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Brenetics
06-24-2002, 09:32 AM
I'm still in the "Break-in" period of my Si,but I was wondering if any of you feel feel VTEC once you hit higher RPMs. And if so, at what RPM

Thanks,
Breon

Mulder
06-24-2002, 10:20 AM
Sorry to say you won't feel the vtec "hit". This version of the K20 has no high lift, long duration, third cam lobe. When Honda refers to this motor as vtec it is refering to the fact it uses only one intake valve until vtec threshold is reached. At that time it used both intake valves, and I believe that threshold to be around 2200 rpm.

On a positive note: Someone here did the I/H/E, and has 157 hp at the wheels... impressive.

xlr8
06-24-2002, 03:20 PM
once you put an aem cold air on you can hear the vtec crossover. its between 5000-5500

Brenetics
06-24-2002, 04:53 PM
do you feel anything though?

02TafWhtSi
06-24-2002, 05:00 PM
its very slight - almost non-existant. The engine definitely creates a higher "pitch" after 4000 RPM but there's no kick in the pants boost in power like the B16 and B18 had - sorry, I guess. This engine is much quieter and more luxurious feeling (smoother, less angry) but still makes really useable power.

xlr8
06-24-2002, 06:54 PM
Originally posted by 02TafWhtSi
its very slight - almost non-existant. The engine definitely creates a higher "pitch" after 4000 RPM but there's no kick in the pants boost in power like the B16 and B18 had - sorry, I guess. This engine is much quieter and more luxurious feeling (smoother, less angry) but still makes really useable power.
i have to disagree i think you can feel the difference with a cold air in stock form you cant even hear a difference though

ApexinSi
06-24-2002, 08:27 PM
I thought the new i-vtec had the vtec on all the time....just spanding out the power band, thats how the torque delivery is so smooth and powerfull.

I beat my friends acura up a hill easily, but on a level strait away he would take me.

iR-VTEC2
06-25-2002, 02:44 PM
thats what I thought too. Constantly variable. Someone please find an article cuz i cant find shiyit!!#!(#

Mulder
06-25-2002, 05:21 PM
Originally posted by xlr8
once you put an aem cold air on you can hear the vtec crossover. its between 5000-5500

What you're hearing is not what you think.

The RXS type S has the K20A2 motor which operates the way you expect vtec to work. It has a third higher lift, longer duration camshaft lobe which engages at about 5800 rpm... hence the vtec "hit". The Si motor is a variant of the K20A3, which has no third camshaft lobe. You will not experience the change over to a "race profile" camshaft because there is none. The Si i-vtec motor is Honda's fuel efficient and low emissions version. It uses the vtec on the intake valves only, and is used only to open the second set of valves at about 2200 rpm.

The "i" in vtec refers to Variable Timing Control. It changes the timing of the intake cam which results in excellent torque plus other benefits.

... So my Si doesn't have the K20A2 motor, does it bother me, nope. It's currently the highest output motor Honda offers for the Civic and it responds well to aftermarket goodies ;)

I got most of this info from Honda Tuning Magazine.

iR-VTEC2
06-25-2002, 05:32 PM
I have that same mag. doesnt it say that it will NOT take to mods that great? I do believe it does. But they of course, are wrong. :D

Mulder
06-25-2002, 06:22 PM
Originally posted by iR-VTEC2
I have that same mag. doesnt it say that it will NOT take to mods that great? I do believe it does. But they of course, are wrong. :D

Yah, what the hell do they know anyways :p

xlr8
06-25-2002, 06:26 PM
im hearing alot of people saying that the vtec crossover is at 2200. this makes me wonder why my car sounds just like a b16a above 5500, but below its quite, hmmm. sounds like there was a typo in some mag. maybe they ment 5200

ApexinSi
06-25-2002, 06:48 PM
Umm......the "i" in i-vtec stands for INTELLIGENT......to clarify that.... Intelligent meaning it's on all the time, I'm almost positive about this.....thats the problem with the 99-00 Si's, the v-tec had to kick in or you had to get a vtec controller to engage it at lower rpms. Honda however made the new Si to have the vtec to always be on just at different power bands, thats how there is so much more torque at lower rpms, unlike previous vtec.

xlr8
06-25-2002, 06:52 PM
Originally posted by ApexinSi
Umm......the "i" in i-vtec stands for INTELLIGENT......to clarify that.... Intelligent meaning it's on all the time, I'm almost positive about this.....thats the problem with the 99-00 Si's, the v-tec had to kick in or you had to get a vtec controller to engage it at lower rpms. Honda however made the new Si to have the vtec to always be on just at different power bands, thats how there is so much more torque at lower rpms, unlike previous vtec.
as far as i uderstand an intellegent engine has an ecu that learns your driving style and changes the timing and fuel management accordingly, just like the wrx.

ApexinSi
06-25-2002, 06:55 PM
Originally posted by xlr8

as far as i uderstand an intellegent engine has an ecu that learns your driving style and changes the timing and fuel management accordingly, just like the wrx.

Well, from what I have read from the many honda articles and tech specs....you just said the same thing I did. Intelligent engine, put vtec on all the time, along with your timing/fuel management.....there is no learning....this ain't a BMW or Porsche.. ...

