matteichenfels

when I bought my car, i never found out what v-tech actually does.

Acura3.0CL

you mean VTEC.....from what i know...heres the lowdown...the Acura CL years 97 - 99 have SOHC VTEC....that single over head cam (mean one cam rod in the engine)...SOHC VTEC is slower than say the Preludes DOHC VTEC (the have dual over head cams)

VTEC is then you whomp on the gas, it kicks in, the rpms fly up and you get thrown back in your seats...its when you lay on the gas, the valves in the engine say open longer.

I donno the whole actual definition of the word but its like valve timing control...so the valves stay open longer allowing more gas into the engine to burn = higher rpms and u go faster...

all and all...its hella nice to have! (hehe) Now i donno how good i explaned this but dont quote me on anything cuz im sure i dont know everything about it...i know someone elce will know alot more than me...this is juat all that i know...

matteichenfels

thanks for the info,( i meant to write VTECH) So that's where that burst of power comes from! So when your engine is somewhat cold and you floor it, then let off the gas, thats what sends you through the windshield?

dustbuster4

It's VTEC; no "H" at the end (Variable valve Timing and lift, Electronic Control).

matteichenfels

i'm retarded, I keep writing the same thing-VTEC-there!

Blacura

VTECH makes phones and electronic stuff

Honda makes VTEC

If you get an intake you'll be able to tell when VTEC engages on your car.

matteichenfels

cool, what do you think the best air intake would be for a 3.0 cl?
short, long, powdercoated?

dustbuster4

Get the AEM CAI (for the '98-'02 Accord V-6)

matteichenfels

does it sound the best?

dustbuster4

To me, they all sound about the same (in terms of brand name).

However, my short ram has more of hummmmm, than my CAI.

lowboy

VTEC (variable valve timing electronic control) it changes the timing of ur car to dump more fuel and air into he motor which in turn makes more horsepower THAT IS WHY U FEEL THE SUDDEN KICK WHEN VTEC KICKS IN

nandowong

If you have read How Car Engines Work, you know about the valves that let air into the engine and let exhaust out of the engine. You also know about the camshaft that controls the valves. The camshaft uses rotating lobes that push against the valves to open and close them. This animation from How Camshafts Work can help you understand how the camshaft opens and closes the valves:




It turns out that there is significant relationship between the way the lobes are ground on the camshaft and the way the engine performs in different rpm (rotations per minute) ranges. To understand why this is the case, imagine that we are running an engine extremely slowly -- at just 10 or 20 rpm, so it takes the piston seconds to complete a cycle. It would be impossible to actually run a normal engine this slowly, but imagine that we could. We would want to grind the camshaft so that, just as the piston starts moving downward in the intake stroke, the intake valve would open. The intake valve would close right as the piston bottoms out. Then the exhaust valve would open right as the piston bottoms out at the end of the combustion stroke and would close as the piston completes the exhaust stroke. That would work great for the engine as long as it ran at this very slow speed.

When you increase the rpm, however, this configuration for the camshaft does not work well. If the engine is running at 4,000 rpm, the valves are opening and closing 2,000 times every minute, or three to four times every second. When the intake valve opens right at the top of the intake stroke, it turns out that the piston has a lot of trouble getting the air moving into the cylinder in the short time available (a fraction of a second). Therefore, at higher rpm ranges you want the intake valve to open prior to the intake stroke -- actually back in the exhaust stroke -- so that by the time the piston starts moving downward in the intake stroke, the valve is open and air moves freely into the cylinder during the entire intake stroke. This is something of a simplification, but you get the idea. For maximum engine performance at low engine speeds, the valves need to open and close differently than they do at higher engine speeds. If you put in a good low-speed camshaft, it hurts the engine's performance at high speeds, and if you put in a good high-speed camshaft it hurts the engine's performance at low speeds (and in extreme cases can make it very hard to start the engine!).

VTEC (which stands for Variable Valve Timing and Lift Electronic Control) is an electronic and mechanical system in some Honda engines that allows the engine to effectively have multiple camshafts. As the engine moves into different rpm ranges, the engine's computer can activate alternate lobes on the camshaft and change the cam's timing. In this way, the engine gets the best features of low-speed and high-speed camshafts in the same engine. Several of the links below go into the actual mechanics of the VTEC system if you are interested.

Several engine manufacturers are experimenting with systems that would allow infinite variability in valve timing. For example, imagine that each valve had a solenoid on it that could open and close the valve under computer control rather than relying on a camshaft. With this type of system, you would get maximum engine performance at every rpm range. Something to look forward to in the future...



From the most imformative website in the web

how stuff works

CL22

Is the CAI better or short ram better?

CLpower

the vtec on the 3.0 motors is very unique, Ross gave a good talk about it a few months ago. Maybe he'll chime in.

rmstoico

sohc and doch vtec's are different. but to make things simple.

vtec is activated by 5 things. engine rpm's, oil pressure, speed of the car, and some other stuff.

i will try to make this simple.

before vtec kicks in your engine runs normal.

after vtec kicks in, a pin is shot through the valve rocker, which connects via the pin to a follower rocker (which normally does nothing during non-vtec operation). this follower rocker connects the valve rockers together jointly, now the follower which is normally inactive and idle is now working with regular valve rockers. underneath the follower rocker is another cam lobe on the cam with a higher profile. since the follower is now active it connects to that lobe now and you have a greater duration on your valves.

the j30's have a 2 stage vtec.... the first stage activates the second pair of exhaust valves. keep in mind, only 2 exhaust valves are working during 0-3700 rpms. first stage is the second pair of exhaust valves opening, stage 2 vtec is the actual occurance popular to everyone as vtec, where the higher profile cam lobes are used.

for all other hondas and acuras, there is only 1 stage, and that is the valve lift stage previously described.

in europe there is a 3 stage motor, the d15.

ivtec is a constant vtec that is always working, still not sure how its done yet though.

***btw, substitute exhaust valves with intake valves, i was not thinking.

matteichenfels

thanks for all the info guys!

KENLUDE97

Now granted this is on the H22 (Prelude engine) but the principal is the same. This opperates both intake and exhaust yours only opperates the intake.



see that middle cam profile? It is "Taller" and "Wider" Higher lift and durration. Now a standard DOHC engine in like this Stratus there is no "middle" profile.


What happens is that when VTEC activates the Valves open further and stay open longer. There fore letting more air&gas enter the Combustion chamber there for making more power.

matteichenfels

I'm learning alot!
I went to a local store-SPEED OF SOUND here in Pittsburgh today, they gave me quotes for CAI's. I know the guys there, so they said the'd give me a deal ... aem=$210, and injen=$180. Which one is better, and IS this a good deal?

ding069

$180 for an injen CAI is a great deal! Take that up. AEM's, you can get for around $180, but dont perform as well as Injen. Injen is more expensive, but you get what you pay for in this case of intakes.
BTW, if you cant feel or hear it, VTEC kicks in at about 3500 RPM's. The noise of VTEC is amplified by the use of an intake.