Raise Vtec point to increase FE?

[MrChoi]

Has anyone ever wondered if raising the vtec point will increase FE? i currently own an HX and vtec kicks in at 2500 prm which is about 62mph. i usually cruise around 65mph and was wondering if going into two intake valve vtec decreases fuel economy. if it does how about raising the vtec point or eliminate it completely?

just a thought, what you guys think?

[MrChoi]

thanks for the reply but that wasnt the question.

Originally Posted by theclencher

stay under 62.

[monroe74]

I don't know how you would go about doing that. What's needed is to reprogram the ECU, but I don't know of any way to do that.

Then again, I suppose you could turn off VTEC entirely, by unplugging the solenoid. Or you could put a switch in the circuit.

Then you could do some testing and find out how much money you save. Or whether it's too annoying to live without the extra power.

If you do this, let us know what you find out!

[MrChoi]

you can buy a simple unit to controll when vtec is engaged it "piggy back" on the cars ecu. i might jus try eliminating vtec and see if the lack of power will do anything.

[monroe74]

I know a simple switch can be used to defeat VTEC entirely, or turn it on and off manually. Other than that, I wonder what kind of control you're describing.

[dkjones96]

2500 rpm? Seriously? I guess it's because I've only dealt with newer engines but All the hondas I've dealt with go to VTEC way higher than that.

The 3.2 V6 is about 4500 and the S2000 and Civic Si engines are closer to 5750.

[monroe74]

"All the hondas I've dealt with go to VTEC way higher than that."

You're correct, but that's because we're talking about two different kinds of VTEC. This thread is about VTEC-E, found on the VX and HX.

VTEC-E is about economy, and it means the 2nd intake valve is mostly closed under 2500 RPM.

You're thinking of the more common Honda VTEC, which is about performance. At high RPMs, a different cam shape is used.

Two different animals.

[mkiVX]

http://www.inlinefour.com/spoonvteccon.html
http://urbanimport.stores.yahoo.net/rstyvtco.html
vtec controller YO
the problem is will lean burn still shut when vtec hits or will it be blind and still keep leaning. one thing is controlling the signal to the cam and one thing is the fuel map. some one do this and i will jump on the bandwagon. i climb a hill every day 600ft to 4200 elevation every day. you have no idea how hard it is to keep this in lean burn

[thehatchninja]

a VAFC, or chipped ECU would do it. I know people that have used a VAFC to move their VTEC engagement for road trips.

[GasSavers_Ryland]

You could also swap a VX/CX tranny in to your car to lower the highway RPMs to around 2,000 at 65mph, this would keep the 4th valve from opening as well as lowering your over all engine speed.