Vtech

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what does a vtech engine have that a regular engine have. in general what does the integra gs-r have over the integra ls (both 95) and what do i need to buy to make my ls vtech...cost?

posted by  Crazyjim

please... its vtec


and
you know what honda vtec is right? variable valve timeing and lift. thats what a vtec engine has that a regular engine doesnt...

i tired to answer the question the best i could, but i didnt really understand the question

posted by  mazda6man

how much is it gonna cost me to get mine vtec and what do i need

posted by  Crazyjim

You need a new engine that's VTEC. It's not going to be easy for anyone short of a mechanical prodigee to change valve timing, especially when they have to make it be able to go at un-uniform times, or at least I wouldn't think it'd be any kinds of easy...

posted by  Patrick

there are sites all around the net that say how to do lsvtec swaps... id say go with it... i think its cheaper than going with gsr... the ls is a stronger block i think... not sure tho

posted by  mazda6man

I test drove a 2001 prelude vtech, and I didn't find it that impressive. If you like a little bit of power at like 7000-8000 rpm's then go for it. And that's supposed to be 200hp, the older vtechs put out even less. It had no more power during regular operation than my mom's 04 corolla. It's just that you don't feel any g forces until the rpm's get way the heck up there, and I don't think it's good for any engine to be revving that high regularly.

posted by  DaytonaTurbo

i thought you could just add a vtec head.... im prolly wrong, but some 1 was talkin bout that,

posted by  h22youngin

it takes a little more than just throwing on the head... you have to worry about the ecu, and wiring, and oil lines (vtec uses oil pressure)

posted by  mazda6man

oh, plus others im sure

posted by  mazda6man

Yeah, just a little more.

posted by  DodgeRida67

or you can buy a vtec sticker and stick it on your ls.

posted by  Ki2AY

Ok, a little lesson in VTEC, and why it's important (and why it's impressive) is in order.

To start with, you need to know a bit about how a typical 4 stroke internal combustion engine works, so you know what a cam is, and what the valves do. If you don't know, check out howstuffworks.com, then come back.

The camshaft(s) open and close the valves in an engine, based on their lobe shape (teh lobe is kind of round, but looks a bit like an egg if viewed from teh side) much of it's diameter it's a circle, but for a bit it gets taller, which opens the valve. How tall it gets, and how long it stays there is a large part of what determines how much power the engine make and where that power is made. A typical stock engine had a medium amount of valve lift, and a medium amount of valve opening duration, very little overlap between the intake and exhaust valves being open, and a specific point in the combustion process the valves open AT.

A performance engine might have more lift, a bit more duration, and a bit more overlap, as well as a different RATE of lift. Where you want the power made (and remember, that's determined by torque and rpms) determines the exact shape and position of those lobes on the camshaft.

Too much lift and duration for a particular engine combination, and you might get goot high end power, but be unable to even RUN at low rpms. This is fine for a pure race car, especially a darg car, but not too good for a street car. On the other hand, too mild a lobe profile and you get great around town driveability and low end power, but it runs out of breath pretty quick, and won't rev very far. Great for a street engine but pretty sucky for a race or performance engine.

In the past, REGARDLESS of type of car (be it a BMW 2002 Ti, an air cooled VW, a small block V8 Mustang, or a big block Chevy) you had to balance your specific needs and engine components to determine the optimum cam shape. If you wanted a mostly race car, you compromised towards upper rpm power, but lost street driveability. If you wanted arond town grunt, you wouldn't rev very far. It was always, ALWAYS a compromise. Larger engines less so, as you could still make enough low rpm power to compensate purely from displacement, but for the average sport sedan and traditional sports car with a small engine, nothing dual purpose was EVER a perfect match. And it is a serious pain to install a street cam grind to drive around, then install a race cam on teh weekends to go racing. And you couldn't do it on the fly when you simply wanted a bit of fun. If you put a race cam with a non race intake manifold and carb, you were screwed. Same if you left a street cam in with a race intake and carb setup (like, say, a tunnel ram on an old Chevelle)

Early on, engine builders learned that you could take a slightly tuned cam and adjust the timing a bit advanced to make a bit more power. It wasn't much, but it was easier than swapping cams. Alfa and Porsche put a system in their cars that adjusted teh cams slightly based on rpm to advance it a bit for more power when needed. it wasn't much, again, but it WAS automatic. Soon you could buy kits for it for other small cars. But most engine builders simply picked the best compromise for the intended use, and left it at that.

