How does the driver switch tune profiles at a sled pull event?

EFI Live uses a DSP5 switch — a 5-position rotary switch mounted in the cab that allows selecting between stored calibration profiles without a laptop. This truck uses positions 1 (street), 2 (tow), and 3 (pull). No laptop required at the track.

Can I build a similar compound Cummins for street use without competition setup?

Yes. The S300/S400 compound for street and tow use without trans brake and competition tune is a common build path, producing 550-650 rwhp and 900-1,000 lb-ft on a street profile at lower total cost.

Why rebuild the 68RFE instead of converting to an Aisin for competition?

An Aisin retrofit on a 68RFE truck requires driveline modification and is not a bolt-in swap. For existing 68RFE trucks, a purpose-built competition rebuild with upgraded converter, clutch pack, valve body, and trans brake is the correct path.

2018 Ram 2500 6.7 Cummins sled pull build Houston Drop Forged Diesel

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Build Showcase · Houston, TX

2018 RAM 2500
6.7 CUMMINS
HOT STREET
SLED PULL

Q: Why S480 primary instead of a larger turbo for Hot Street sled pull?

Hot Street class rules cap turbo inducer size. The S480 80mm primary is the largest that fits the class while producing top-end flow for the 1,100+ lb-ft fueling target. A larger primary would exceed class-legal A/R ratio limits.

Vehicle

2018 Ram 2500

Engine

6.7L Cummins

Class

Hot Street

Output

712 RWHP

Torque

1,188 LB-FT

Build Story

FROM DAILY DRIVER
TO HOT STREET.

This 2018 Ram 2500 came in as a daily driver and tow truck with a Stage 1 tune already on it from another shop. The owner had been running regional sled pull events in the Work Stock class and wanted to move up to Hot Street — which meant a complete rebuild of the fuel system, turbo configuration, and transmission.

The 2018 is a CP3 platform, which simplified the fuel system conversation. No conversion needed — we upgraded the lift pump to a FASS 220 to support the S300/S480 compound fueling demand, added high-flow injectors, and rebuilt the 68RFE with a trans brake valve body and upgraded clutch pack.

The compound turbo configuration was an S300 secondary and S480 primary — a configuration that spools quickly from the 60-foot while producing enough high-end airflow to support the 1,100+ lb-ft fueling target at the hook. EFI Live was used for the competition calibration alongside a separate daily-drive street tune stored as a second profile.

The truck drives to events on the street tune, switches to the pull profile at the staging lane, competes, and drives home. It also still pulls the owner's gooseneck on the tow profile — the same truck, three calibrations. See the sled pull prep page for how we build competition trucks and the Ram 2500/3500 page for the full platform build path.

2018 Ram 2500 6.7 Cummins S300 S480 compound turbo installed

Build Context

The owner drives this truck to work Monday through Friday on the street tune. Pulls gooseneck on weekends on the tow tune. Competes in Hot Street on the pull tune. Same truck, three calibrations. Total build time was 5 weeks including trans rebuild.

Full Build Sheet

Every Component on This Build

Complete parts list — what was installed, what was upgraded, and what carried over from stock.

FUEL SYSTEM

Lift PumpFASS 220 Titanium Series — frame-mounted
Injection PumpStock CP3 — 2018 MY, no conversion required
InjectorsIndustrial Injection 60% over — stage-matched to compound output
Fuel LinesUpgraded supply lines — FASS to CP3
Fuel FilterFASS integrated water separator + pre-filter

TURBO SYSTEM

PrimaryS480 — 80mm inducer, 1.10 A/R turbine housing
SecondaryS300 — 64mm inducer, fast spool configuration
Compound KitIndustrial Injection compound turbo manifold + mounting hardware
IntercoolerS&B large core intercooler — high-flow end tanks
Cold Side3" intercooler piping — silicone couplers

TRANSMISSION

Platform68RFE — full competition rebuild
ConverterUpgraded triple-disc torque converter — stall increase
Clutch PackHeavy-duty clutch pack — rated for competition torque
Valve BodyTrans brake valve body — competition hookup launch
ServoIncreased apply pressure servo — 2nd gear hold

CALIBRATION

PlatformEFI Live — multi-file, 3 calibration profiles
Street TuneStage 3 street/daily profile — driveability + tow
Tow TuneGooseneck tow profile — EGT management + torque floor
Pull TuneHot Street competition profile — class-specific fueling curve
VerifiedChassis dyno — 712 rwhp / 1,188 lb-ft confirmed

Verified Results

Dyno-Verified Output — Pull Tune Profile

All figures verified on chassis dyno at Drop Forged Diesel using the competition pull tune profile.

Wheel Horsepower 712 rwhp on pull tune · up from 325 stock

Wheel Torque 1,188 lb-ft on pull tune · up from 620 stock

Build Time 5 WK Consultation to delivery including trans rebuild

Tune Profiles 3 Street · Tow · Pull — driver-selectable

Build Photos

In-Process & Finished

Ram 2500 S300 S480 compound turbo installed overhead view

68RFE transmission rebuild competition trans brake valve body

Ram 2500 Cummins sled pull build on chassis dyno Houston

Build Questions

About This Build

Questions we heard on this specific build and the answers behind them.

Why S480 primary instead of a larger turbo for Hot Street?+

Hot Street class rules at the events this truck competes in cap turbo inducer size. The S480 80mm primary is the largest that fits the class while still producing top-end flow for the 1,100+ lb-ft fueling target. A larger primary (S500 range) would produce more peak flow but would push the A/R ratio out of the class-legal range. The S300 secondary was chosen specifically for its fast spool — it fills in the low-RPM range before the S480 comes fully on.

Why rebuild the 68RFE instead of converting to an Aisin?+

The 2018 Ram 2500 came from the factory with a 68RFE — an Aisin retrofit would require driveline modification and is not a bolt-in swap. For trucks that come in with a 68RFE, a purpose-built competition rebuild with upgraded converter, clutch pack, valve body, and trans brake is the correct path. Had this truck been ordered new with competition use in mind from day one, we'd have recommended speccing the Aisin. For existing trucks, we build what's there.

How does the driver switch between tune profiles at an event?+

EFI Live uses a DSP5 switch — a 5-position rotary switch mounted in the cab that allows the driver to select between up to five stored calibration profiles without a laptop. This truck uses positions 1 (street), 2 (tow), and 3 (pull). The driver turns the switch to position 3 at the staging lane. The ECM loads the pull calibration immediately. After the event, back to position 1 for the drive home. No laptop required at the track.

Can I build a similar truck for street use without the competition setup?+

Yes — the S300/S400 compound for street and tow use without the trans brake and competition tune is a common build path. The street compound build produces 550–650 rwhp and 900–1,000 lb-ft on a street profile. The trans brake and competition tune are specific to pull class use. A street compound build can be done without them at a lower total cost. See the compound turbo build page for the street compound configuration options and the fuel system page for lift pump detail.