Upgrading to a High Performance Drop-In Turbo on 5.9L Cummins

Upgrading to a Drop-In Turbo on the 5.9L Cummins Diesel

The 5.9L Cummins turbo diesel engine is widely regarded as one of the most reliable and powerful options on the market. Found in Dodge Ram heavy-duty trucks from 1989 to 2007, these inline-six engines are revered for their capability to produce abundant low-end torque. However, even the most stalwart stock parts eventually require upgrading, especially when owners add performance modifications or subject their trucks to demanding towing and hauling duties.

Benefits of a Drop-In Turbocharger Upgrade

One popular upgrade for the 5.9L Cummins is swapping the factory variable geometry turbo (VGT) for an aftermarket drop-in unit. Drop-in turbos deliver higher boost pressure while maintaining drivability, allowing the engine to generate increased horsepower and torque output.

Drop-in turbocharger benefits include:

• Higher horsepower and torque numbers
• Increased throttle response
• Better engine efficiency
• Cooler exhaust gas temperatures (EGTs)
• Minimally invasive installation

Drop-In Turbos vs. Factory VGT Turbos

Factory VGT turbos utilize adjustable vanes inside the turbine housing to optimize boost across the RPM range. However, their complexity makes them prone to sticking and slow spool times. An aftermarket drop-in turbo uses a fixed vane design optimized for performance instead of emissions compliance and drivability.

While a little lag is inherent with fixed vane turbos, most 5.9L Cummins owners find the tradeoff worthwhile for the massive power gains. With the right supporting modifications, drop-in units can support over 800 horsepower!

Important Drop-In Turbo Specs

Those shopping for a 5.9L Cummins turbo upgrade will want to consider factors like:

• Compressor wheel size - Larger wheels flow more air, generating higher boost levels
• Turbine housing A/R - The area-to-radius ratio influences exhaust flow and spool rates
• Bearing system - Ball bearing turbos handle higher RPMs than journal designs
• Turbine wheels - Lightweight forged aluminum or MMC wheels spool faster than iron options

Matching the turbo to your performance goals and engine setup is crucial for optimal drivability and durability.

Popular Drop-In Turbocharger Brands

Venerable manufacturers like BorgWarner, Garrett, and Holset account for many of the most popular drop-in turbo options. However, niche brands catering specifically to the 12-valve and 24-valve 5.9L Cummins also offer great packages.

BorgWarner

Known for both OE and aftermarket turbos, BorgWarner supplies durable, value-oriented upgrades ideal for daily drivers. The S400SX-E and S480 feature large, efficient compressors to deliver elevated boost levels with minimal lag.

Garrett

Turbocharging pioneer Garrett offers an extensive range spanning small tuner upgrades to high-horsepower monsters. The popular GT45R and GT55 deliver street-friendly spool with 500+ horsepower potential when coupled with supporting mods.

Holset

Holset earned its reputation supplying ultra-reliable turbos for OE applications. Their HY35 and HX55 downsized models maintain that same OEM-quality construction for the aftermarket, striking an ideal balance of durability, spool, and top-end power.

Hamilton Cams & Turbo

This niche manufacturer crafts purpose-built turbocharger, camshaft, and injection pump upgrades tailored specifically for the 5.9L Cummins platform. Their specialized Nightmare, Cyclone, Hurricane, and Storm turbo models are favorites among truck pullers and drag racers.

Supporting Modifications

While the turbocharger might be the heart of any 5.9L Cummins performance build, owners shouldn't overlook supporting modifications that allow their engine to fully capitalize on the upgraded boost levels:

Fuel Supply Upgrades

Instead of leaning out the fuel mixture to cool EGTs during heavy load conditions, upgraded fuel system components allow an engine to safely burn more fuel for superior performance:

• High flow fuel injection pumps supply increased quantities of diesel
• High pressure oil pumps maintain stable injection control pressures
• Fuel injectors flow higher volumes into the combustion chamber

Engine Management Tuning

Aftermarket electronic control modules and custom tuning software calibrate fueling, boost, transmission, and other parameters for optimal drivability instead of compliance.

Interior Hardware

Properly upgraded engine internals allow an engine to withstand much higher cylinder pressures and abuse. This includes:

• Forged connecting rods for extreme loads
• Thicker head gaskets prevent blowing out between cylinders
• High strength head studshelp clamp the head securely against high pressures

Without shoring up these weak points, no stock 5.9L Cummins will live long under the strain of an aggressive drop-in turbo upgrade!

Installing Your New 5.9L Cummins Turbocharger

Replacing the turbo on a 5.9L Cummins isn't drastically complex, but does require some mechanical competency. Or, owners can pay an experienced diesel shop a few hundred dollars to swap on their new turbo professionally.

With the stock VGT removed, most drop-in units reuse the factory exhaust and oil lines. Tuning will then center the vanes properly within the new fixed vane turbine. After double checking all clamps, sensors, and connections, owners can safely enjoy their truck's newfound power!

FAQs

What are the main benefits of upgrading to a drop-in turbo?

The main benefits are increased horsepower and torque output, improved throttle response, better engine efficiency, lower EGTs, and relatively simple installation since it reuses most factory mounting points.

What size compressor wheel should I choose?

Larger compressor wheel diameters flow more intake air, generating higher boost levels. However, too large of a wheel could overboost the stock engine internals and cause failure over time. Work with an experienced diesel builder to select a properly sized wheel for your power goals.

Do I need a built engine to safely run a big turbo?

Yes, upgraded internal engine components like forged connecting rods, thick head gaskets, and stronger head studs are highly recommended when running aggressive turbocharger upgrades. The stock soft parts won't hold up to the extreme pressures of high boost for long.

What supporting mods help a drop-in turbo perform optimally?

Upgraded fuel supply components, electronic tuning, and built internals allow the engine to capitalize on the extra airflow instead of just creating excess heat. Supporting modifications are always recommended when increasing boost via a larger turbocharger.