Texas Speed Chopacabra

Chopacabra Remote Tune

A custom JR Jones Racing tune built around your Texas Speed Chopacabra cam swap — not a generic file, a calibration matched to your actual vehicle and build.

The Chopacabra's bigger overlap changes idle vacuum, exhaust signal, and throttle behavior enough to confuse a stock calibration. JRJ tunes from your stock read file and rebuilds idle, throttle response, and drivability around the cam, transmission, converter, fuel system, and every supporting mod you send.

Build My Tune
  • Personally Tuned by Jason
  • Revisions Included
  • Secure Tune Portal
  • Built From Your Factory Read File

Build Your Tune

Select your vehicle, camshaft, and modifications so JR Jones Racing can build the correct remote tune package.

Build Your Tune Package
Verified Vehicle Match
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The MPVI4 is the interface used to read, license, flash, and log supported vehicles with HP Tuners.

$419.99

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Choose year, make, model, engine, and cam selection.
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Instant Download Option

Prefer a Downloadable .HPT File?

Browse compatible pre-built HP Tuners files for this vehicle or modification. Always verify the ECM, operating system, engine, transmission, fuel type, and modifications before purchasing.

  • 1999–2006 GM Gen III 5.3L Texas Speed Chopacabra Cam Tune File

    1999–2006 GM Gen III 5.3L Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
  • 2009–2018 5.7L HEMI Texas Speed Chopacabra Cam Tune File

    2009–2018 5.7L HEMI Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
  • 2007–2013 GM Gen IV 6.2L Texas Speed Chopacabra Cam Tune File

    2007–2013 GM Gen IV 6.2L Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
  • 1999–2006 GM Gen III 4.8L Texas Speed Chopacabra Cam Tune File

    1999–2006 GM Gen III 4.8L Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
  • 2013 Chevrolet Silverado 5.3L BTR Truck Norris Cam Tune File downloadable HP Tuners HPT file

    2013 Chevrolet Silverado 5.3L Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
  • 2013 Chevrolet Silverado 5.3L BTR Truck Norris Cam Tune File downloadable HP Tuners HPT file

    2012 Chevrolet Silverado 5.3L Texas Speed Chopacabra Cam Tune File

    $99.99
    VIEW & BUY →
View All 11 Compatible Files →

1. What This Page Is For

Chopacabra Cam Tuning Starts With The Whole Build

This page is for customers running or planning a Chopacabra cam setup. The tune depends on the vehicle, engine, controller, transmission, converter, headers, injectors, delete hardware, and tuning device.

The cam name alone is not enough. JRJ needs real build details so startup, idle, airflow, fueling, torque model, and drivability changes match the vehicle instead of a generic cam label.

Send cam card/specs before tuning.

Device requirement: Reading and flashing your vehicle requires an HP Tuners MPVI2, MPVI3, or MPVI4, or a supported EFI Live device. RTD and TDN devices will not work unless issued directly by JR Jones Racing.

2. Supported Platforms

Where Chopacabra Tune Support Fits

Use the builder or matching product page when you are unsure. HEMI support is shown because the current builder includes a Texas Speed Chopacabra HEMI selection where supported.

Texas Speed Chopacabra camshaft — 1999-2006 GM Gen IIIGM Gen III LS

1999-2006

LS1, LM7, LQ4, LQ9 truck and LS-style builds. No factory AFM/DOD on most.

Texas Speed Chopacabra camshaft — 2007-2013 GM Gen IVGM Gen IV LS

2007-2013

5.3, 6.0, and 6.2 trucks/SUVs. DOD/AFM and VVT status may apply.

Texas Speed Chopacabra camshaft — 2014-2018 GM Gen VGM Gen V LT

2014-2018

L83 and L86 builds need AFM, VVT/cam phaser, and torque model details.

LS3 / L99 / LT1 camshaft — Camaro / CorvetteCamaro / Corvette

LS3, L99, LT1

Manual vs automatic matters. L99 has AFM/DOD considerations.

Texas Speed Chopacabra and BTR Truck Norris camshafts — 2009-2012 HEMIHEMI Platforms

2009-2012

5.7 and 6.1 HEMI support depends on vehicle, controller, and MDS/VVT status.

Texas Speed Chopacabra and BTR Truck Norris camshafts — 2013-2018 HEMIHEMI Platforms

2013-2018

5.7 and 6.4 HEMI support depends on vehicle, controller, and MDS/VVT status.