Someone gonna find some info on this?.....

xlr8
06-25-2002, 06:58 PM
how is it "intelligent" if the vtec is always working. wouldnt that be just like setting a vtec contoller at 2200. im not real sure that sounds intellegent, but i dont want to argue a point im not sure about

ApexinSi
06-25-2002, 07:01 PM
edited out

xlr8
06-25-2002, 07:04 PM
Originally posted by ApexinSi
good then be quit and stop arguing about something you have no damn clue about...a HONDA cannot learn your driving style, are you on crack?.......this ain't a $40k+ car...maybe an S2000, but no Si...
sorry ill ask at king motorsports tomorrow. you dont have to buy a $40000 car to have a learning ecu. the wrx can gain 10+hp at the wheel sfrom someone driving hard. just cause i disagree doesnt me you have to be an asshole

ApexinSi
06-25-2002, 07:09 PM
edited out

ApexinSi
06-25-2002, 07:15 PM
i gave up man, u win. :( ...sorry bout that....we are on the same side.

But i'd like to look more into this....that article i read that has me beliving myself so much was at

http://www.vtec.net/

It had a detailed look at the new si and the i-vtec motor...just gotta find it.

xlr8
06-25-2002, 07:20 PM
i dont mean to be an ass, but i wasnt beeing rude, just trying to figure out this crap about the ivtec like everyone else. if i am wrong then i am sorry for arguing, i havent read this article, and havent had anyone realy say this is what ivtec is and does exactly. since with my aem my car sounds like my friends 2000 si that leads me to believe that there may have been a typo in the magazine. i dont mean to cause a war over something that in a month or two will be common knowlage. as i said i will stop at king tomorrow and ask scott to explain it to me

02TafWhtSi
06-25-2002, 07:24 PM
c'mon gentlemen - we are all on the same page here. Lets try to spread our wealth of information w/out degrading those who may not know as much. We are here to help and give advice not start silly arguments over nothing. :)

xlr8
06-25-2002, 07:28 PM
yeah i have no hard feelings. i hope ApexinSi doesnt i wasnt trying to pick a fight. we will all figure out whats going on together and put our differences behind us

xlr8
06-26-2002, 03:45 PM
well i found out whats up with our ivtec. we were both wrong. it is constantly addapting, not learning. it has no set range where the vtec engages. it depends on a long list of variables, such as throttle position, manifold pressure, and a whole list of things. in scotts words "a simple answer to a complicated question, is it addapts to the conditions its in"

Mulder
06-26-2002, 11:16 PM
I copied this from Honda's own website. I hope it helps.

i-VTEC System
The latest version of Honda's acclaimed valve-control technology, the "intelligent" i-VTEC system combines Variable Timing Control (VTC)--which continually adjusts intake-camshaft phase--with Variable Valve Timing and Lift Electronic Control (VTEC), which changes valve lift, timing, and duration. The result is 160-horsepower at 6500 rpm, 132 lbs-ft of torque at 5000 rpm (a 20 percent torque increase over the previous Civic Si), and exceptional operating efficiency.

VTEC (Variable Timing and Lift Electronic Control)
The Si's VTEC system uses two roller arms per pair of intake valves. During low-rpm operation, intake air is drawn almost exclusively through the primary intake valve, thereby creating a very strong swirl effect to maximize combustion. At higher rpm, the secondary rocker arm engages the primary roller, opening both intake valves for the same lift and duration, substantially increasing airflow into the cylinder and boosting performance.

VTC (Variable Timing Control)
The i-VTEC system adds a new camshaft VTC (Variable Timing Control) system to VTEC for continuously variable camshaft phasing across the engine's entire power band. As engine rpm builds, a VTC actuator--controlled by an engine-control union that monitors cam position, ignition timing, and throttle position--advances or retards the intake cam throughout the 50-degree timing range, optimizing engine output and reducing emissions.


Also, the April/May issue of Honda Tuning Magazine has a great article on the new K series engines.

NetDragon
06-27-2002, 10:26 AM
I am no expert on cars. I know that VTEC stands for Variable Valve Timing and Lift Electronic Control. True my car does hot have a hit like my house mates 2000 Celica GTS (180hp), but I do notice a lot more power after around 4500 RPM's. And after 5300 there is more. When I am getting on the freeway I shift at 6500 if I need to get up to speed quickly and as I am sure you other Si owners know. It has nooooo problem reaching 65MPH in 3rd or 4th gear. Wheeeeeeee!

02TafWhtSi
06-27-2002, 03:29 PM
Originally posted by NetDragon
It has nooooo problem reaching 65MPH in 3rd or 4th gear. Wheeeeeeee!

Was that you or the car?:)

NetDragon
06-28-2002, 12:17 PM
Me saying Wheeeeeee! The car is easiely getting onto the freeway. :cool:

02CivicSI-VTEC
07-02-2002, 03:18 AM
well I usally feel a big up on my car at 5500..i think the vtech kicked in at that point...but not really sure... But Y dose the rpm have to go up to fast???? well my friend have a 98 integ GS with DC header and intake..... and yeah i smoked him with mystockie eheh =) and on the freeway every time i downshifted to 4th gear he cant even catch up....and i was pulling away pretty fast... so far i smoked elicese GS with i/h/e, accord 98 coupe,nad a 97...
which Intak is better for the SI AEM, or Injen??? how much HP dose both give out