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Compound Kits

Complete Compound Turbo Kits for Cummins

Turn-Key Twin Turbo Systems - Both Turbos Included

Complete compound turbo kits provide EVERYTHING: small turbo, large turbo, manifold, all piping, mounting hardware—the complete twin-turbo solution.

These turn-key packages are perfect for owners starting from stock or wanting to replace their entire turbo system with perfectly matched compound components. Get 200-300°F cooler EGTs, instant response, 600-800+ HP capability, and the ultimate towing performance in one comprehensive package.

Both Turbos Included

Small AND large turbos - complete system

Perfectly Matched

Turbos sized to work together optimally

Everything Included

Manifold, piping, mounting, hardware - no guesswork

Ultimate Performance

200-300°F cooler EGTs, 600-800+ HP, zero lag

What's Included: Small primary turbo, large secondary turbo, manifold, ALL piping, ALL mounting hardware, oil lines, complete installation package.

Building in stages? Explore related categories: Add-A-Turbo Kits, S300 Single Turbos, S400 Single Turbos, 6.7 Cummins Exhaust Manifolds.

Best For: Stock turbo setups, complete overhauls, owners wanting perfectly matched compound system without piecing together parts.

Frequently Asked Questions for Compound Turbo Kits

A compound turbo kit uses two turbochargers working together, typically a smaller high-pressure turbo and a larger low-pressure turbo. The smaller turbo provides quick spool and low-RPM response, while the larger turbo supports high airflow and boost at higher RPMs. This setup delivers faster spool, higher horsepower potential, and lower exhaust drive pressure compared to a single turbo system.

Kits are available in configurations based on your power goals:

S300/S400 Complete Kit (Example: S366 small + S475 large):

  • Power range: 600-750 HP
  • Best for: Heavy towing (18-25k lbs), hot-shot, serious performance
  • EGT improvement: 200-300°F cooler
  • Ideal user: Hot-shot driver, heavy RV, performance enthusiast
  • MOST POPULAR configuration

S300/S300 Complete Kit (Example: S362 small + S369 large):

  • Power range: 500-650 HP
  • Best for: Daily drivers, moderate towing (12-18k lbs)
  • EGT improvement: 175-250°F cooler
  • Ideal user: Weekend tower, daily driver wanting compounds without going extreme

S400/S400 Complete Kit (Example: S475 small + S483 large):

  • Power range: 750-900+ HP
  • Best for: Competition, extreme builds
  • EGT improvement: 225-300°F cooler at high power
  • Ideal user: Sled puller, drag racer, extreme applications
  • Note: Requires extensive supporting mods

Quick guide:

  • Daily driver, 12-18k lbs, 500-600 HP → S300/S300
  • Heavy towing, hot-shot, 600-700 HP → S300/S400
  • Competition, extreme, 700-900 HP → S400/S400

Power depends on turbo sizes and supporting mods:

S300/S300 with moderate mods: 500-650 HP, great daily/tow balance

S300/S400 with full mods: 600-750 HP, best for heavy towing and performance

S400/S400 with extreme mods: 750-900+ HP, competition-level

Real examples:

  • 2005 5.9L, S366/S475: 685 HP, 1,425 lb-ft
  • 2015 6.7L, S369/S480: 745 HP, 1,550 lb-ft
  • 2006 5.9L, S475/S483: 875 HP, 1,825 lb-ft

Beyond numbers: Compounds make power smoothly, usably, and with 200-300°F cooler EGTs that protect your engine.

Compound turbo setups are designed for serious diesel performance. Benefits include quicker spool-up, improved throttle response, higher boost capability, reduced exhaust gas temperatures, and better overall efficiency under load. They are ideal for towing, racing, and high-horsepower diesel builds where a single turbo becomes a restriction.

Yes, when properly sized and tuned, compound turbo kits can work very well for towing and street-driven diesel trucks. The small turbo improves low-RPM response and drivability, while the larger turbo handles airflow under load. Many compound systems are specifically designed to balance daily driving manners with heavy towing and performance use.

Complete kits include BOTH turbos. Add-a-turbo includes only the large turbo.

Complete Compound Kit:

  • Includes: Small turbo + Large turbo + Manifold + ALL components
  • Best for: Stock setups, complete overhauls, wanting perfectly matched system
  • You get: Both turbos optimally sized to work together
  • Cost: $4,500-7,500

Add-A-Turbo Kit:

  • Includes: ONLY large turbo + piping/mounting (you use your existing turbo as small turbo)
  • Best for: Owners with upgraded single turbo who want to convert to compounds
  • You supply: Your existing turbo becomes the small turbo
  • Cost: $2,500-4,500 (lower because you're not buying small turbo)

Which should you choose?

  • Complete Kit if: You have stock turbo, want best-matched system, prefer turn-key solution
  • Add-A-Turbo if: You already have quality S300/S400/VGT turbo you want to keep

EVERYTHING for a twin-turbo compound system—both turbos and all components.

Complete kits include:

  • Small primary turbocharger: The first turbo (high-pressure) that mounts on manifold
  • Large secondary turbocharger: The second turbo (low-pressure) that mounts downstream
  • High-flow exhaust manifold: Upgraded manifold for small turbo
  • Turbo pedestal/adapter: Mounts small turbo to manifold
  • Large turbo mounting bracket: Secures large turbo to chassis
  • Complete intercooler piping: Small turbo → large turbo → intercooler (all piping)
  • Oil lines for both turbos: Feed and drain lines with proper fittings
  • Downpipe: Connects small turbo outlet to large turbo inlet
  • All gaskets, O-rings, seals
  • Complete hardware kit: Every bolt, stud, clamp, coupler
  • Air filter adapter: Connects to large turbo inlet
  • Detailed installation instructions with photos

What you'll need (not included):

  • Upgraded intercooler (large core for compound airflow)
  • Exhaust from large turbo to tailpipe (4" or 5" turbo-back)
  • Compound-specific ECM tuning
  • Supporting mods based on power goals

Why complete kits are best: No guessing at turbo sizing compatibility, no hunting for parts, no mismatched components. Everything is engineered to work together perfectly.

#1 RATED COMPOUND TURBO KITS - FREE SHIPPING ON ORDERS OVER $300 - MADE IN THE USA - BACKED BY INDUSTRY LEADING ENGINEERING - SHOP WITH CONFIDENCE -