i have been the proud owner of a 4th gen VTEC Prelude for 6 months now. I installed an AEM cai about 4 months ago. Now any 4th gen H22A owner w/ intake will tell you it pronounces VTEC like no other. Flooring it in 2nd gear at about 2500 rpms results in a deep "woooo" growl from the intake that intensifies all the way up to VTEC engagement at approx. 5k. This is when it screams more of a "waaaaAAA!!" tune all the way to redline.

however, if youve ever driven a B-series engine w/ intake you'll notice a different scenario. I have the most experience w/ the B18c1 cuz my good buddy had a GS-R we loved to push to the limits (although i have driven an s2000 to its limits once)

What ive always noticed is how the B-series VTEC isnt quite as pronounced as the H22A. There is not as much of an obvious switchover point. Its not a bad thing, its just as strong but the VTEC seems more implemented into the whole rev range. You will hear the VTEC engagement but its just not the same. I was wondering how these systems differ in that matter. Can anyone relate to what im talking about?

 

I hear ya, the prelude motor is larger and uses larger intake/exhaust valves so the sound is more pronounced.

 

what would sound better a short ram intake or cold air???

 

one reason you may hear a difference between the gsr and the prelude, is the gsr intake runner butterflys open after vtec engagement. for example the vtec engages at 4800 rpms and the butterfly opens at 6000 rpms. so when you hear vtec engage its not quite as loud as the h22.

(note: rpm values may not be accurate for the the b18c engine, used as an example. so save the flames if they are wrong.)

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 93preludevtec &raquo;</TD></TR><TR><TD CLASS="quote">one reason you may hear a difference between the gsr and the prelude, is the gsr intake runner butterflys open after vtec engagement. for example the vtec engages at 4800 rpms and the butterfly opens at 6000 rpms. so when you hear vtec engage its not quite as loud as the h22.

(note: rpm values may not be accurate for the the b18c engine, used as an example. so save the flames if they are wrong.) </TD></TR></TABLE>

Yeah that's true...and on the H22a the butterflies open BEFORE VTEC, hence the sound

Here's a post I wrote up on PO.com a while ago:

Ok out of being sick of people quoting the wrong information about when the Secondary Intake runners open on both the H22 and H23 engines, as well as when VTEC engages, I make this post.

From my trusty helms here is the facts on the H23

H23A1 IAB Valve OFF: 4,800 RPM

Yes that's right boys, your H23 secondaries do not open at 4k for the torque monster etc etc....

For the H22A1:

H22A1 IAB Valve OFF: 4,600 RPM
H22A1 VTEC Engagement: 4,900 RPM

That's right, not 5k, not 5200, not 5500. Someone can post the H22A4 figures that would be great.

NOW, let's see the 4,600rpm secondaries in action! Here is a video of my "stock" lude on the dyno. Listen closely and you can hear the secondaries open up just before VTEC. It's actually pretty cool, because it sounds like VTEC has engaged, then about 2 seconds later you hear it REALLY engage. It's pretty cool, and I think helps describe the difference.


http://satan.higginstribe.com/satan_dynorun.mov

Enjoy!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by post above &raquo;</TD></TR><TR><TD CLASS="quote">H22A1 IAB Valve OFF: 4,600 RPM
H22A1 VTEC Engagement: 4,900 RPM</TD></TR></TABLE>

But on the stock tach is reads it as around 4,900.

I don't know if teh closed deck H22A1's sound different than the H22A4 open decks, but in my mind the B16 has a really monsterious sounding engine compaired to the H22A4. The growle in VTEC is just damn scarry. Maybe I just haven't heard my car by a b16 hitting VTEC w/o me in my car to be hearing correctly.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by rjr162 &raquo;</TD></TR><TR><TD CLASS="quote">

But on the stock tach is reads it as around 4,900.

I don't know if teh closed deck H22A1's sound different than the H22A4 open decks, but in my mind the B16 has a really monsterious sounding engine compaired to the H22A4. The growle in VTEC is just damn scarry. Maybe I just haven't heard my car by a b16 hitting VTEC w/o me in my car to be hearing correctly.</TD></TR></TABLE>

it just sounds like a single runner manifold, just like a type R

there is nothing scary about a b16 except the fact that they make alot of noise and go no where fast with just an intake

 

The factory tachs can sometimes be off by a couple of hunderd RPM, that includes most cars that i've worked with. VWs, Fords, Chevs, ect. Mustang tachs being off as much as 500-700RPM.