Has anyone changed the VTEC sender to turn on VTEC at say 5500 rpm instead of the factory setting? If so what is your experiance?
BTW what is the factory set point? Mine starts at about 7000 rpm and that seems quite high.

 

this would be cool, what would be the neg points of moving it to lets say 4,000?

 

If yours kicks in at 7k, you should get that looked at, because it's supposed to kick in around 6k. As for lowering the point, I can think of 2 potential problems if done incorrectly. The engine can be starving for fuel at the lower rpms if VTEC is engaged, since at high rpms the fuel mixture is rich. Also, you could also sacrifice some torque at those lower rpms...this is just my (un)educated guess.

 

4000 RPM and you will feel no VTEC back until stock levels if you just change the VTEC setpoint without other modifications, 5500 RPM will do a bit of feel until your ECU finally decides to think smart and activate the malfunction light. Your VTEC solenoid will also fail due to that thus causing VTEC cut-off to be much earlier.

To do this right, you should change the ECU to performance ECUs on the market. Spoon will be a good choice but to bring the car to past 10,000 RPM revs then engine work must be done otherwise it will die as well. Throttle body has to be widen, fuel pressure/air mix ratio has to be tuned accordingly as well. A simple application of a typical VTEC controller will only do more harm instead of anything good in the long run without proper modifications to compliment the new setup.

 

FWIW, the Mugen ECU does not change the VTEC engagement point.

 

Does anyone know if the stock tach is off? I know this is a common problem on other Hondas. On my tach, it's 6000 (indicated), I would say anything higher has a tach or VTEC pressure solenoid problem.

My experience with other Hondas has been that a V-AFC or other a/f/VTEC controller will change the switchover point w/o any problems or MIL/CELs. I'd be surprised if the S2k would- has anyone gotten a CEL for this?

Any a/f controller will allow for richening or leaning of the a/f ratio, though this will require a wideband O2 on a dyno for a/f tuning. The V-AFC will in addition allow for VTEC fuel correction at just the VTEC point (that overrides the other settings). I'm hesitant to hack the wiring harness on a $32k car. Does anyone know if our ECU is similar to other OBD2 Honda ECUs? If so, http://www.hondata.com and http://www.jdmhondaparts.com sell harnesses that you can hack instead of hacking the stock wiring (and allow you to turn the car back to stock easily).

On the topic of ECUs, the Spoon unit requires a core swap (or so their web site says). Has anyone purchased one? I would think that if they are modifying stock ECUs, they may be willing to do custom mapping or at least some custom settings. Since I'm not in Japan, though, and don't know Japanese, this may be a tall order

I would love to change the VTEC point. I don't think it will be a problem, I'm sure that oil pressure is high enough past 3500 or 4k rpms to engage it safely. I doubt, though, with the cam profiles, that it would buy anything below 5k. It's been my experience, though, that Honda likes to delay VTEC to make it feel punchier... I'd rather have it a little smoother (not to mention a little lower). My wager is that 5k may be closer to the "sweet spot" where you increase power/torque without any loss.

 

What visc oil are you running? With lighter oils you can loose VTEC on the track.

 

I've had my VTEC engagement set at 5600 RPM's (via V-AFC) for a while now with no problems. Anything lower than 5600 RPM's then the transition boggs a bit. I had mine tuned on a dyno and 5600 seems to be optimum.

 

To have a custom mapping setup done, the ECU has to be sent back to the factory with a full listing of all modifications or parts changed that are not stock that are used to determine the modifications outcome. This is effective but not cheap as a matter of fact for the job to be done perfectly, it does require more than one tuning to get it absolutely right. I doubt strongly that Spoon does custom orders on such project scale but Mine's Japan will as that is that ever acclaimed Mine's VX-ROM.

 

Takashi,

Do you know what Mine's charges for this service? Do you know of any company that supplies a re-programmable ECU that will connect to the factory wiring without cutting and splicing? Like the A'pexi units for the Integra and Civic? I would very much like the adjustability of a "standalone" computer, but want to keep the Honda wiring and sensors in place. I'm seriously considering the Mugen right now but would like to have it adjustable.

Thanks!