But then, after a number of years, Honda came along with an absolutely INGENIOUS invention: VTEC. While it stands for Variable Timing and Electronic Control, it was MUCH more. Honda put two separate lobe shapes on each cam, and then mechanically switched between them on the fly at a certain rpm. Not only was the timing of the cam lobe in relation tothe crank changed (by having it operate at a slightly different degree on the camshaft itself), with the change in lobe cam a change in lift, duration, and overlap!

What this meant was that for the first time, you were esentially driving around on a stock street cam around town, but when you wanted to go for it, essentially a mechanic automatically installed a high rpm race cam while you were driving! And installed the stocker back in it when you slowed down. Unhead of! And it took nearly 10 years for anyone to come close to matching it. Variable valve timing is NOT the same! VANOS, Double VANOS, all those are NOT the same. VVTi-L is the very nearly the only one, and it arrived nearly 10 years after VTEC.

With one shot, Honda reinvented the sport sedan and sports car engine.

While the upper rpm cam was no different or no more powerful than any race cam had ever been in an engine, the important thing was that unlike a race cam engine, the Honda system gave back lost low end power and driveability.

ALL small race and performance engines revved good, and made power up high. And still do. ONLY Honda VTEC engies did so while retaining smooth daily driveability when NOT "on the cam." People who say VTEC cars have no low end are kidding themselves, or simply ignorant of how performance engines have always been. The same engine without VTEC would not only haev LESS low end, but very likely couldn't idle at all (or would idle at 2000+ rpm!) and would be very hard top get off the line without either stalling or spinning the tires from dumping the clutch at higher rpms.

VTEC allowed economy cars to economical ability without losing performance capability. VTEC allowed sports cars to have performance engines without losing daily driveability. No one else had done it, and everyone wants it now.

Hell, those of us that used to build fast V8 cars in the '60s and '70s would have LOVED the ability to have our performance cams and daily driveability at the same time! If I could have in a small block Chevy the higher rpm power of a Comp Cams 260/555 (3000-7000 rpm) and the daily driveability of a Comp Cams 224/470 (1500-5800 rpm) in the same engine at the same time, it would have been pure magic!

As for ADDING VTEC to a non VTEC engine... As was mentioned the system is both mechanical and electronic. Besides the cam lobe switchover (which requires a special head for the mechanical bits), the electronics often control dual passage intake manifolds (long runners when on the upper rpm lobes, shorter runners for the low rpm lobes) as well as other changes in the engine arrangement. You can replace a non-VTEC engine with a VTEC one, but you can't MAKE a non-VTEC engine into a VTEC one without a pile of money and a machine shop...

OTOH, if all you want is the ultimate performance, you can still put a race cam and manifold/induction/exhaust system in there with higher compression pistons. You'll get the power and rpms of the upper rpm lobe in a VTEC engine. You'll just lose daily driveability like modded traditional sports cars and sport sedans have suffered with forever.

posted by  ChrisV

an LS/VTEC engine is precisely that, a non-vtec bottom end (B18a1 from DA integra or B18b1 from DC integra) with any VTEC head from the same series motors. any b series vtec head (B16, GSR, ITR) can be used on any B series bottom end. the ONLY difference in the bottom ends is the LS bottom end is only good to rev to 7k RPM, not 8k like the GSR. if you were to use an LS bottom end (b18b1) with a GSR head, you would essentially have a GSR that can only rev to 7k, not 8k. that would be the only difference, but since hondas make lots of REALLY high end power, you wouldnt make GSR amounts of power from an LS/VTEC but if you dont rev one past 7k you will be safe and still make considerably more power. also, since the LS bttom end is good to 7,000 the prelude DOHC VTEC ECU is the best to use (P13) since it has the revlimit set at 7,200 so if you were to miss a shift, you wouldnt spin a rod bearing (like i did on my 97 GSR B18C1) you would just hit the revlimiter instead.

posted by  HOOKSH

Should have clarified, I was saying you can't make a non-VTEC non-HONDA engine into one. Using the bottom end from the LS is merely using the same block casting, so of course you can put a VTEC head onto it, as the basic engine was engineered as a VTEC engine, then Honda decontented it (swapped the head out) to be a non-VTEC engine.

posted by  ChrisV

o yess the VTEC, it is ingenius.
If possible, to swap a non VTEC would not be worth the time and $$, the VTEC is a great thing, dont get me wrong, but its a little more HP at higher rpm, is it worth all the effort?

posted by  BuggatiV

A Vtech engine has like 30hp more than the LS motor, but I guess if you plan on long term tuning, then do the swap. Short term, you'd probably get more out of a turbo charger.

posted by  Anbuhero

Sorry to ask this question but does the regular VTEC use 3 rocker arms and valves? Is the new i-vtec use 2 or 3 rocker arms and cam lobs?

posted by  CarEXPERT

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