.

 

now i know why canadians love Honda so much

 

Doesn't every Japanese and European car manufacturer do this by now?

 

YEs. Variable valve timing was pioneered by Alfa Romeo in the 80s if I remember correctly but became a market hit by Honda with Vtec. I remember that excluding the NSX in 1990, the CRX was one of the first mainstream vehicles to get VTEC with two engines in Europe. Both 1.6 liters, in 1991-2 they made 120HP without VTEC and 160HP with VTEC. But since then and up until before iVtec which was marketed in USA only one or two years ago, Honda seemed to be way behind when compared to other manufacturers, like BMW for example. Most manufacturers now use some form of variable valve timing and lift. They execute it differently but the principle is the same.

Many enthusiasts will claim that BMW probably is ahead in this technology for some time now, especially when combined with Valvetronic and other technologies.

 

True. That said, I would have loved to see how a C32A (or maybe a DOHC version of the J32A) w/iVTEC would have fared against the S54 in terms of 'hp/tq vs hp/tq'.

 

Unlike BMW, Honda's Vtec doesn't blow the fuck up after 80k miles.

Every used-car "guide" I've ever seen for a BMW with valve-timing always has "Beware of Vanos problems" all over them.

 

^ True. I have noticed that also but only on certain specific model-years.

 

I've seen it on 5-series that have it from 1989 to the end of the E39 run.

I've seen it on 7-series that have it during the same period (obviouly from sharing engines)

I've seen in on Z3s that have it since inception

I've seen it on 3-series that have it since at least the mid-90s

It's just a problem with the Vanos system in general ... Must be the way in which it works. And to fix it is hella expensive.

I love the late-80s M5 ... I'd never get one because if the Vanos system goes tits up, it's like 11ty gajillion dollars to fix

 

 

Don't the R-series Honda engines have an evolved form of iVTEC?

 

Its like $350 for the vanos unit and install isnt that hard.

Bu yea sucks that they fail.

 

One of the problem with small displacement VTEC or even iVTEC is that it can generate loads of horsepower, but not torque. Torque is crucial to move a heavy car. Torque comes with displacement, or turbocharging. There is no way around it.

 

The K24 in the TSX doesn't do too bad. It's torque curve is relatively flat, and even though it has only 166lb-ft, 90% of that is available at 2000RPM, so it feels very peppy for a 4 banger. And from what I've read on the R18, I hear it's pretty torquey for such a small motor (designed for the Civic of course).

 

But if it has 200+ lb-ft of low-end torque, the car will be flying. Maybe another second faster time from 0 to 60 mph.

The Audi 2.0T generates 207 lb-ft @ 1800 rpm with turbocharging. The K24 can never generate this level of torque without going force-induction, or going from 2.4L to perhaps 3.0L. My point is that torque only comes with engine displacement or force-induction. Not even VTEC or i-VTEC can change this.

 

That's true. I'm not disagreeing. What's wrong with i-VTEC in cars meant to be economical anyway? I think people would freak out if the minimum size engine you could buy was 3.0L and any smaller and you have no choice but to have a turbo.

The vast, VAST majority of people could care less whether their Civic has less torque than their mom's Sentra. All they care about is that the Civic saves them $10 a week in gas.

 

My point is i-VTEC can generate lots of horsepower, but not lots of torque from a small displacement engine. A small displacement i-VTEC engine works well for small cars like Civic and TSX, but for say a 5000 lb AWD RL, it would be dead in the water. It'll need lots and lots of low-end torque to get the heavy car going fast.

The title of this thread is "VTEC engine technology". My comment is that VTEC engine technology works very well in generating horsepower, but still falls short in generating torque.

 

WTF? Jeezus, that's it? The articles made it seem like it was going to be several $Ks just to fix it. : /

 

OK. I will try to shift attention to torque and power which is indirectly relevant to VTEC in this case.

What you're saying is true but not accurate because it's not the whole truth.

The main reason is this:

Torque and Power should not be perceived as different!

That's the only way for all to understand their relationship. Only if they understand that torque and power express the same exact thing. Only they express it differently.

