VTEC does it really do anything?

Well the other night coming from a friends house a 2000 accord VTEC reved up at me.I smoked him.I smoked him at every light.There was a total of 3 so u cant say it was luck.But damn VTEC is so fucking loud.Anyways i could hear his VTEC kicking in but it sure didnt do anything for him.So the question is does VTEC work or does it just make your car sound like a fuckin beast?

i think some uk dude has the best answer to that. "it's like a very small turbo that for some reason take 5500 rpms to boost... ahh i can't remember the rest of it. so yes it does work. it acually does what it suppose to very well.

I raced a v6 accord a few times. And I destroyed them everytime....

The autobox in the v6 is pretty slow, so I dont know if the 4 cyl one would be any faster in auto.

All v6 accords were auto til 2001 I think, with the arrival of the new body style. Try racing one of those and then get back to us. hehehe

Funny thing is i got beat by a modded v6 mustang the other week.All that my friend added was an intake and dual exhaust.I used to smoke him.But know he beats me by alot.I guess domestics respond better to mods.

i dont see how these 108hp engines are so quick.:rolleyes:

maybe the accord and mustang werent racing.

Originally posted by 95civicman
i think some uk dude has the best answer to that. "it's like a very small turbo that for some reason take 5500 rpms to boost... ahh i can't remember the rest of it. so yes it does work. it acually does what it suppose to very well.


Well thats wrong. V-tec has nothing to do with force induction so its NOT like turbo:rolleyes:

I know what your talking about....


I think its moppie that has that little convo in his sig...kinda funny.



Regardless of your "kill", vtec isn't always used for one thing. On some engines, it makes for better gas mileage, while on other motors, such as the b16, the cam profile in vtec is much more aggressive. So just because a Honda has vtec, doesn't necessarily mean its fast. Look at the Civic Hx for example, nice car with a great motor, but vtec is used to gain fuel econonmy, not performance.

My bad, it was in Sentata's sig...here it is for your viewing pleasure...

And if not, :thefinger :thefinger :thefinger :thefinger
PUT THE CHEESE IN YOUR BUM!

k3nnis: Can you explain how VTEC feels like when it kicks in? Does it pin you back to the seat a little bit like a turbo?
sejanus: Imagine a incredibly tiny small turbo that for some bizarre reason takes 5500-6000rpm to make boost, and so small that it makes bugger all power, just an increase in noise

The main use of VTEC is to provide good high rpm performance(Secondary Lobe [I think a few VTEC engines had three]) while still having an efficient low end power curve and a smooth idle(Intial Lobe)

VTEC is only good for high performance street cars when it comes to modding.

When you are racing you don't really need to worry about lower rpms or a smooth idle.

Dude your CRX weighs like half of what a freakin Accord does - and you wonder why you smoked him? LMFAO ! :lol:

So let me get this straight.. You beat a car with VTEC? Fuck, I'm an idiot.. VTEC must not be anything at all, but a sound.

Thats it, I'm selling my B16A for an A6, anyone take a straight trade?
What a fool I was all along.

Originally posted by SiZ
So let me get this straight.. You beat a car with VTEC? Fuck, I'm an idiot.. VTEC must not be anything at all, but a sound.
Thats it, I'm selling my B16A for an A6, anyone take a straight trade?
What a fool I was all along.

:biggrin: im with you homie. lol

I personally think vtec does work. I just think it is highly over rated. I got a friend with a 93 Civic Y8 vtec and I can beat him.

i think that the sohc vtec doesnt really do any thing but u can really feel it in a dohc motor.

Dudes, someone that knows how to drive a new 6-speed v6 accord coupe can hit high 14's easy.

And another thing, VTEC is shitty for drag racing. That's why some company called TODA :biggrin: makes this product called VTEC KILLERS (only for racing purposes) because you get power all the way through instead of just at 5500rpm+

VTEC is somewhat highly over-rated when it comes to people telling their stories as to how their "V-TEK kicked in and i beat him by like 5 cars":iceslolan itz just something that helps ur engine preform better in high rpms or if u have a VTEC controller, can have that help early on in the game instead of waiting...i guess u can call it a "performance enhancer":biggrin:

Originally posted by 4g4d_getone
i think that the sohc vtec doesnt really do any thing but u can really feel it in a dohc motor.

I agree, I have a friend w/ a '99 Civic EX with only a muffler and short ram intake and i have beat him even though he has V-TEC (though be it only SOHC). I have also driven his car and once u hit vtec it isn't that noticable....however i do agree about the DOHC V-TEC like in B16's and B18's how it is much more noticable it actually is.

