The SPOOLOGIC SL-100-077 is a brand new, direct drop-in Stage 1 performance turbocharger for 1994-2002 Dodge Ram 2500 and 3500 trucks with the 5.9L Cummins — covering both the 1994-1998 12-Valve and 1998.5-2002 24-Valve applications. Built on the Holset HX35 platform — the same wastegated, fixed-geometry architecture as your factory turbo — upgraded with a larger 63.5/88/94mm billet compressor wheel, a bigger 76/64mm turbine, a ceramic-coated hot side, and your choice of compressor housing finish.

The 5.9L Cummins bottom end is famously overbuilt — stock rods and a stock block handle airflow and cylinder pressure well beyond what a factory turbo can feed them, which is exactly why the platform supports a Stage 1 upgrade this well. It’s the right turbo for owners who’ve moved past stock tuning or fueling and want real airflow and horsepower headroom out of the HX35 platform — not just a factory replacement.

? CUSTOM TUNING RECOMMENDED

Custom tuning is highly recommended to get the full potential out of this turbo. The SL-100-077 will physically bolt up and run on the factory tune (or factory fueling map on 12-Valve mechanical applications) because it’s built on the same Holset HX35 platform as your OEM turbo — but the factory calibration is written for the factory wheels. It does not know how to take advantage of the larger 63.5mm billet compressor, the 94mm extended-tip exducer, or the upgraded internals. You leave a meaningful amount of airflow, response, and top-end on the table running stock.

To unlock what this turbo was built to do, plan on a custom tune (24-Valve) or proper fueling adjustments (12-Valve P-pump/VE applications) from a qualified 5.9L Cummins tuner or diesel shop. SPOOLOGIC does not supply, write, sell, or assist with custom tunes — please line up your tuning or fueling shop before the install if you want the truck to perform the way this turbo was designed to.

Power Support

The SL-100-077 is built to cleanly support up to ~475-500 rwhp when paired with proper tuning, fueling, and supporting modifications. Remember: a turbo doesn’t make power on its own — tuning and fueling make power, and the turbo’s job is to support what the engine is producing. The Stage 1 is sized to keep up with mild-to-moderate tunes, larger injectors, and supporting mods without surging, choking, or overspeeding.

63.5/88/94mm Billet Compressor Wheel

The Stage 1 steps up to a much larger 63.5/88/94mm billet extended-tip compressor wheel with a 7+7 splitter blade design — a significant jump over the factory 52/83mm or 54/78-83mm HX35 wheel — for noticeably more airflow, stronger top-end power, and lower EGTs under sustained load.

• Inducer: 63.5mm
• Exducer: 88mm base / 94mm extended-tip outer diameter
• Blade design: 7+7 splitter blade
• Material: 5-axis CNC-machined forged billet aluminum
• Balance: High-speed VSR balanced as part of the complete CHRA assembly

76/64mm Turbine Wheel

Sized larger than the OE turbine on both sides to keep up with the airflow gains on the cold side. The 10-blade design is built for clean spool, strong mid-range, and proper drive pressure under a Stage 1 tune or fueling adjustment.

• Turbine inducer: 76mm
• Turbine exducer: 64mm
• Blade count: 10

Bulletproof Bottom End, Bulletproof Fuel System

Part of what makes the 5.9L Cummins such a strong Stage 1 candidate is what’s underneath the turbo. The factory 12-Valve and 24-Valve bottom end — block, crank, and rods — is known to handle airflow and cylinder pressure comfortably up to roughly 750 crank horsepower without modification, so a Stage 1 turbo upgrade isn’t fighting the rest of the engine for headroom. On common rail-adjacent 24-Valve trucks running the CP3 injection pump, the fuel system is just as overbuilt — one of the reasons the 5.9L holds up so well as power climbs. The turbo, tune, and fueling are the real ceiling on this platform, not the engine block.

Ceramic Coated Turbine Housing & Center Section

SPOOLOGIC ceramic coats both the turbine housing and the center section (CHRA) on the SL-100-077. This isn’t high-temp paint — it’s a true thermal barrier rated for the 1,600°F+ surface temperatures a diesel turbine sees under sustained load.

