Hondata Reflash - Civic Si 2006-2011

Reflash your 2006-2011 Civic Si engine computer - this reflash is for the US and Mexican 2006-2011 Civic Si with K20Z3 engine.

• Fuel, ignition and cam timing optimized.
• VTEC lowered from 5800 rpm to 4500 rpm.
• VTEC window added.
• Cam angle optimized.
• Rev limiter increased to 8600 rpm
• California emissions legal (CARB EO D-742)

This is for an ECU reflash - the ECU is not included.  Hondata does not sell direct - the reflash must be purchased from a Hondata dealer. The ECU reflash form must be sent with your ECU.

Important Notes

This reflash will work well with a variety of aftermarket performance parts. It will work well with:

• An intake
• Cat-backs (as long as they are less restrictive than stock)
• A race header *
• A combination of intake and race header

(*Note that current race headers eliminate the catalytic converter and will generate a check engine light. This engine check light is for emissions and will not affect the car's performance. Race headers are for off road use only)

You must have a minimum of an intake or header.

It is not designed to work with a stock 2006-2011 Civic Si and will lose power between 4500rpm and 5600 rpm if installed.

Intakes

The 06 Civic employs a mass air flow sensor that automatically adjusts the air-fuel ratio for increases in air flow from correctly designed intakes and race headers. Intakes for this car are critical. The intake, in particular the size and shape of the piping around the mass air flow sensor, is the primary determinant of fueling for this car. If you have any problems in running rich or lean, then you must retest with the stock intake. Race headers will not cause this engine to run lean.

For consistency in dyno testing we suggest you follow the dyno procedure outlined here.

Power is gained in the mid range from 4700rpm to 6300 rpm. Power gains above 6500 rpm are negligible, although the higher rev limit will raise average power a little.

As this reflash will work with a combination of aftermarket parts we have two examples of the effect of the same reflash on two 06 Civics. (Both Civics dynoed at about 195 stock HP)

2006 Civic Si with Race header, intake and Hondata Heatshield gasket.

• 4500 rpm VTEC point
• Rev limiter raised to 8600 rpm.
• 15-25 Hp gain midrange
• 15-29 ft lb torque gain midrange

2006 Civic Si with intake and Hondata Heatshield gasket.

• 4500 rpm VTEC point
• Rev limiter raised to 8600 rpm.
• 10-15 Hp gain midrange
• 5-12 ft lb torque gain midrange

The ECU is located under a plastic cover to the right of the battery under the hood. You will need a 10mm socket. This is what it looks like - in place and removed from the car.  There are 3 bolts holding the ecu in.  You may find it easier to completely remove the battery, but you will need to enter the codes for your radio if you do this.
 

VTEC Window

We have implemented a VTEC window from 4500rpm to 5800 rpm.

• Below 4500 rpm the K20Z3 is always on the low cam
• Above 5800 rpm the K20Z3 is always on the high cam
• Between 4500 rpm and 5800 rpm the K20Z3 is on the low cam at part throttle switching to the high cam at full throttle.

The VTEC switch point on this reflash is very smooth - much smoother than previous reflashes. With a stock air box and race header the switch point is virtually undetectable. For the reduction in VTEC "kick" and aural stimulation, we apologize, but this is the path to maximum power.

Nitrous

Nitrous has not been tested. As ignition timing has not been changed, nitrous is as safe to run with this reflash as with a stock ECU.

Cams

Aftermarket cams have not been tested.

Race headers

Race header / test pipes will eventually give you an engine check light telling you that you have a faulty catalytic converter. Race headers are for off road use only.