My friend owns a civic si and she was asking about my car. We started talking about Vtec and she said that she wanted to reflash the engine to make vtec kick in at 4000 rpm. I asked her if this really was possible and she said yes. I then asked why it wasnt set that way from the manufacture and she stated that it drastically cuts down in fuel effeciency.

Is there any truth to this and if so, why is it not as popular as, for example, adding a turbo?

 

hondata does make a reflash for the 2006 and up S2000. It raises the redline some and drops the vtec engagement point. It is realtively new but pretty popular it seems.

 

The Hondata reflash is awesome. There are two reflashes available. One for use with a header that lows Vtec engagement to 4400 rpm. You only hit Vtec @ this engine speed at wide open throttle. At partial throttle you are still on the small cam.

I have the reflash and have noticed no difference in fuel efficiency and much greater mid-range than stock. Vtec engagement is virtually seamless. I highly recommend it until Hondata releases the F-Pro.

 

dont just lower the engagement point just for lowering it, back in the day the best we have was a piggy back vafc(and being broke). what happen in the dyno was the tuner change the fuel curve and tried different engagement point and picked one that is most suited for my need. lower isn't always better, the vtec is oil pressure operated and it's depended on the rpm of the motor.

not sure about the newer plug and play reflash tho'(for the 06+)

 

Does the reflash hurt the car in any way?
if not,
Why isnt it setup this way through the manufacture?

 

recommend it as well, with my VAFC i gained 12 whp in midrange, was very nice!!

 

She can definitely do it because the civic's have the k20's which means I'm sure they can use k-pro which is fully programmable. I had k-pro on my old RSX and loved it

 

for the toda reflash - under normal driving conditions (non-WOT driving) the reflash gets better mileage. at WOT it may drop some in the 4.2k-6k rpm range because of the lower vtec. at WOT from 6+k rpm it will be better or the same. overall it will be the same to better.

for the stock reflash - mileage will be better.

turbo vs. n/a reflash - is apples and oranges, worlds apart in fuel and performance