Interesting Vtec crossover info

[D1sclaimer]

On my way home from work, I was experimenting with how Vtec works by using my AFC Neo(newer VAFC). I was using the Vtec monitor on it to show when it kicks on and track it.

I found out a couple of interesting things about our Vtec system.

I always thought it kicked on at a set point. Wrong. When in closed loop(half throttle or more), it kicks on at about 5850rpm +/-100rpm.

In open loop(no throttle to half throttle) vtec consistently kicked on at 6500rpm exactly.

Im guessing its due to fuel economy and emissions, but its something I never knew.

[fatality122887]

that's pretty much what the hondata reflash dose on the K20 only at 4.5k and at 5.8k what yr do you have?

[chazdawg35]

Originally Posted by D1sclaimer

On my way home from work, I was experimenting with how Vtec works by using my AFC Neo(newer VAFC). I was using the Vtec monitor on it to show when it kicks on and track it.

I found out a couple of interesting things about our Vtec system.

I always thought it kicked on at a set point. Wrong. When in closed loop(half throttle or more), it kicks on at about 5850rpm +/-100rpm.

In open loop(no throttle to half throttle) vtec consistently kicked on at 6500rpm exactly.

Im guessing its due to fuel economy and emissions, but its something I never knew.

Hey Dude I have a NEO hooked up to my AP1 and can't seem to get the hang of it. Any settings that you know might help me I would appreciate it. I was told that I have to DYNO it to set it right so now I'm running positive throttle and factory settings(no control). Also how do you monitor the V-TEC?

[D1sclaimer]

Originally Posted by fatality122887

that's pretty much what the hondata reflash dose on the K20 only at 4.5k and at 5.8k what yr do you have?

MY 2000 with year 2000 ecu.

[D1sclaimer]

Originally Posted by chazdawg35

Hey Dude I have a NEO hooked up to my AP1 and can't seem to get the hang of it. Any settings that you know might help me I would appreciate it. I was told that I have to DYNO it to set it right so now I'm running positive throttle and factory settings(no control). Also how do you monitor the V-TEC?

For Air/Fuel corrections, keep it at no corrections cause you don't want to risk running lean until you get tuned. You can set vtec to 5500krpm and won't lose or gain any whp, but you do get vtec about 300rpm before its set to kick in.

To monitor vtec, when choosing a display type, choose digital, scroll down to vtec monitor and click on it. Give it a good run to at least 7k and it'll tell when the ecu wanted vtec to kick in and when the NEO had it kick in at. Interesting tool to use.

EDIT: I recall you were looking at getting nitrous? I'd recommend turning off all air/fuel corrections whenever you spray. Changing out jets is a way better way of tuning nitrous as it is always the same(jet sizes don't change unless you change them). The Neo isn't always right on and could make you run lean if your bottle pressure isn't 900-1000psi. Just a thought.

[chazdawg35]

Thanxs Dude I'll play with it today. I was thinking nitro but I don't want to screw anything up.

[chazdawg35]

Hey dude just got home and you were right V-TEC kicks in @ 6500. Now if I went on the freeway about 75 in 3rd the V-TEC was in the 8000 range also do you know about the LO-HI and HI-LO cam settings?

[D1sclaimer]

LO-Hi is what vtec is set to kick in when accelerating. going from low to high rpms.
HI-LO is what vtec is set to turn off when decelerating. going from high to low rpms.