DAYTA

For all you CT S/C owners, how does the fact that you hit VTEC @ 3k RPM affect daily driving?

I love the fact that the CT S/C allows our cars to hit peak torque @ 3k RPM, giving a HUGE powerband between 3k-7k (something I think few people fail to realize). However, as a daily driver, I tend to cruise most of the time between 2.5k-4k RPMs. This makes me concerned that constantly going back and forth between the low and high cams, as well as in and out of boost, will create unnecessary wear on both the engine and the S/C. Am I crazy, or is this actually a possibility?

JTso

iTrader: (2)

Is the vtec switching based on rpm only or is it also engine load as well? I find it hard to believe if it's rpm only.

DAYTA

Interesting point. So it could be that VTEC is engaged only on harder acceleration/WOT. It's hard for non-FI owners to say since even with Hondata, 4850 RPM would be considered a higher engine load. However, 3k RPM is considerably less, so I don't know if that would qualify.

Can any S/C owners chime in on this? Does VTEC always engage once you hit 3k RPM, or is it only under hard acceleration?

JTso

iTrader: (2)

There are a couple of ways to find out. 1. connect a meter or a LED to the vtec solenoid and monitor the change of voltage state at the vtec point during normal driving. Optionally, hook up a vacuum/boost gauge(you should have one already if you are boosting) and monitor the load when vtec switches over. 2. Call Hondata and verify.

TinkySD

I remember them definitely saying the switchover was a vtec "window." Meaning botha combination of rpm and throttle input to decide whether to switch to the high cam or not. What the paramaters are, though, I have no idea.....

Excelerate

iTrader: (1)

VTEC engages based on many different parameters. Even VTEC controllers don't engage VTEC based solely on RPM. For instance on my 99 Accord 2.3T I have the Greddy E-Manage Ultimate installed. There is a window with an x and y axis that has RPM and Throttle Percentage (IIRC). VTEC will engage at 3k RPM only if I have a 100% throttle. It will engage at 3500 RPM if I have 75% or 4000 RPM if I have 50% and so on. Hondata would not have VTEC engage at such a low RPM if it were a problem. At 3K and full throttle there is enough oil pressure to allow VTEC to engage. I am sure Hondata will not have the high and low cam lobes switching based only on RPM.

Tsx536

Yep, it is definitely a Vtec window. It is based on the RPM and MAP (Manifold Air Pressure) reading I believe. I can rev all the way to 5K under light throttle without Vtec kicking in.