How so? VTEC engages based upon throttle position, engine temp, RPM and oil pressure. It's been my understanding that if all of those requirements aren't met, VTEC will not engage. It's not purely RPM-based.
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Given the way it was written, it is not entirely correct. If your load requirment is reached at that RPM, it can go into VTEC at that RPM and still technically be "partial throttle".

 

My point is still the same. Sorry I didn't define the exact load requirements for VTEC to engage. The OP understood what I was saying regardless

 

Look for any of a number of threads from gernby on utilizing the flashpro to do this.

My engagement is at 4100 and will only engage before 6000 if I am >75% throttle (TPS position)

SO in your example OP, I cruise on the highway at 80 but no VTEC as the TPS shows less than required to engage.

The big win in lowering the enagement is a flatter TQ curve and no real HP improvement so you end up gaining more usable power throughout. That said, you only net the improvement if you open up the restriction at the catalytic converter.

There is a thread on the gernpipe that has a lot of this information.

 

OP said the car is an 04.

options for tuning

-Kpro
-Emanage ultimate

or the more expensive

haltech
AEM
etc

Also a good place to check is the Engine and Tuning and NA Setup forum.

im not sure if the other systems do it like the Flash pro since i have an 06. My Vtec engages at 3800 at WOT, and will engage later depending on throttle position and percentage%. Meaning i can be above 3800 RPMS but if i dont exceed a certain amount of throttle input vtec will not engage.

Also keep in mind getting Vtec to engage that low is not possible or beneficial without a HFC or test pipe. Check out Gernby's thread. The stock cat will not let you.

EDIT**

i know its hard to compare but look at my signature link for my car prep. i have a dyno graph there of my car. the torque curve is what counts. you wont gain much HP . i gained 3hp lol.

 

Well my S2000, SI, and GSR all have engaged vtec with only part throttle. Just because you cant hear it doesnt mean it doesnt cross over.. and I def hear mine with my intake/exhaust setups

 

Kpro is more expensive then AEM

 

Most of this has already been posted, but I'll add my own points since this topic is near & dear to me:

The car will not stay on the high cam as soon as your rpm rises above the new/lower vtec engagement point (unless it's tuned incorrectly). Engagement is dependent on load so it will only go to the high cam if you get on the gas.

With the stock catalytic converter in place you can drop the engagement to about 5200rpm. Lower than that will yield a dip in power, which leads me to the next point...

With a test pipe or high-flow cat, you can drop engagement down to 3800rpm or possibly a bit lower. Mine's set at 3600. Completely transforms the way the car drives in the mid-range. You'll gain about 15-20 ft-lbs of torque across the 4000-6000rpm range. It makes the car much more drivable in regular, "real life" conditions on the street.

Because of the necessity to get a test pipe or high-flow catalytic converter in order to drop the vtec engagement below 5200rpm, and because those parts are dirt cheap (a test pipe is only $80-90), I very strongly recommend getting one at the same time you pursue the lower vtec engagement.

Once you decide which tuning solution you want to use to lower vtec engagement, you should find a reputable tuner who can tune the car for you. Without a custom tune you risk damaging your engine and it won't run very well, making the entire venture a waste.

Gas mileage is not affected in any way that would be noticeable. If anything, getting a custom tune (which you should do if you're dropping vtec engagement) may yield a slight increase in gas mileage since the car will be better tuned for your specific engine instead of running Honda's canned tune.




I see you're in Indianapolis. I'm local. If you want, perhaps we could meet and I can just show you first-hand what the car feels like with a custom tune and lowered vtec engagement. I'll send you a PM.

 

Check out this article as it has a dyno comparison with the KPro installed with a lower VTEC engagement point:
http://www.motoiq.com/MagazineArticl...ter-power.aspx

 

[quote name='Syn' timestamp='1396929615' post='23102324']

With a test pipe or high-flow cat, you can drop engagement down to 3800rpm or possibly a bit lower. Mine's set at 3600. Completely transforms the way the car drives in the mid-range. You'll gain about 15-20 ft-lbs of torque across the 4000-6000rpm range. It makes the car much more drivable in regular, "real life" conditions on the street.

Because of the necessity to get a test pipe or high-flow catalytic converter in order to drop the vtec engagement below 5200rpm,

Once you decide which tuning solution you want to use to lower vtec engagement, you should find a reputable tuner who can tune the car for you. Without a custom tune you risk damaging your engine and it won't run very well, making the entire venture a waste.

getting a custom tune (which you should do if you're dropping vtec engagement) may yield a slight increase in gas mileage since the car will be better tuned for your specific engine instead of running Honda's canned tune. (quote)

1. As a guest, I don't think I get email; I don't see where to "click" on it.
2. I really appreciate your offer; I've wanted to drive someone's AP2 with gears, but noone anywhere near has stepped up to offer, but based on what I've read on a couple of sites, I'm not going to persue the lowering of Vtec or I'd love to "sample." It seems like it a whole other level than what someone driving their car back and forth to work would mess with. Stock to me means low/no mainentance, and having to get a special "tune" would require follow ups to keep it in tune.
3. Due to having to get a "tune" and a test pipe/high flow catalytic converter for a custom tune, I'm not going to pursue it.
4. I'm a stock kind of boring guy, and if I would have to change to stock format much, I wouldn't mess with it.
5. In my ignorance, I though it might be a simple "chip" swap, an adjustment of existing settings, or the like.
6. Again, thanks for your kind offer.
7. I have been to the "cars and coffee" at 465/96th area!

 

No problem; I understand where you're coming from. For what it's worth, the car only needs to get custom tuned once and then you can completely forget about it. No ongoing maintenance needed.

Now, the tuning process itself can take several iterations over the course of multiple days/weeks, but get past that and you are golden. I have had two separate custom tunes from two separate tuners, one for a bit over a year and the current one from user Gernby here on S2KI for about 8 months. Never needed a re-tune on either one, and the car has been rock-solid reliable. It's all about finding the right tuner.