What is Bio-Oil?
Short Answer: It's the "other" diesel

A lot has changed since the 5.9L Cummins B-series engine was first offered in '89 Dodge pickups. The injection systems, cylinder heads, emissions equipment, and turbos have all seen dramatic improvements over the last 20 years. However, the one thing that Cummins has never altered was the displacement. During the same time period, General Motors upsized its diesel from 6.2L to 6.5L, and then to the current 6.6L engine for the Duramax. Ford sold 6.9L, 7.3L, and 6.0L in the past, and currently sells 6.4L Power Stroke engines, continually improving in order to meet various performance, fuel economy, and emissions requirements.

If you decide to open your own business, you'll most likely need a company car. In many cases, you'll need more than one. This is where diesel vehicles come into play. If you need a fleet of vehicles for a company, diesels can save a business owner a significant amount of money. Buying a diesel-powered Jetta as a get-around company vehicle could save thousands of dollars a year in fuel costs compared to a similarly sized gas-powered vehicle.

Though not the first electrically controlled diesel in the light-duty market (the Ford 7.3L Power Stroke was), the General Motors 6.6L Duramax is recognized as one of the most sophisticated. It boasts four-valve aluminum cylinder heads, excellent component packaging, and a reputation for durability, power, fuel economy, low combustion noise, and very little vibration. Ironically, this high-tech engine exists due to the government-mandated emissions standards that required a 90-percent reduction in tailpipe discharge from previous mechanically fueled designs. Thus, gasoline-style engine management was required to tame and improve upon the diesel engine.

The '94-'98 Cummins 5.9L engine has been the mainstay of diesel power in Dodge trucks, and has a reputation as an excellent performer with the ability to make some serious horsepower. One of this engine's features that makes it so desirable is the Bosch P7100 inline mechanical injection pump. This injection pump, often called a "P-pump," is the Holley Four-barrel carburetor of the diesel world. The P7100 pump has been around forever, is practically bulletproof, and is very tunable for high performance.

If you've noticed that Project 12-Valve has been missing from the magazine for the last few months, you're not alone. We've received quite a few letters wondering what happened to it, and we're stopping by this month to give you an answer. As far as the magazine goes, Project 12-Valve is considered a completed vehicle, and we now have our sights set on making Project Rust Bucket into a truly awesome daily driver. We didn't need two cheap truck buildups in the magazine, and we went way over budget on Project 12-Valve anyhow. Our '89 Dodge is also much lighter, which translates into better dragstrip times and improved fuel economy.

There's one thing that the new 6.4L Power Stroke, 6.7L Cummins, and LMM Duramax engines all have in common-they are forced to breathe through a diesel particulate filter (DPF). This "trap" is actually designed to get clogged up with soot, and that's no joke. Since clouds of black smoke can quickly plug up your DPF, the engineers behind your favorite diesel programmers had to work overtime to create new tunes that could operate in harmony with the new emissions equipment while still providing huge power increases. Here, we've gathered together many of the programmers already on the market with tunes specifically designed for the new DPF-equipped trucks. They'll let you do things like check the status of the DPF in real time, or even command a DPF regeneration when it's convenient for you. If you don't see your favorite brand of programmer on the list, make sure to check the company's Web site and do a search on diesel message boards for the latest information. New programmers for these three diesel engines are being released all the time.

In the last year or so, third-gen Dodges ('03-'07) have really come on strong. We're starting to see more and more of them produce big power numbers, and also run speedily down the dragstrip. At the recent OBX Outlaw race that was cancelled due to rain, we ran into a couple unbelievably strong common rails. The owners were nice enough to share their combinations with us so that our readers can see what it takes to make some huge power numbers with a CP3-fueled Cummins.

Often in our line of work, we hear a lot of stories about what you "can" and "can't" do. When we heard of an '05 Ford that was running mid 13s in the quarter-mile on almost all stock parts (including the transmission), a red flag went up. Surely this must be one of those situations where there is more to the truck than meets the eye. Well, we're here to tell you that yes, it can be done, and it just takes a careful selection of parts and some good tuning.

The 6.6L Duramax diesel is an extremely versatile engine with lots of torque and plenty of durability-as the name would imply. For anyone looking for an excellent tow rig, race truck, or daily driver, this is one of the best to ever roll off an American assembly line. As is the case with most late-model offerings, improving the breed is a matter of careful engineering and creative thought. Yet when it comes time to modify your diesel engine, which modification should you do first?

The power output of a diesel engine is directly proportional to the quality and quantity of the air and fuel going into and out of the combustion chambers. So naturally, most aftermarket diesel performance parts are designed to add more air and fuel into the engine. Increasing the air moving through a diesel engine tends to result in a leaner air fuel mixture, so in order to build substantial power, extra diesel fuel has to be added.

Dodge heavy-duty trucks are known for a lot of things, but unfortunately, precision steering isn't one of them. If you own one of these trucks, you've likely experienced sluggish steering, road wander, or worse yet, the dreaded "death wobble." These problems are more prevalent in the '94-'02 trucks (but common to some degree in almost all solid front axle trucks), and can worsen when larger tires and/or weight are added to the truck.

When we bought our '89 Dodge, we found out during the long drive home that it had a top speed of about 75 mph. The horsepower was there, just not the rpms. When we put the truck on the dyno, our problem became even more obvious as we noticed our truck was pulling back fuel to the point where we only had about 50 horsepower at 80 mph. It was no wonder our truck felt so slow at highway speeds.

The clatter and rumble of a big diesel has always been part of the excitement of driving our oil burners. It subtly advertises that we just might have something that the gas rigs don't. Those of us with an ear for diesel power can close our eyes and say, "There goes a Cummins," or "That's a Power Stroke."

