Hondata S300J V3 (for JDM ECUs only)

Hondata S300J V3 (for JDM ECUs only)


(£458.33 ex VAT)

In stock

Product Information

The only definitive way to get the most from any engine modifications you have made (such as air intake systems, exhaust systems, camshafts, supercharger, turbo etc) is to have the electronic control unit (ECU) in your car professionally tuned/mapped on a dyno with a Hondata engine management system.

Hondata systems modify the standard Honda engine computers (ECUs), adding features and expanding the capabilities of the stock ECU. Vehicles with year of manufacture up to and including 2006 models require the ECU to be modified and in most cases hardware is added, for vehicles of years 2007 and onwards tuning takes place via an external programming interface. In all cases Hondata software is utilised in order to change the parameters/settings within the ECU (i.e. to tune the car).

So why use Hondata instead of one of the many standalone systems available on the market? The answer is very simple; nothing will run a Honda engine better than a Honda ECU, and the Hondata systems all leave the Honda ECU completely intact thereby retaining full reliability, full dash functionality etc.

Applications - Please see Technical Information section

The Hondata S300J converts the factory OBD1 Honda ECU into a fully reprogrammable engine management system. With an S300 system fitted the car can be tuned (remapped) on a dyno to release the untapped power in the engine. All levels of modification can benefit from an S300 system from a totally standard car, to a mildly modified setup, right through to the wildest supercharged, nitrous-injected or turbo setup.

• Fits inside the ECU
• Built in data-logging to a laptop
• Adjustment for different sized injectors, with overall fuel trim
• Configurable for any MAP sensor (to 5 Bar and above)
• TPS based table lookup for ITBs
• Engine protection from over boost and lean protection
• Expanded fuel and ignition tables, both in rpm and load, to 60 lbs boost and 11,000 rpm (these are not the upper limits)
• Three multi-purpose outputs for nitrous control or similar
• PWM output for boost control

In addition the new version of the S300J now on sale with immediate effect (version 3) has the following features:

- Bluetooth
- Mobile device compatibility
- Ethanol sensor compatibility,
- Aftermarket dash Compatibility
- Serial output
- CAN output

Please note: If you would like CPL Racing to socket your OBD1 ECU and fit the S300J for you, please purchase the S300Jv3 and socketing/fitting (listed as separate item on Hondata product pages on our website). Please also request an order form from to send with your ECU.

Further note: This S300Jv3 is only suitable for the "square" JDM ECUs, if you have either a European or US ECU you will need an S300v3, please see separate item listed on our website.

To find out more about Hondata, please see this link

Category: Engine Management

Vehicle Fitment Information

All fitment information is only a guide, exact fitment may differ. If in doubt please email us.

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  • Full on-site dyno tuning service
  • ECU testing

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