If you've been hunting for a new turbo para ram 3500 diesel, you've likely realized that while the factory Holset is a workhorse, it definitely has its limits once you start asking for more out of your Cummins engine. Whether you're dealing with a blown stock unit or you're just tired of watching your exhaust gas temperatures (EGTs) climb every time you hit a steep grade with a trailer, upgrading the turbo is one of those "make or break" decisions for your truck's performance.
Let's be honest, the Ram 3500 is a beast, but the factory turbo setup—especially the Variable Geometry Turbo (VGT) found on the 6.7L models—can be a bit of a headache. They're prone to soot buildup, the actuators fail, and they eventually start sticking. When that happens, you're stuck choosing between a standard replacement or stepping up to something that actually lets the engine breathe.
Why the factory turbo often falls short
The stock turbo para ram 3500 diesel is designed by engineers who have to balance emissions, noise, and "average" driving habits. It's built to provide quick spooling at low RPMs, which is great for stop-and-go driving, but it's quite restrictive. Because the exhaust housing is small, it creates a lot of backpressure.
High backpressure means your engine has to work harder just to push the exhaust out. This heat builds up in the cylinders, which isn't exactly great for the longevity of your head gasket or your valves. If you've ever noticed your truck feeling "choked out" at higher speeds or while pulling a heavy load, that's the stock turbo reaching its flow limit. Moving to an aftermarket setup can solve this by allowing more air into the engine and, more importantly, letting that hot air out much faster.
Choosing the right size for your driving style
When you start looking for a turbo para ram 3500 diesel, it's easy to get caught up in the "bigger is better" mindset. We've all seen those trucks at the track making huge boost numbers, but unless you're building a dedicated drag truck, you probably don't want a massive S400 frame turbo as your only charger.
The daily driver and towing setup
If you use your Ram 3500 for what it was built for—hauling heavy stuff—you need a turbo that spools fast. A 63mm or 64mm "drop-in" replacement is often the sweet spot for the 6.7L Cummins. These sizes provide a significant bump in airflow over stock without making the truck feel lazy at the stoplight. You'll notice that your EGTs stay lower while towing, and the truck won't feel like it's struggling when you're trying to merge onto the highway with a 15,000-pound trailer behind you.
The street performance build
For those who want a bit more "get up and go" and aren't towing at the max GVWR every single day, stepping up to a 66mm or even a 69mm turbo can be a lot of fun. These will definitely give you that pinned-to-the-seat feeling once the boost hits. Just keep in mind that with a larger fixed-geometry turbo, you might lose that exhaust brake functionality if you don't buy a specific kit to retain it. For many Ram 3500 owners, losing the exhaust brake is a dealbreaker, so that's something to keep at the front of your mind.
To VGT or not to VGT?
This is the big question in the Cummins world. The stock turbo para ram 3500 diesel is a Variable Geometry Turbo. It has a sliding nozzle inside that changes size to act like a small turbo at low speeds and a large turbo at high speeds. It also provides that famous exhaust braking power.
However, VGTs are complex. They have more moving parts, and as I mentioned earlier, they hate soot. If you do a lot of idling or short trips, that soot builds up and jams the mechanism.
Switching to a "fixed" geometry turbo (like a BorgWarner S300 or S400) usually means better reliability and much higher flow. The downside? You lose the integrated exhaust brake unless you install an inline aftermarket one. If you're a purist who wants a simple, bulletproof setup, a fixed-geometry swap is the way to go. If you love your exhaust brake and want snappy low-end response, looking for an upgraded VGT is likely your best bet.
Supporting mods you can't ignore
You can't just bolt on a high-performance turbo para ram 3500 diesel and expect it to work miracles if the rest of your truck is stock. It's all about the ecosystem under the hood.
- Tuning: This is the most important one. If you change the turbo, especially if you move away from a VGT, your truck's computer is going to be very confused. You'll need a custom tune (like EFI Live or EZ LYNK) to tell the engine how to handle the new airflow and to prevent it from throwing a dozen "check engine" lights.
- Fueling: Air is only half the battle. If you put a huge turbo on but don't have the fuel to spool it, you're just going to have a smoky, sluggish truck. Depending on the turbo size, you might need larger injectors or a modified CP3 pump to keep up.
- Transmission: This is the "hidden cost" of power. The 68RFE or even the Aisin transmission in the Ram 3500 can only handle so much extra torque. If you're adding a turbo that puts you over the 500-600 horsepower mark, start saving for a transmission build, because the stock clutches aren't going to be happy for long.
Common mistakes during the swap
One thing I see people do all the time when installing a new turbo para ram 3500 diesel is rushing the oiling process. When you put a brand-new turbo on, you absolutely cannot start the truck "dry." You need to prime that turbo with oil before you ever fire the engine up. If you don't, those bearings can be damaged within the first few seconds of operation.
Also, don't forget to check your intercooler boots. A new, high-performance turbo is going to push way more boost than your tired old stocker. If your boots are oily or cracked, they're going to pop off the second you hit 35 PSI. It's a cheap insurance policy to just replace them with heavy-duty silicone boots while you have everything apart anyway.
Keeping your new turbo alive
Once you've spent the money on a quality turbo para ram 3500 diesel, you want it to last another 200,000 miles. The best thing you can do is let the truck cool down before you shut it off. If you've just pulled a heavy grade or been driving hard, the turbo is incredibly hot. If you kill the engine immediately, the oil stops flowing and literally "cooks" inside the turbo bearings. This is called oil coking, and it's the number one killer of turbochargers. Letting the truck idle for two or three minutes—or waiting until your EGTs drop below 400 degrees—will save you a lot of money in the long run.
Ultimately, picking out a turbo para ram 3500 diesel comes down to being honest about how you use your truck. Don't build a race truck if you're actually a hotshot driver, and don't stick with a restrictive stock unit if you're looking for real power. Find that middle ground that makes the truck enjoyable to drive every day without sacrificing the reliability that made you buy a Cummins in the first place.