• Drops turbine housing surface temps 33-50% — far less radiant heat dumped into the engine bay, which protects wiring harnesses, oil lines, and hoses from long-term heat damage
• Reduces post-shutdown heat soak into the CHRA and bearing oil — the #1 cause of premature turbo failure is oil baking on the bearing journals after shutdown, and the coating interrupts the radiant feedback loop that causes it
• Retains exhaust energy in the gas stream — keeping heat in the exhaust where it belongs (driving the turbine wheel) instead of soaking into the housing
• Corrosion and thermal-fatigue resistant — cast iron scales, pits, and cracks over years of heat cycling; the ceramic barrier protects the housing and CHRA for the long haul

Upgraded Internals — Standard

Every SPOOLOGIC turbo is assembled with upgraded internal components that go beyond a basic factory-style replacement:

• Extreme duty journal bearings — premium bronze-alloy bearings machined to tighter tolerances with improved oil groove geometry, maintaining the precise oil film that keeps the turbo shaft centered at 100,000+ RPM — even under higher heat and shaft loads
• 360-degree thrust bearing — added strength and load capacity over the factory 270-degree bearing, better at handling boost-driven thrust loads
• Step gap seal rings — improved sealing performance, less blow-by past the CHRA
• High-speed VSR balancing — smooth, dependable operation and longer bearing life

Recommended Supporting Mods

The Stage 1 is built for trucks that have already taken at least the first step into the modified world. To get the most out of this turbo and keep everything running clean, we recommend:

• Tune or fueling adjustment — A custom tune on 24-Valve trucks, or fuel plate / governor spring adjustments on 12-Valve mechanical trucks, is the single biggest unlock for the SL-100-077’s larger compressor and turbine
• Larger injectors — Stock injectors will run out of fuel before the SL-100-077 runs out of breathing room. Stepping up to a moderately larger injector lets the turbo work and pushes peak power further
• Free-flowing exhaust — A larger exhaust and quality intake let the bigger turbine and compressor breathe both directions
• Boost and pyrometer gauges — Keep an eye on drive pressure and EGTs as the tune or fueling comes up so you can dial the setup in with confidence

Choose Your Finish

Use the dropdown above to select your compressor housing finish. The 63.5/88/94mm billet wheel, 76/64mm turbine, ceramic coating, and upgraded internals are standard on every variation.

Compressor Housing Finish

• Raw — bead-blasted satin natural aluminum finish; no coating, just clean bare metal
• Black — deep gloss black powder coat, baked-on and won’t chip or fade from heat cycling
• Red — high-gloss red powder coat, baked-on and won’t chip or fade from heat cycling

What’s Included

• 1 SPOOLOGIC Stage 1 HX35 Cummins turbocharger — brand new, VSR balanced, ceramic and powder coated
• 1 turbo flange gasket
• 1 turbo drain gasket
• Turbo drain line O-rings
• 2 inner oil feed line fitting O-rings
• 2 outer oil feed line fitting O-rings

Features

• Direct drop-in fit for 1994-1998 12-Valve and 1998.5-2002 24-Valve 5.9L Cummins trucks
• Built on the Holset HX35 platform — same as factory
• 63.5/88/94mm billet extended-tip compressor wheel, 7+7 splitter blade design
• 76/64mm 10-blade turbine wheel
• Sized to cleanly support up to ~475-500 rwhp with proper tuning, fueling, and supporting mods
• Ceramic coated turbine housing and center section — reduces under-hood heat and protects the CHRA from oil coking
• Raw, black, or red compressor housing finish
• Wastegated, fixed-geometry architecture — matches OEM
• Extreme duty journal bearings, 360-degree thrust bearing, step gap seal rings, VSR balanced
• Fits both 12-Valve (1994-1998) and 24-Valve (1998.5-2002) applications
• No core charge — ever
• Built brand new, never remanufactured

Fits 1994-2002 5.9L Cummins (HX35)

• 1994-1998 Dodge Ram 2500 / 3500 5.9L Cummins 12-Valve
• 1998.5-2002 Dodge Ram 2500 / 3500 5.9L Cummins 24-Valve

Turbo Applications

• Replaces factory Holset HX35 (1994-2002 5.9L 12-Valve and 24-Valve Cummins) — Stage 1 billet upgrade

Replaces Factory OEM Part Numbers

• 3592766
• 3592767
• 5017509AA
• R5017509AA
• BD1045758
• FPE-HX35-63-FMW

⚠ Not For Sale In California

Emissions Notice: Not CARB approved. Not legal for sale or use in the state of California.

1-Year Limited Warranty

Every SPOOLOGIC turbocharger is covered by a 1-Year Limited Warranty against defects in materials and workmanship from the date of purchase. Warranty coverage requires that the unit first be shipped back to SPOOLOGIC for inspection. If SPOOLOGIC determines the failure was caused by a defect in materials or workmanship, the turbocharger will be repaired or replaced at SPOOLOGIC’s discretion. Warranty does not cover damage from foreign object debris, oil starvation, contaminated oil, extended oil change intervals, over-boosting, over-fueling, tuning beyond the turbo’s rated operating range, improper installation, use outside the listed fitment, cosmetic wear, coating discoloration, or normal heat cycling marks. Warranty does not cover labor, shipping, towing, downtime, or any other costs outside the turbocharger itself.