1994 Mazda RX7 | Custom Engine Wiring Harness & Link G4X Module Installation

This week, we've had this awesome Mazda RX7 in our workshop, for the installation & manufacturing of a bespoke engine wiring harness, a Link G4X module installation & some dashboard gauges for good measure. Here's how we did it...


  • The 3rd generation RX7 is famous for being the first ever mass produced vehicle to be exported from Japan that featured a sequential twin turbocharger system. One turbocharger provides 0.69 bar (10 psi) of boost from 1,800 - 4,000 RPM, with the second turbo changeover activating at 4,500 RPM, and providing identical boost pressure as the first turbo - until redline. 

RX7 Link G4x ecu installation and wiring harness front of redline tuning

  • Those who purchased the 3rd RX7 before 1993 in the UK were refunded a whopping £7,000 when Mazda officially reduced the price of the car in the following year, in an attempt to boost sales. The majority of RX7's we see are imported directly from Japan, due to sluggish UK sales.
  • Coupled with the worldwide success of the Fast and Furious film franchise, the RX7 has achieved cult tuner status, with the 13B rotary engine capable of comfortably reaching double it's power output with a couple of well-thought out modifications.

rx7 link g4x ecu installation with custom wiring engine harness at redline tuning

  • This particular example is no different. Thanks to a complete engine rebuild / overhaul by our friends at Lightning Motorsport, this RX7 was ready for a custom remap. However, before this was to happen, Redline were drafted in to create a bespoke engine wiring harness for a Link G4X ECU Module...

Engine Wiring Harness & Link G4X Install.

  • In order to render the Link G4X module usable, a custom engine wiring harness was specifically crafted for this RX7. Think of the wiring harness as the "veins" feeding electricity to all the vehicle components that need powering - including fuel injectors, wiper motors & the Link Module itself. Take a look below:

rx7 rotary bespoke wiring engine harness by redline tuning


  • Once built, it's securely installed, ready for the Link G4X Module installation. Link ECU's are a popular choice not only for retro Japanese cult cars such as the RX7, but across the board. Link ECU's are typically able to replace stock ECU's to perform most of the functions that both the tuner & client want - boost control, anti-lag, launch control capability & even powering race dashes - to name a few. This is sole reason why Redline are an authorised Link Dealership.
  • Once the custom harness & the Link ECU were installed, it was onto our Dyno to create a base map. This is a fundamental step for running the newly built engine in. Creating a performance map at this stage runs the risk of catastrophic engine failure - you're not running a marathon 6 weeks after breaking a leg; the same principle applies to new engine builds.


The Results.

  • No results as yet - this RX7 is back with us in the coming months for a full custom tune on our in-house Dyno Dynamics rolling road. Be sure to check back once it's run in, we're expecting a great result...!

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