Flex
FLEX Monoblock DMAX / MUX Intercooler - (2012-2019)
FLEX Monoblock DMAX / MUX Intercooler - (2012-2019)
Taxes included. Shipping calculated at checkout.
Couldn't load pickup availability
Isuzu 4JJ1 | Drop-In Replacement | 605 x 255 x 65 mm Core | Tested to 100 PSI | Suits F44 and F55 Builds
The factory D-Max / MU-X intercooler is the restriction on a tuned 4JJ1. The Flex monoblock replaces it in the factory location with a roughly 605 x 255 x 65 mm core, no cutting, drilling or welding, and runs on the factory 2.5 inch intercooler pipes.
Tested to 100 psi, it is the intercooler for F44 and F55 low-mount builds and other aftermarket turbo setups that need charge temps kept in check under sustained load. Stronger, more repeatable power on road, towing or at the track.
What Is Included
- Flex monoblock intercooler assembly
Direct fit using the factory mounting hardware and the factory 2.5 inch intercooler pipes. No piping or clamps are included.
Key Benefits
- Much larger surface area than factory for superior heat rejection
- Monoblock construction for durability and efficient airflow
- Supports high-boost builds: tested to 100 psi
- A match for F44 and F55 turbos and other aftermarket setups
- No fabrication required: mounts to the factory location
- Suits the factory 2.5 inch inlet and outlet pipes
Specifications
| Vehicle platform | Isuzu D-Max / MU-X (Gen 2), 2012 to 2020 |
| Engine | 4JJ1 |
| Core size (approx.) | 605 x 255 x 65 mm |
| Boost capability | Tested to 100 psi |
| Inlet / outlet | 2.5 inch (factory pipes) |
| Install | Direct bolt-in, no cutting, drilling or welding |
Vehicle Fitment
- Isuzu D-Max 2012 to 2020 (4JJ1)
- Isuzu MU-X 2013 to 2020 (4JJ1)
Designed to work with the factory 2.5 inch intercooler piping. If you are running custom piping, confirm coupler sizing before install.
Fitting Notes
- Fits the factory location and connects to the factory 2.5 inch intercooler pipes.
- Always test-fit, then re-torque the clamps after a heat cycle.
- Performance gains depend on tune, turbo, ambient temps and load. An intercooler does not add power on its own; it lets the tune and turbo hold power by controlling intake temps.
Supporting Hardware
Building a turbo 4JJ1? Pair the intercooler with the 4JJ1/4JJ3 stainless exhaust manifold for F44/F55 turbos.
Stock and Lead Time
Generally in stock. If sold out, allow around 1 to 3 weeks for dispatch. For urgent timelines, message us before ordering.
Shipping and Payment
Free express shipping Australia-wide with tracking.
Afterpay, Humm, Klarna and Zip accepted at checkout. Returns and warranty are covered by our refund policy.
Frequently Asked Questions
Will this work with my F44 or F55 turbo?
Yes. This intercooler is designed to support the popular D-Max / MU-X upgrade paths including low-mount F44 and F55 turbos, keeping intake temps in check under sustained load.
Do I need to modify anything?
No. It fits the factory location and connects to the factory 2.5 inch intercooler pipes. Always test-fit and re-torque the clamps after a heat cycle.
How much power will I gain?
Intercoolers do not add power by themselves. They let your tune and turbo hold power longer by controlling intake temps. Expect improved consistency when towing or in hot conditions.
100 PSI Tested. Drop-In Fit.
Flex monoblock intercooler for the 2012 to 2020 4JJ1 D-Max and MU-X. Free express shipping Australia-wide.
Common Rail Cowboys is not affiliated with Isuzu Motors. Flex is a trademark of its owner and is used here to identify the product. The 100 psi figure is the manufacturer's test rating; safe operating boost depends on the complete installation. Installation should be carried out by a competent person. Confirm fitment for your vehicle before ordering; fitment is the buyer's responsibility. Modifications may affect vehicle warranty and compliance.