VTEC is obviously gonna do alot more in a DOHC car with a more powerful engine. And if you had a 91 si hatch or whatever...you're car would be alot lighter and have no much less power then the ex's so nothing would suprise me there.

Originally posted by toronto pimp
VTEC is obviously gonna do alot more in a DOHC car with a more powerful engine. And if you had a 91 si hatch or whatever...you're car would be alot lighter and have no much less power then the ex's so nothing would suprise me there.

Well i dont have a 91 si hatch but i do have a 90 Civic EX which of course has the same engine as the SI's of that generation so you were close enough :iceslolan Right now it's being swapped out for a SOHC ZC though and will probably have it back by this Saturday (i can't wait, been almost a month since i've driven my car)

sohc vtec isn't meant to be some high performance 8000rpm monster, it is meant to give the car extra power in situations like highway passing.

The same type of effect is achieved in trucks that use the Miller cycle instead of the standard Otto cycle.

In Europe there is a d15 sohc with three different stages of VTEC that makes 130 hp and gets 54 mpg.

I would love to see that combo of 130 hp and 50+ mpg considering my life as a 16 year old isnt filled with money to spare or rich parents to have pay for everything.

Originally posted by DarkImportGrey
In Europe there is a d15 sohc with three different stages of VTEC that makes 130 hp and gets 54 mpg.

yup the d15b out of 92-95 civic vti's in japan... pretty bad ass lil motor, my friend had one in his crx before he went b20/vtec... there's a shop here in my town that sells them. Japanese Engines Inc. about 650-700 for the whole swap

Hey jNYCe5 Does this shop have a web site or a phone number where they can be reached.

I just bought a 91 Civic Dx 4dr with 266K and I need to do something with this motor.

Thanks,
Mark D

We need Setanta here :icon16:

Got a little bored. Here ya go. Enjoy!


VTEC is an acronym for Variable valve Timing and lift Electronic Control. It is a mechanism for optimizing air/fuel mixture flow through the engine.

An internal combustion engine converts the chemical energy stored in fuel into thermal energy. The increased thermal energy within a cylinder causes the pressure to build. This pressure acts on the pistons and the result is a mechanical force rotating the crankshaft. This mechanical force is measured as crank torque. The ability for the engine to sustain a certain level of crank torque at a certain RPM is measured as Power. Power is the rate at which the engine can do work. This conversion process is not 100% efficient. In fact, only about 30% of the energy stored in the fuel is actually converted into mechanical energy.

Physics says that for a given efficiency level, a higher rate of fuel consumption is needed for the engine to generate power. So it becomes obvious that if you want more power, you need to increase the rate of fuel combustion. One way to achive this goal is to have a bigger engine. A bigger engine with larger cylinders will be able to combust more fuel per rotation than a smaller engine. Another method is to pre-presurize the fuel/air mixture and cram it into an existing engine size. Thus even though the cylinder size stays the same, more fuel is combusted per rotation. This second method is referred to as forced induction.

Honda chose to explore another method: keep the engine size the same, but turn the engine faster to consume more fuel. Here is an analogy: You want to move foam peanuts from one bucket to another with a cup. You can increase the size of your cup, compress/cram as much peanuts as possible into the cup each time, or you can just move the cup faster. All three methods moves more peanuts. Honda uses the last method. And again, more fuel combusted equals more power generated by the engine.

As the engine speed is increased, more air/fuel mixture needs to be "inhaled" and "exhaled" by the engine. Thus to sustain high engine speeds, the intake and exhaust valves needs to open nice and wide. Otherwise you have what is akin to athsma: can't get enough air/fuel due to restrictions.

If high speed operation is all we have to worry about, Honda wouldn't need to implement VTEC. Indeed, race engines that operate mostly at high rpms do not utilize any mechanism like VTEC. But street cars used for daily driving spend most of their time with the engine at low RPMs. Valves that open wide for high RPM operation contributes to rough operation and poor fuel economy at low RPMs. These undesirable traits are directly against Honda's design goals.

The solution that Honda came up with is the VTEC mechanism: open the valves nice and wide at high RPMs, but open them not as much at low RPMs. So now you have a engine with smooth operation at low RPMs, and high power output at high RPMs.

And that is basically what VTEC is. It's nothing magical. The idea has been around for a long time. Honda's VTEC is just a very simple, elegant and efficient implementation that is extremely effective at achiving its design goal. Honda automobiles are the first among modern automobiles to utilize this mechanism in such a large scale of distribution.


