Why does the VTEC engage so late?

[chimchim]

On my 97 EX stock D16Y8, I wanted to know once an forall exactly when VTEC engages because you can't hear/feel it on this SOHC. So I put in a VTEC light (inconspicuously though).

VTEC comes in like 5500-5700 RPM... when redline is like 6500.

Why so late? There's less than 1000 RPM where the higher profile is active. That doesn't seem that useful. Why did the Honda engineer choose that point? How about something like 4.5k or something... or at least 5k. As it is, unless you're racing your car, VTEC will almost never be used. And I thought Honda was designing for the daily driver.

Granted the power curve as it is is fairly smooth, but would have wanted more aggressive VTEC at > 4.5k.

Anyone have an idea why it wasn't designed to engage earlier?

 

[$lick Rick]

my vtec on my d16z6 engages at 4900 rpm and my redline is 7200. i can hear my vtec and even feel it in 2nd gear.

 

[LatinEM2]

mine engages at 5500 rpms till redline (8000 rpm)

 

[$lick Rick]

you can always get a vafcII and a blank ecu. then you could program it to do anything you want

 

[Noeladams]

I can hear mine some with my d16y8 but I would like to find out how to lower it to about 4.5 or something.

 

[anfrey]

the points for vtec engagement (acceleration) and disengagement (deceleration) can be alterered with a vafc, with the greddy profec, and thru several other options

 

[$lick Rick]

i'm going to get a bigger cam soon, currently i'm more than happy with my engagement points but as anfrey said it can be dropped. there are even less expensive vtec controllers on the market, google it up

 

[anfrey]

i believe the fields controller might be cheaper than the apexi

 

[2kstreetcivic]

ya...kinda dumb it ingages so late..but just switch it..not really worth it in my opinion if you dont have some engine mods..but I would love have mine kick in at 4 grand..that woud be sweet...you would still be in vtec when you shifted..

 

[anfrey]

from what i recall, vtec disengages at 4800

 

[zville00SI]

The vtec on sohc d series engines are called the vtec-e, or the economy vtec. This vtec is designed for the economy car. The reason it kicks in so late is so that it is only used when needed. You don't want an economy car with vtec kicking in at 3 grand rpm's. The vtec on the b16's etc... are vtec dohc, which is the more hard hitting vtec. This vtec is less designed for economy, rather it is designed for performance. I believe there are 4 different kinds of vtec, and I just explained two of them. I hope this helps.

 

[Vallejo_raider]

then how about for the 7thgens? there sohc vtec? something with the vtec-e? also how about on those k series engines, whats the i-vtec? intelligent-vtec?

 

[anfrey]

The vtec on sohc d series engines are called the vtec-e, or the economy vtec. This vtec is designed for the economy car. The reason it kicks in so late is so that it is only used when needed. You don't want an economy car with vtec kicking in at 3 grand rpm's. The vtec on the b16's etc... are vtec dohc, which is the more hard hitting vtec. This vtec is less designed for economy, rather it is designed for performance. I believe there are 4 different kinds of vtec, and I just explained two of them. I hope this helps.

that is not true for all d16s. i have what is known as VTEC-II according to honda. at least for 6gens, VTEC-E was only available on the HX trim.

 

[[civic]]

VTEC-E was only available on the HX trim.

yup yup, that is true..

 

[anfrey]

i'm speaking USDM civics, of course.

 

[anfrey]

btw, what does "???????????????" mean? and why does it say kia rio! down there? roflmao

 

[[civic]]

btw, what does "???????????????" mean? and why does it say kia rio! down there? roflmao

I was just commenting on your comment about the HX.

kia rio? im just trying to represent for the loser fellow with the kia turbo. haha

 

[anfrey]

lol... i guess it didn't come out... i didn't mean to put a bunch of question marks there. i was curious about the japanese text

 

[chimchim]

My D16Y8 is not a VTEC-e. VTEC-e (as said earlier) was only on the HX in the 6th generation, and it engaged much sooner because it was going from the essentially single valve intake to 2.

I know I can mod the point with a controller, but I want to know why Honda chose to put it in a near useless point. Now, if the cam was really agressive, then I understand why it would wait until 5500. But it's not (looking at the power curve), so I don't get it.

Anyone know?

 

[[civic]]

lol... i guess it didn't come out... i didn't mean to put a bunch of question marks there. i was curious about the japanese text

It means eat sushi...no i dont know what it means either.