The only difference between torque and power is that torque IS power, only for power to be measured as torque, something must be turning around itself (to put it simply). A shaft in this case.

Torque is power and power is torque.

So if that's true then why dont we all talk power. Horsepower in this case. So it'd be less confusing if in your case you said:

Vtec helps a given engine make lots of peak power but falls short at making serious amounts of power at lower rpm.

It's a lot more comprehensive that way.

The main problem is that people have associated torque with low rpm and HP with high rpm. So when they talk about high rpm, they talk HP, and when they talk low rpm, they express it as torque. The reason for the above is because when you measure power in HP, it peaks at high rpm in gas engines. Always. When you measure power in torque units, it peaks lower in the powerband.

That's confusing though. Think of this:

Torque is always there!

Meaning, just because you look at INCOMPLETE dyno graphs and you see the torque curve disappear many times after 5K rpm, that does not mean that the engine does not produce torque until its redline. If there is power, there is torque, because they are the same thing. They just dont wonna show how little torque their engine makes at high rpm because most of the time, it's miniscule. Same with HP at very, very low rpm. Sometimes both curves start at 2 or 3 thousand rpm. It does not mean that the engine does not make power at 600 rpm where it idles. It also makes torque there of course.

Finally, if one showed me a graph of the HP curve for a given engine, I should not need to see the torque curve in order to understand "how hard it will pull" or "if it has high "torque" at low rpm", etc. It's all there. HP curve. It shows how much horsePOWER an engine makes throughout its rev-band. People are just not trained and used to making sense out of an HP curve at mid and low rpm, or they are confused about the relationship of torque and power altogether.

The same would apply for a graph that included only the torque curve of a given engine. You should and could be able to figure out everything about that engine's character HP-wise.

-----

Now for variable valve timing. A little clarification here as well. To understand VVT, one has to understand what kind of engine Honda used to make. Or even better, what kind of engines Alfa Romeo used to make. They were mostly small in displacement and they were almost always "high revving". High revving means that they made great power "up-high" but not good power "down-low". But enthusiasts loved that high revving character of those engines. Just like enthusiasts love the tight suspension feeling even though it sacrefices ride quality. Same thing. Since Enzo Ferrari used to drive and race Alfas, when he made his own car company he pretty much followed that mantra. To this day. All Ferrari engines are high revving engines. The only reason no one is complaining about power at low rpm (rather lack thereof), is because Ferrari used displacement to minimize the disadvantageous characteristic of a gas engine (especially one without VVT technology) to not provide good amounts of power at mid and low rpm. A big engine will pull hard everywhere. But in the case of Ferrari, it will pull like the devil at high or very high rpm. Again, in the case of Alfa and Honda, they did not have the advantage of large engines. They did not make the cars for them in the past. And that's mostly but not wholy true today for these two.

Then VVT came. What VVT did for manufacturers that sold small cars was to even out the torque curve mostly. I mean if you ever drove a 1980s Alfa Romeo Gullietta or an Alfa 33 you'd understand that...there was no power at low rpm Some engines were basically unusable. Then after 4500rpm, that thing would fly and sound like a race car.

So now with VVT engineers (among other things) found a way to solve a good portion of the "if you want high rpm power, forget low rpm power" issue.

BUT!

If VVT were applied on...mainstream engines, it was possible to make that torque curve be flat. By mainstream engines I mean those that peaked on their HP level at 5800 rpm and peaked their torque rating at 3000 rpm. A good example are the 4 cylinder BMW engines we never see here.

IF VVT were applied on high revving engines, it solved some of the "lack of power at low rpm" issue, but made even MORE power at high rpm, at even higher rpm than before! Why? Well, because engineers now could design a 2L engine and have it rev at 9K rpm and make very high specific power and still have it barely drivable and tractable at 2500 rpm. It it were not for VVT, the latter would have been impossible.

So, that is why, you wrote:

"My point is i-VTEC can generate lots of horsepower, but not lots of torque from a small displacement engine."

In truth VVT has helped engineers find more power at low and mid rpm (torque as you call it), but not very significant amounts and not as much as it helped them make high and very high revving engines available to the public (because they were drivable at low and mid rpm).