Alright, I didn't realize until recently that the new TL's were VTEC as opposed to
i-Vtec. I used to own a 00 Civic Si, and it used to have a crossover point on the cams of I think 5600 rpm where it switch over to the bigger lobes, and it sounded pretty mean too. I am not all that familiar with how "i-Vtec" works, but from what I have heard it gets rid of having a set crossover RPM for the switch to the higher cam lobes. Anyways, since I figured the TL as a new honda/acura it would have iVtec but which would explain why I have never heard the kick ass vtec crossover, but everywhere I have look it says that the TL just has a Vtec engine. So....I guess my question is what happened to the crossover? Is it there and I just don't hear it? Have they started calling iVtec just regular Vtec, or does the TL not use two different sets of cam lobes like the Civic SI did? Any answers would be appreciated.

 

Why do you "need" to hear it, as long as it does it's job?

A bit silly to me.

I have a Type-R and you definitely "feel" it at crossover, but it's nothing I'd look for in a luxury-sports car. Heck more aggressive cams and the R is a monster with even more noticeable crossover. But, I'd much rather have a seamless crossover and smooth power delivery.

Next you'll be asking about Vtec crossover indicator lights... Never heard that before.

 

Thanks for the smartass reply although it was definately not an answer or an explanation to the question posed. Regardless of whether or not I like how the crossover sounds, the question remains why does is it apparent in one car and not the other. All the B and H series Honda VTEC engines have a very distinct and audible point at which the higher lobes switch in. However, I haven't noticed this on the TL. So the question still is does it have a crossover? And if it does where is it at on the RPM band?

 

TL has VTEC. TSX has i-VTEC. VTEC in TL switches at 4700RPM.

I'm not sure why they didn't put i-VTEC on TL. From what I've read, i-VTEC increases low end torque in additional to beneftis of VTEC.

 

First off I'm not trying to give a "smart assed" reply,

Just because you can't hear it or feel it doesn't mean it's not there. Nor would you want it or to feel or hear it.

And definitely you have a crossover and especially illustrated in your literature provided by Acura in their brochure.

But, the smoother the better is what I'm trying to get at here. You don't want some huge gap or some neccessary "feel" or "sound" at crossover. It should be as seamless as possible.

When B18C series motors are tuned and especially C5's they look to get as smooth and seamless a line at crossover as possible. When the primary lobe is almost as aggressive as the secondary, the transition is almost seamless as in say a Toda B or C.

So to answer the question "is it there?" there most defintely is. Is it as distinctive and agressive as the old and at this point crude B series? Geez I'd hope not, or at least as little as possible and especially for a luxury/sports/semi-performance minded sedan.

Sorry if I came off as a wise-ass, but my experience is with the youth of today where "noise" & "looks" alone are the prerequisite.

For an explanation of the Vtec as opposed to the iVtec motor, iirc there is a good description at "How Stuff Works".

Best of luck.

 

As for Vtec as opposed to iVtec, as I understand it plainly: iVtec is a more continuously efficient version where as Vtec is a more performance minded version.

If I'm incorrect or clouded I invite someone to clear things up for me.

 

Thanks for the polite response, I appreciate it. Your 2nd post actually helped out a lot.

 

When my TL-S was stock, I had to carefully listen and feel for the cross-over. It's tuned for a combination of comfort, noise reduction, and performance. The way my car sits now, I can feel and definitely hear (you would have to be deaf not to hear VTEC engage in my car) the cross-over.

However, one of the main reasons that you can feel the cross-over better in, say, the B18C5 than the J32A3 is because of the cam configuration. The DOHC B18C5 utilizes efficient valve timing on both the intake and exhaust ports, whereas the SOHC J32A3 only does it on the intake port. This is why headers help so much on the J32A1 and A2 (wish I could say the same on the A3), because the restrictive stock exhaust manifold is replaced with much freer-flowing aftermarket headers which utilizes more efficient exhaust flow; a poor man's DOHC VTEC, if you will.

Had Honda/Acura put DOHC in the J-series, it would've been much better. However, as an engine family that goes in A LOT of the Honda/Acura vehicle line-up, it was in their best interest to save costs. SOHC is cheaper to produce than DOHC. The J-series goes in vehicles such as the Odyssey, MDX, Pilot, etc., most of whose owners won't even know what SOHC and DOHC stand for, much less the differences between the two. So you can see why Honda decided to go SOHC on the J-series.

Is it important to hear it? Not necessarily. But if you're a VTEC whore like me, and addicted to the sound of VTEC, then it kind of becomes a part of the driving experience, expecations, and enjoyment.

And before you ask, no, you can't do a DOHC swap on the J-series. The closest candidate is the C32 NSX heads, but the block configuration is different and would require a lot of custom fabricating and machining.

As H-T guys would say, VTAK ownz j00!

 

Ah okay, I forgot all about SOHC Vtec. I am guessing the J32 is in the 04 TL and thats its SOHC which explains why the transition isn't as distinct as the old DOHC B16. Thanks a lot.

 

Hey Pure,
Thanks for the lucid explanation. That clears up one of lifes mysteries for me. The TL is my first and only Honda product (except for a lawnmower and a "Honda 65" a long time ago), so I have some "catching up" to do.

 

i used to own a 00 Si too, it definetly isn't as noticable in feel as it was in the Civic, but if you do listen you can clearly hear when it switches to the larger lobes.

 

I also owned a '99 SI with the B16A. I found the change over into VTec, if you will, is very noticiable in the TL. I do not believe it's at 4700 rpms as some one stated, but closer to 5600 rpms. You can probably notice it best if you manually drop your transmission into second and punch it at about 4500 rpms. You will notice a dense acceleration until 5500 rpms, where the cars acceleration will dramatically increase as well as the common VTec growl. An intake would increase the growl significantly per my experience with my '99 SI.

 

yeah, its around 5600-6000 rpms, forgot exactly where it is

what you get around 4000 rpms is the 2nd plenum opening for more air, kind of like the GSR had with the butterfly valves

 

http://www.hondanews.com/CatID3014?m...48681&mime=asc

It says 4700RPM

 

"The VTEC changeover point occurs at 4700 rpm, and takes just 0.1 second; it's undetectable to the driver."

Yep, 4700 RPM in the A3. It was higher in the A2, like 5400 RPM.

 

Install the injen or aem cai and you will definitely hear and feel the vtec crossover point.

 

The torque curve of the J32 engine is so flat that vtech engegement is almost un-noticeable.

 

I ran across this article the other night in the Canadian Driver Webzine . Thought it might provide a bit of additional insight.