Texas Speed Chopacabra and BTR Truck Norris camshafts — 2019 and up HEMIHEMI Platforms

2019 & Up

5.7 and 6.4 HEMI support depends on vehicle, controller, and MDS/VVT status.

3. Chopacabra Setup Checklist

Details JRJ Needs Before Building The File

Engine
Cam specs / cam card
Converter
Headers / manifolds
Injectors
Throttle body / intake
Gear ratio
Tire size
Transmission type
DOD / AFM / MDS / VVT
Stock read file
Calibration screenshot

4. Tune Changes JRJ May Address

Calibration Areas That Matter On A Cammed Build

Every vehicle is different. These are common areas JRJ may address when the vehicle, controller, and uploaded file support it.

Startup And Idle

  • Idle airflow
  • Idle spark
  • Startup airflow
  • Throttle cracker and follower

Fuel And Airflow

  • MAF/VE airflow modeling
  • Injector data
  • Fuel trim direction
  • MAP and intake details

Drivability

  • Gen V torque model where supported
  • Transmission behavior
  • Converter behavior
  • Fan settings

Support Items

  • Rear O2/catalyst support
  • Speedometer correction
  • Gear and tire changes
  • Customer feedback and logs

5. Supporting Mods Decision Guide

What Changes The Tune Path

Stock Converter

Tell JRJ it is stock so idle-in-gear expectations are realistic. Automatic cars may still need logs.

Aftermarket Converter

Send stall, brand, part number, transmission type, and current behavior.

Long Tube Headers

Send header, catalyst, rear O2, current code, and exhaust details.

DOD / AFM Delete

Use the delete tune path when hardware has been changed. Include VVT status.

MDS Delete

HEMI builds need MDS hardware status and the matching supported tune path.

VVT Retained

Tell JRJ whether VVT is retained and send the cam card/specs before tuning.

VVT Limited / Deleted

Include phaser limiter, lockout, or delete details. The tune must match the hardware.

Bigger Injectors

Injector data or exact part number is required. Guessing injector data causes problems.

Gear / Tire Changes

Send axle ratio and tire size for speedometer and transmission behavior support.

Transmission Tune

Use a compatible transmission tune add-on when shift behavior or converter support is needed.

6. Common Problems After A Chopacabra Cam Swap

Symptoms JRJ Can Help Diagnose

The Texas Speed Chopacabra is a strong all-around truck and car cam, but its bigger overlap still changes idle vacuum, exhaust signal, and throttle behavior enough to confuse a stock calibration. Tuning fixes the calibration side — mechanical issues (vacuum leaks, bad connections, worn parts) still need to be corrected mechanically first. Send logs when available so we can tell the difference.

Starts Then Dies

The Chopacabra's idle vacuum signature doesn't match what the factory startup fuel and airflow tables expect, so the ECM under- or over-fuels right after cold start. We rebuild those tables around the cam's real signature. Send the stock read and a startup log.

Stalls Into Gear

Lower idle vacuum can load the torque converter down the moment you shift into Drive if idle airflow and converter behavior weren't recalibrated for the cam. Send converter, idle airflow, and transmission details so we can raise idle support correctly.

Idle Surge / Hunting

A rougher idle signal can confuse closed-loop idle control, causing RPM to hunt instead of settle. Send cam card/specs, intake, MAF, injector data, and an idle log so we can match the airflow and spark tables to the real cam.

Slow Throttle Return

More overlap changes low-throttle airflow behavior, which can leave the throttle blade hanging open slightly on deceleration — especially common on cammed Gen V builds. Send drive logs describing when it happens.

Rich / Lean Trims

Higher idle airflow shifts where the engine sits on the factory VE table, and injector data, MAF placement, or an exhaust leak can compound it. Send injector info, current trims, and logs so we can correct the airflow model.

Poor Shift Feel

Shift scheduling and line pressure are calibrated for the stock powerband, so adding a cam (often with a gear or tire change too) throws shift feel off until those tables are rematched. Send transmission type, gear ratio, tire size, and converter info.

Converter Lockup / Stall Behavior

Lower idle vacuum can trip factory lockup and unlock thresholds earlier or later than intended, causing shudder or flare at cruise. Send stall speed, lockup behavior, and how the vehicle is driven or towed.

