This was supposed to be just about the perceived change during VTEC crossover, not f-series vs k-series. Oh well, I'll chime in anyway.

The f-series and k-series are going to have very similar peak power potential. This shouldn't be surprising; they're both 2.0-2.4L 4cyl Hondas designed and built in recent years with an eye to performance. An f-series engine is going to make more power stock. It's a more extreme design with more exotic materials used in its construction. It's more expensive and time consuming to make. The k-series is the future of Honda. It's easier to make, provides better economy, provides better drivability, and has lower emissions. This is the benefit of camshaft phasing (contrary to what Toyota would have you believe, camshaft phasing is not a ticket to big power).

Someone once said that the f-series was a dead-end design. In terms of factory performance, they were probably right. Don't expect to do better with the k-series, though. The gains and improvements in coming years are going to be related to emissions and economy.

The f-series is a better all-out performer while the k-series has other positive attributes.

 

toda n2 kit is putting out about 230 whp, FI I think they would both be similar, but by far the RSX responds to Mods Better and seems to have more NA potential.

 

any dynos on that? I remember someone saying something about 270's but never 300, what was it that church automotive got out of the f22c? Didnt that one kid, s2k@16 or soemthing make like only 220whp on the inline pro 2.5 kit?

 

i'd have to search for it. lol, it might just be easier for me to find UL's post where he talked about this.

 

The F20C may make more power, but when you factory in cost the K20 just makes so much more sense.

Totally swapping out my F for a K-series and making my car FWD.

 

To (briefly ) get back on subject, as someone else pointed out, if you're less than full throttle, the effect will not be that noticeable. The car will only give you what you're asking for. Light throttle applications at the VTEC transition won't show you much. When I've done this, I could detect a slight shift in the exhaust note and I could tell the engine was breathing a little easier but other than that, not much.

It's also a matter of what you're used to driving. This is the first performance car I've ever owned. The first time I stepped down on it after passing the recommended break-in mileage, I started in 3rd gear at about 2500 rpm's. Acceleration was Ok but nothing to write home about. When it crossed 6000 rpm's, it was like someone installed an entirely different engine. The effect, for me, was and one hell of a lot of fun! Now that the car is just over a year old and I've got 22+k miles on it, the VTEC transition isn't nearly as exciting. I still enjoy it but I've also gotten used to it. I don't feel like I'm driving behind the car any more.

I think it's also a matter of how much you've built up the transition in your mind. After reading all the "oooo's and ahhhhh's" of how "great" it is from everyone around here, the real thing might be a bit disappointing.

FWIW!
Drive Safe,
Steve R.

 

So, after 4 days of this thread, have you tried full throttle yet? I think I did at 601 miles

 

First: I, two drove a B-series for several years before picking up an S2000 (specifically, a 1997 Integra GS-R with a B18C1). While the difference in sound was more acute, owing in some way I'm sure to the two-stage induction system, I would not argue that the surge was more noticeable in the Integra than it is in the Honda. Though we are arguing perception here, under WOT the VTEC crossover feels every bit as noticeable to me. I suspect, though, that we can settle this argument quantitatively by comparing stock torque curves.

Second:

Power is made from the following ingredients:

Displacement
RPM
Effective compression
Volumetric efficiency
Mechanical efficiency (i.e., low pumping and friction losses)

The latter three are usually bundled into MEP, or mean effective pressure.

The head (and the piston design, and intake/exhaust design) is responsible for volumetric efficiency and mechanical efficiency. As someone has already noted, port size will determine the maximum power an engine can make (as choking will cap the volumetric flow rate into a NA engine). So, if it can be shown that the F20C/F22C head indeed flows better than the K-series head, it seems obvious that at the same engine speed and displacement (and compression!) in a highly-modified version of both engines should result in more power for the "F"s. I don't know that such has been established, but the following makes good reading:

Some flowbench results for the F20C:

http://e30m3performance.com/tech_articles/...w-1/chart-4.htm

A very interesting look at F20C heads on TOV:

http://www.vtec.net/articles/view-article?...0&page_number=1

 

You waited "that" long? I think I was at 600.1!

The first lier doesn't stand a chance!

Drive Safe,
Steve R.

 

I felt the VTEC crossover surge was much more dramatic in my F22C 05 than my F20C 01.