Honda first introduced the DOHC VTEC mechanism in the US on the 1990 Acura NSX. But a year earlier in 1989, the Japan Domestic Market got the world's first dose of DOHC VTEC in the 1989-1993 generation of the Honda Integra. The 1989 DA6 Honda Integra RSi/XSi used a 160ps variant of the B16A DOHC VTEC engine. Honda enthusiasts would recongnize the B16A engine since it is currently used in the 1999 and 2000 US-spec Civic Si and Canada-spec Civic SiR. However the B16A used in the current Civics is a second version of the original B16A. The main difference is that the newer US-spec B16A has slightly more power at 160hp.

Okay that's enough history. Lets see how DOHC VTEC works. The figure to the right shows a simplified representation of a intake-valve VTEC mechanism (the exhaust mechanisms work similarly). So for each pair of valves, there are three cam lobes. The two on the outside are low RPM lobes and the one in the middle is the high RPM lobe. The two low RPM lobes actuate the two valve rockers, which in turn pushes the valves open. The high RPM lobe actuates a follower, which is shaped like a valve rocker, but doesn't actuate any valves. The figures show the circular section of the cam lobes touching the valve rockers, and the eliptical section pointing away. Thus the valves are closed in this stage.

During low RPM operations, the two outer cam lobes directly actuates the two valve rockers. These low PRM lobes are optimized for smooth operation and low fuel consumption. The high RPM lobe actuates the follower. But since the follower isn't connected to anything, it doesn't cause anything to happen. This procss is illustrated by the figure to the right.

At high RPMs, oil pressure pushes a metal pin through the valve rockers and the follower, effectively binding the three pieces into one. And since the high RPM lobe pushes out further than the low RPM lobes, the two valve rockers now follow the the profile of the high RPM lobe. The high RPM lobe's profile is designed to open the valves open wider, and for a longer duration of time, thus allowing more fuel/air mixture to enter the cylinder. The improved breathing allows the engine to sustain its torque output as RPM rises, thus resulting in higher power output

That is basically how VTEC works. The picture to the right is a picture of an actual DOHC VTEC engine. Note that there are two cam shafts, one for the intake valves and one for the exhaust valves. For each pair of valves, notice that there are three cam lobes: two cam lobes on the outside, and one cam lobe in the middle.

As I've said before. The VTEC mechanism is nothing spectacular. DOHC VTEC is the most ambitious of all VTEC varieties in terms of specific output (except for the up coming VTEC-i). Yet as you can see, the implementation is elegantly simple. VTEC is Honda's solution to the design goal of improving engine breathing at high RPMs while retaining smooth and economical operation at low RPMs. DOHC VTEC technology is currently used in the 160HP Civic Si, 170HP Integra GS-R, 195HP Integra Type-R, 200HP Prelude base/Type-SH, 240HP S2000 and the venerable 290HP Acura NSX. And these are just the US-spec cars. Saying that VTEC is a successful design is an understatement.

*Edit*
Before all of you flame me for not writing this. I got this off howstufworks.com. ^_^

i wouldnt mind having that engine for the mpg and extra performance

Originally posted by Problem_Si
My bad, it was in Sentata's sig...here it is for your viewing pleasure...



yea that's it. i wasn't sayin it was like a turbo, just sayin that because it was funny.

Umm.... correct me if I'm wrong, but I do believe the i-VTEC engine currently in the Acura RSX (type-S) utilizes the three-lobe system that DarkImportGrey is speaking of.

Of course, that's my opinion, I could be wrong. :biggrin:

-Adam.

the three lobe system in the euro d15 however is not the same system as the RSX type S head...

on the euro d15 that gets 54mpg, one of the cam lobes is almost perfectly round...

I have a B16 in my hatch and you can clearly tell when VTEC kicks in. B16's are nothing without VTEC.

My friend has a 94 Del Sol Si with the D16z6 SOHC VTEC motor, and everytime I drive his car, you can kinda tell when VTEC engadges. Not as loud as my engine when I hit VTEC, but its there, no real boost in power (compared to my B16 at least).

Now I have another friend of mine that owns a 02 Civic Si with the i-VTEC K series 160hp motor. I really dont care for the new i-VTEC motors cuz there is NO power noticeablity when VTEC engadges. He says that his VTEC kicks in at 2000 RPM (the first stage that is). That motor was designed for optimum fuel usage, not really for power. Just think of it this way (I sure as hell do...) i-VTEC = diet VTEC :loser: :iceslolan

well the k20 in the new civic si makes 160hp from 2 liters, while the b16 makes 160 from 1.6L, so the cam profile has to me more aggressive to get that kind of power from a 1.6L, also, the K20 in the civic is pulling a heavier car than yours, so it's not going to feel as quick...

the si also only has ivtec on one set of valves, either the intake or the ehxuast i can't remember, while the b16 has vtec on both intake and exhaust, and the rsx-s also has ivtec on both cams.

