about 15 percent of the 2,700-pound total.
Finding a Venue
After months of building, testing, and math, we still had to find a place for the attempt. The existing 139.11-mph record had been set on a 2-mile-long South African runway. Since the Diesel Power magazine effort had a lot more horsepower, but also a lot more aerodynamic drag, we felt it would take about 1-1/2 miles to reach our top speed, with another 1/2 mile to stop. We set our sights on an arrow-straight road of 2 miles or more, which is actually pretty hard to find here in the Los Angeles area. Initially, we planned on running out at El Toro airfield, but they said they lacked the room. The El Mirage dry lakebed got dismissed because of drag and traction, and a 3-mile-long road up in Lancaster, California, was out because of the cost of shutting down a public road. So we arrived at the Mojave Air and Space port, a 2-mile runway located in the desert north of Los Angeles.
As it turns out, our luck was doubly good, as MKM Racing Promotions was holding its annual Mojave Mile, a standing 1-mile event that measures a vehicle’s exit speed. The event coordinator, Mike Borders, was surprisingly receptive to our crazy idea and agreed we could at the very least make a few 120-mph test passes there. Then tragedy struck. At a private event before the Mojave Mile, an older gentleman had a heart attack and died at the wheel of his Ford GT, leaving the car to spin off track at more than 200 mph. The airport was understandably concerned and told Mike they would be enforcing the rules with an iron fist. “Well, there are a few journalists who want to try to go more than 120 mph while towing a trailer,” he admitted, and that was it. The day before our scheduled run, we were sunk.
After a few months of stagnation and careful consideration, we knew the next best answer had to be El Mirage dry lake bed. It wasn’t perfect, being that it was a dirt surface, but it had the space we required and was affordable. It was then everything came into focus, and we knew our attempt was to be made at El Mirage.
Before our official run, David from Carson Trailer and Corey Macha from PPE met up with us at El Mirage to do some testing. We unhooked everything and went 104 mph on a test pass. Then we hit 125 mph with the truck and trailer -- matching Top Gear’s attempt -- while keeping EGT less than 1,600 degrees, and without using nitrous. Our official run needed us to go 15 mph faster, and we knew those last 15 mph were going to be tough.
An adjustable hitch was used for the record run, so we could adjust the tongue height to g
The trailer’s brakes, axle, and suspension all had to remain unmodified, per the rules, if
We were somewhat worried about how the Carson Kalispell trailer would hold together at mor
“I just need a little more!” Associate Editor Jason Sands can be seen saying to PPE’s Cory
With a healthy dose of the go-fast button, we’d done it, and broken 140 mph. The second 0.
“Whoa, you guys have a propane tank on that thing? I hope it’s not full!” said the fire cr