Garrett GT3782VA vs GT3794VA: Which Turbo Is Right for You?

Garrett GT3782VA Turbo Rebuild Service →  |  Garrett GT3794VA Turbo Rebuild Service →

Quick Overview

The Garrett GT3782VA and GT3794VA are both GT37-frame variable geometry turbos, but they belong to different engines and do different jobs. The GT3782VA is the factory turbo on the Ford 6.0L Power Stroke: 2003-2007 Super Duty, 2003-2005 Excursion and 2004-2010 E-Series. The GT3794VA is not a factory turbo at all. It is Garrett’s PowerMax Stage 1 upgrade (773540-5001S) for the 2004.5-2010 6.6L Duramax LLY, LBZ and LMM, where it replaces the stock GT3788VA.

In Garrett’s naming the last two digits are the compressor wheel size in millimeters: 82 mm on the GT3782VA, 94 mm on the GT3794VA. The two are not interchangeable. Housings, oil and coolant connections and vane control all differ by engine, so the truck decides which one you need.

Which Spools Faster?

On paper the GT3782VA, with its smaller 82 mm compressor wheel, is the quicker-responding unit, and the 94 mm GT3794VA gives up a little low-speed response for airflow. In practice the question does not arise, because each fits a different engine.

The comparison that matters to a Duramax owner is the GT3794VA against the stock GT3788VA. Garrett markets the PowerMax as a drop-in that keeps variable-vane response while adding airflow at the top of the range.

Which Supports More Power?

The GT3782VA supports a stock or lightly tuned 6.0L Power Stroke. The GT3794VA is sold for Duramax trucks that make more than stock power: retailers rate the Stage 1 at roughly 500 rear-wheel horsepower with supporting fuel and tuning.

An upgrade turbo is not a stock replacement part: Garrett states that its performance kits are not legal for use on public roads, so check the emissions rules that apply to your truck before fitting one. At least one national retailer lists the GT3794VA as not for sale or use in California.

Which Is Right for Your Application?

• Ford 6.0L Power Stroke: the GT3782VA. See the 6.0L Power Stroke turbo rebuild page.
• 2004.5-2010 Duramax (LLY, LBZ, LMM), staying stock: the GT3788VA.
• 2004.5-2010 Duramax, wanting more airflow: the GT3794VA.
• 2011-2016 Duramax LML: its own version of the GT3788VA. See the LML turbo rebuild page.
• Ford 6.7L Power Stroke: neither. That engine uses other Garrett turbos.

Rebuild Considerations

Both rebuild the same way in outline: full teardown, vane mechanism cleaned and freed, new bearings and seals, and a balanced rotating assembly. The vane control differs. The 6.0L unit moves its vanes with engine oil through a VGT control solenoid and has no position sensor; the Duramax units add a vane position sensor that the engine computer watches. Parts are specific to each assembly number, so order by the number on the tag.

Quick Comparison

How to Tell Them Apart

The reliable way to tell a Garrett GT3782VA from a GT3794VA is the identification tag, not appearance alone. Both are GT37-frame turbos and their housings can look similar at a glance, so confirm the model designation and assembly number stamped or plated on the unit before ordering rebuild parts. Exact configuration (wheel trim, housing A/R, calibration) varies by specific part and assembly number even within the same model name, so the assembly number is what actually determines which parts are correct for your unit.

For the full process, see our How to Identify a Garrett Turbo guide.

Frequently Asked Questions

PT Turbo Warranty

• 12-month, unlimited mileage warranty against defects in parts and workmanship
• Final quality inspection on every rebuild: leak test, visual inspection, actuator or wastegate function check
• In-house CIMAT VSR balancing with a balance report included
• Nationwide mail-in service — you don’t need to be local

Pricing

Most rebuilds require inspection before final pricing. Standard rebuild pricing depends on the turbo model, parts availability, wheel condition, shaft condition, housing damage, and whether upgrades are requested. PT Turbo inspects every turbo and sends a quote before any work begins — no surprise charges.

See our turbo rebuild price list for the standard price of each turbo we rebuild.