All I know is that VTEC is awsome in 1st and 2nd gear, it pushes you back in your seat a bit. After that it's more like a noise, you can't feel anything when you hit VTEC you just hear your engine get louder. At least that's my experience with my B16.

theres a performance shop where i got my car worked on, and the manager has a crx with a frankenstein motor in it. he gave me a ride home in it since they was workin on my car and that fukn motor is mad fast!!!!! hes got a LS block with a B16 head and ecu, not to sure which tranny but his whole car is gutted out, the only thing he has in it is two racing seats and a roll cage. he took out the whole dash board and just left the speedometer, rpm gauge, gas gauge.

if ur thinkin about doing an all motor frankenstein i highly recommend it but it will make a hole in ur pocket!!!!

also the owner of that shop has a crx with a spoon B18c8 i think thats what the code is but its just over the type R motor. i havent had a test drive in that but he only uses it for the track and over here on saturday nights we have street racing so he uses it then also.

The new i-VTEC is optimized for smoothness of power delivery so you can't feel the boost...they did that on purpose.

VTEC isn't magic but it's definately a plus. Basically free low end torque and free high end horsepower, with no penalty to fuel economy.

Originally posted by Marc-OS
All I know is that VTEC is awsome in 1st and 2nd gear, it pushes you back in your seat a bit. After that it's more like a noise, you can't feel anything when you hit VTEC you just hear your engine get louder. At least that's my experience with my B16.

Yeah, in my friends '03 RSX-S with AEM CAI and Tanabe exhaust through the first 2 gears i-VTEC is quite noticable, but in 3rd you can still feel it making a lil more power once it kiks in at about 5700rpm or so. Even if it doesn't make more power the noise sounds badass, lol.

I just dont know why people with si's swap there motors out for the d16z6.I mean its cool if your engine went bad but other than that i dont see the reason for swapping it.Its just a 17 HP difference.

For the price of a D16Z6 its cheaper than a couple of bolt ons for your A6, and you'll never see a 17hp increase for the few hundred dollars that a Z6 costs..

I don't understand why people buy intake, header, exhaust, cam, adjustable cam gears, etc. for an A6 when for the same price you could have just bought a Z6 or a ZC and it would be probably cheaper, and you'd have more HP from the get go.

My cousin's Integra Type R's Vtec rocks like all. Shoot, screw all the other vtec cars. The only true dohc vtec car is the ITR.

The only true dohc vtec car is the ITR.
Wow, and all this time I was thinking that the NSX had "true" vtec, must have been that fake stuff they sell on t.v.

-Derek

My friend has a stock crx si with only an exhaust.He just got a gude cam and an AC camgear and his car dynoed at 127 hp.He only spent 180 for the cam and 100 on the cam gear.Know you mean to tell me that with 280 you can get a z6 installed.plus if you took the d16z6 it prolly would only dyno at like 115 HP.

Originally posted by mellowboy



Well thats wrong. V-tec has nothing to do with force induction so its NOT like turbo:rolleyes:

Oh FFS - it's an analogy. Bloody illiterates :loser: :thefinger

Originally posted by l2ice rocketz
My cousin's Integra Type R's Vtec rocks like all. Shoot, screw all the other vtec cars. The only true dohc vtec car is the ITR.

Hahahahaha - gee whiz - I guess that makes my SiR an "untrue" DOHC VTEC car, along with the VTiR EK4, the CTR, EF8 CRX, NSX, EG Del Sol/CRX, Integra XSi/RSi, S2000 ETC.

Get back under your bridge troll :loser: :loser: :loser: :thefinger :thefinger :thefinger

Talk about ignorant :P

Originally posted by crx hf
My friend has a stock crx si with only an exhaust.He just got a gude cam and an AC camgear and his car dynoed at 127 hp.He only spent 180 for the cam and 100 on the cam gear.Know you mean to tell me that with 280 you can get a z6 installed.plus if you took the d16z6 it prolly would only dyno at like 115 HP.

He gained 35+whp from a SOHC with a cam, exhaust and adjustable cam gear? Sorry, there's NO WAY I'm buying that.

Originally posted by SiZ


He gained 35+whp from a SOHC with a cam, exhaust and adjustable cam gear? Sorry, there's NO WAY I'm buying that.

Prolly had a Sweedish CAI on it - that's good for at least 2 seconds on the 1/4 remember :dogpile:

Wow, too bad I don't have one of those, I could be driving a twelve second car. Maybe I should look into buying TWO cams for my car.. I'd probably gain like 50whp..

:rolleyes:

He got the whole GUDE head package.