Rear O2 / Catalyst Codes

Header and catalyst swaps are common alongside a Chopacabra install, and they change exhaust routing and O2 sensor placement versus stock. Send current codes and full exhaust details so we can match the monitor thresholds.

Speedometer Reading Wrong

Gear and tire size changes that often come with a cam swap throw off the factory speed calculation unless the real axle ratio and tire diameter are entered into the calibration.

Fan Settings Off

A built engine carries a different heat load than stock. Send thermostat rating, fan/radiator setup, and target behavior so we can correct the on/off setpoints.

8. What To Send JRJ

Upload Checklist

  • Stock read file
  • Calibration details screenshot
  • VIN
  • Year / make / model
  • Engine
  • Transmission
  • Cam card/specs
  • Converter
  • Injectors
  • Headers / cats
  • Gear ratio
  • Tire size
  • DOD / AFM / MDS / VVT status
  • Current codes
  • Logs if available

Upload Flow

Purchase First, Then Upload

After checkout, your private upload portal link is emailed to the checkout email address. Use that portal to send your stock read file, build notes, screenshots, logs, and revision feedback.

Includes your first revision. Most first custom tunes are completed within 24 business hours (Monday–Friday). Most revisions are completed within 24 business hours. During busy periods, turnaround may take up to 48 business hours.

Why Choose JR Jones Racing

Built By One Tuner. Tuned Around Your Vehicle.

Every JR Jones Racing tune is personally built by Jason from your vehicle's own stock read file — not a pre-canned upload matched to a cam name.

1:1
Personally Tuned

Every file is built by Jason, not a queue of random tuners.

HPT
HP Tuners Expert

Deep HP Tuners and EFI Live workflow experience.

1st
Revision Included

Your first revision is included with every tune file.

24hr
Hour Turnaround

Most first tunes and revisions are completed within 24 business hours — up to 48 during busy periods.

100%
Built From Your File

Every calibration starts from your own factory read, not a generic base.

Customer Reviews

Trusted By Real Customers

"Idle, startup, and throttle response were all cleaned up."

— T.C. • 2002 Camaro LS1 Cam Tune File
Before You Order

Have This Ready Before You Buy

  • Confirm your exact year, make, model, and engine
  • Know your DOD / AFM / MDS / VVT hardware status
  • Have your cam card or cam specs on hand
  • Confirm HP Tuners or EFI Live hardware access
  • List every supporting modification (headers, injectors, converter, gear, tire size)

10. FAQ

Chopacabra Cam Tune Questions

Can JRJ tune a Chopacabra cam?

Yes, JRJ supports Chopacabra cam tune workflows where the vehicle, controller, tuning device, and stock read are supported. Send cam card/specs before tuning.

Do I need a converter?

It depends on the vehicle, transmission, cam setup, and drivability expectations. If an aftermarket converter is installed, send stall, brand, and part details.

Can this work with stock manifolds?

Many builds can be tuned with stock manifolds when the rest of the setup is supported. Send the full build details so the file matches the vehicle.

Do I need long tube headers?

Long tube headers are not required for every tune path, but if they are installed JRJ needs header, catalyst, rear O2, and current code details.

Does DOD/AFM/MDS need to be deleted?

That depends on platform, cam choice, and hardware. The tune must match the actual DOD, AFM, MDS, and VVT hardware status.

What if I do not know my VVT setup?

Use the tune builder and check your VIN/RPO details to confirm the setup before ordering. VVT retained, limited, locked, or deleted setups need different notes.

Do I need HP Tuners credits?

You need an HP Tuners MPVI2, MPVI3, or MPVI4, or a supported EFI Live device to read and flash your vehicle — RTD and TDN devices will not work unless issued directly by JR Jones Racing. HP Tuners credits are sold separately unless a specific bundle clearly says otherwise.

What file do I send after purchase?

Send the clean stock read file through your private upload portal, along with vehicle details, cam card/specs, mod list, screenshots, and logs if available.

Can JRJ review stalling after the cam swap?

JRJ can review calibration-related startup, idle, and drivability issues where the vehicle is supported. Mechanical problems still need to be fixed mechanically.

Built A Beast. Now Tune It Right.

Get the most out of your Chopacabra cam with a tune built around your exact vehicle, file, and setup.

Build My Tune