Recently, we took a trip down to Advanced Flow Engineering in Corona, California, to witness another chapter of the age-old Ford vs. Chevy battle. With the keys in our hands to an '06 6.0L Ford and an '07 LBZ Chevy, courtesy of Laguna Speed, we were ready to let the sparks fly. Both trucks would be dyno'd in stock form to get a baseline, then fitted with AFE intakes and exhaust kits, and tested again. Finally, an aftermarket programmer provided by Rolling Big Power would be added to both trucks for their final runs.

Stock is good, but there's always room for improvement. When GM Powertrain set out to build a Duramax-powered GMC truck to help promote its new Duramax boat engine, it turned to Diesel Power to develop a concept. Knowing that it would need a truck that could tow and be reliable, we hooked GM Powertrain up with the folks at Gale Banks Engineering for the installation of an exhaust system, intake, high-performance intercooler, and one of Banks' new LMM Six-Gun programmers with the PDA option.

When it comes to diesel trucks, more information is always better. With project Rust Bucket, we were confident in doing quick dyno pulls, but still felt the need for gauges while driving on the street or down the dragstrip. Our truck is an '89, which means it is a non-intercooled 5.9L Cummins model, so we were worried about high exhaust gas temperatures. Also, we've been told our stock turbo can only live at up to 35 pounds of boost before its compressor wheel will make an early exit. As cheap as we wanted this project to be, we figured a set of gauges would be better than a trashed turbo or damaged engine.

Diesel truck transmissions have a hard job. They have to stand up to the tremendous torque that a diesel engine can produce, tow heavy loads, and are even subject to the occasional drag race or sled pull. To find out more about diesel transmissions, we asked Dave Goerend of Goerend Transmission and Mike Lovrich of Inglewood Transmissions 20 questions about them. Goerend and Lovrich are the actual guys who get their hands dirty rebuilding these units in their shops. Although he owns a shop that can rebuild any type of transmission (he even makes his own converters), Goerend specializes in Dodges, while Lovrich rebuilds Chevy, Ford, and Dodge diesel transmissions. Both techs have built transmissions for 400hp trucks, as well as 1,000hp trucks, and everything in between. In addition to their opinions, we also threw in our own, from what we've seen at Diesel Power Challenge and other events.

One of the easiest ways to make big power is with nitrous oxide. While there are kits on the market today that provide hundreds of horsepower over stock, we've also noticed that many of the "big boys" are building their own custom nitrous systems. If the idea of 400, 500, or even 600 more horsepower at the push of a button tickles your fancy, read on. We're going to tell you all you need to know to make your own crazy nitrous system.

In the diesel performance world, Ford 6.0L Power Stroke engines have a bad reputation for blowing head gaskets and sticking EGR valves when owners modify them. There are a number of reasons why people have problems with their modified 6.0Ls, but one of the main culprits is the exhaust gas recirculation (EGR) system.

One of the biggest "bang for the buck" products for your diesel is nitrous oxide. There's not much else on the market that can boast an increase of 100 or more horsepower, for less than $500. With our project Rust Bucket Cummins-powered Dodge Ram, looking for dirt-cheap horsepower meant that nitrous was the next logical step after our fuel modifications. A nitrous system would give us the air we needed to burn up excess fuel without an expensive turbo upgrade, and since nitrous oxide is 36 percent oxygen (versus about 21 percent for regular air), we figured a nitrous-assisted vehicle might make more efficient use of the fuel that was available.

When we last left our Project 12-Valve Dodge, it was making a little over 300 horsepower at the rear wheels, but exhaust gas temperatures hadn't dropped as much as we had hoped. We were looking for EGTs in the 1,350 range, and instead were at 1,450-1,500. We'd talked to a few people who told us that the stock intercooler was a restriction, so we decided to test that theory by installing a new "Cool-It" intercooler from BD Diesel Performance. It was our hope that we could get some more power through cooler, denser air and also keep our EGTs from getting out of control. In order to duplicate real-world driving conditions, we also did a tow-test simulation, where the load dyno at Imler Diesel was used to simulate the stress of an 8,000-pound trailer up a 6-percent grade. This way, we could not only measure peak power, but see how our new intercooler stacked up under a severe load.

Our Project 12 valve has seen a lot of miles, and its mismatched tires had reached the end of their lifespan. We were especially worried about the front tires, which had seen about 20,000 miles on a bad alignment. It was time for new ones, and we were on the lookout for tire that would be good for the truck's all-purpose needs.

When it comes to interior space in a pickup truck the Dodge Mega Cab leads the pack. With 44.2 inches of rear passenger leg room and 16.6 square feet of flat storage area for transporting large items, there just isn't a better pickup in terms of interior volume. However, ordering a new Mega Cab comes with one snag. Dodge doesn't offer it with an 8-foot bed, and according to our sources, it doesn't plan to anytime soon.

What happens when magazine guys get bored on weekends? More power, that's what. We were waiting around for gauges and some other stuff for our '89 Dodge Ram while we tried to think of a cheap way to solve our slipping transmission problem. Then we realized, "Hey, we haven't turned up the rotary pump in this thing yet!" and set to work with simple hand tools to discover how much power we could get out of free injection pump mods. First, we took off the pump top and rotated the diaphragm. This produced a power gain that was just barely noticeable on our test drive. We'd heard the big power boost was in the full fuel screw, so that was next. The screw had a collar on it from the factory to keep us from adjusting it more than about of a turn, so we cranked it all the way in. It definitely felt faster, but there was still no smoke so we knew we could go further.