Now bare with me here I'm a Honda guy I've had Prelude Type SH, S2000, Acura CL-S 6Spd, and a 95 civic w/ b16b. OK... im was in a major car accident in my civic 3 yrs ago that left me as a paraplegic. the fit is the perfect car for me. honda pays up to 1000.00 towards modifying the car with hand controls. anyway i digress. why is there no vtec changeover sound in the L-series motor? That nnnnnnnDRRRRR great vtec sound. I ask this because a d16y8 (97-02 ex sohc vtec motor) is silent too until u put an intake on the car an u could hear vtec changeover. In the fit even if you add an intake you cant hear it so what type of vtec system is in this motor? is it like vtec-e like from the civic HX where it just goes from 8 valves down low to 16 valve at hi revs? thx for any help

 

yup the cam profile is the same, and the only change is the number of valves operating, 12/16 at light loads and low rpm only 1 intake valve is working and the 2nd valve joins the party between 2200-3500 rpm depending on load.

as for the sound, it's probably because the switchover occurs at such low rpms that even though there is a change in engine note, it's not loud enough to hear, at WOT the 2nd valve activates at anything over 2200 rpm, now if you're going WOT most likely you are above 2200 rpm to begin with so the change in note would occur at the exact same in time as the change in note due to wider throttle opening, hence why it's so difficult to hear

 

you mean no change in intake valves? vtec just changes the exhaust valves in the fit?

 

Either way, it is a 12v motor from 0-2300 Rpms DEFINATELY. And it is Variable activated from 2300-3400 (On or off meaning 12v or 16v).

That variable activation between 2300-3400 depends on throttle demand and the computer responds by activating VTEC during 2300-3400 depending upon demand.

After 3400rpms No matter what throttle response VTEC will BE ON!

(But I'll tell you from first hand experience and a VTEC light on my FiT, it is hard NOT to get Vtec on during those variable rpms (2300-3400) unless you drive with a feathers' weight on the throttle and drive slower than the slowest grandma you know!)

All in all the way that I Drive and the way that MANY do, you will be in VTEC from 2300 rpms ON during normal regular driver "acceleration".

Unless you are "crusing" on the highway in 5th gear and hardly touching the throttle, and the rpms' happen to be below 3400.

 

That last part is probably true.... I never thought of it as that, but I see what you mean about that.

I have a manual I should start in 2nd at WOT and see how it sounds! I'll report back. (I have CAI and Catback and Crank Pulley)

 

Props to being a paraplegic and able to drive! Quite an accomplishment to me.

The cars you listed have the performance vtec, the Fit has a economical vtec.

 

Ive never been in a non-DOHC VTEC car (ie, Integra GSR, Type R, Prelude VTEC) and heard the VTEC X-over?

 

With a intake you can hear high-cam in every SOHC ive ever seen.

I drive a 87 Civic that is 12 valve. Below Vtec in the Fit i can definatly hear "the 12 valve sound" and hear a change when it switches to 16.

 

Economic? You mean better on gas..... It's just the cam profile no?

 

Maybe thats why, Im not sure Ive been in a SOHC VTEC that had a diff intake (obviously the DOHC cars you can hear w/stock intake).

 

it sounds something like that

 

I didnt here on that one...

 

i too did not hear the "sound"..

is that for real?... the car must have monster engine....

 

I would suspect the reason you can't hear the switch probably has more to do with Honda's decision to focus more-so on economy, but it doesn't make sense why the rest of the car is fairly performance oriented (for a B-segment car anyway). I suppose you could always modify the stock airbox to get the sound you want

 

simply put

L15 Vtec IS VTEC-E (economy)

D16Y8 VTEC is VTEC-II (power)

 

0:21 and 0:44 You can deffinatly hear the High Cam Switch
Video - Nice Dyno Video.. U can Hear Vtec Kickin In.

 

Intersting I owned a 2004 Civic Si and I never noticed anything like that.

All this talks of sounds makes me miss the woosh of a turbo wastegate

 

The I-Vtec cars are harder to hear, becuase first they change the actual cam timing, by rotating the cam gear, then they actualy switch to High-Cam Later in the RPM scale. Ive riden in a RSX-S with a AEM CAI and you could hear High-Cam switch but it wasnt extremly loud.

Stock air intakes are baffled and designed to reduce noise, making the car quiter,so naturaly you loose the Vtec X-over noise.

 

Thanks. it's been a long 3yrs lol. I tried out one the othere day and everything fit...lol. i have pix.

 

Here's some info for anyone that’s like me and want to learn more about how VTEC work.

Traditional VTEC system (B18’s with VTEC), each cylinder has 3 intake valves and 3 cam lobes: two (normal/small cam lobes) that are for normal driving (0-4500 RPM) and one (power/large cam lobe) for more aggressive driving (4500-redline) When the engine reaches above 4500 RPM, a pin is hydraulically pushed to lock ALL cam lobes together. Therefore, only the LARGE cam lobe is used, which means more power.

Here’s a video that explains everything PERFECTLY:

http://www.honda-marine.com/video/VTEC.wmv


In the L15A VTEC system, it uses 2 valves for exhaust at all times and it alternates between one and two valves for the intake side. For the L15A VTEC engine, at normal driving, the engine uses one intake valve. When more power is needed, the second valve operates to increase the amount of airflow into each cylinder since valve opening times are shorted with RPM increases. (That sounds really confusing even to me )

Here’s a link where you can learn about the different models of the “1.2l, 1.3l and 1.5l, all SOHC i-DSI designs and finally a 1.5l SOHC VTEC version which is not i-DSI.”

The Truly Amazing Honda Fit/Jazz


Hopefully this helps!!



PS: if I’m wrong, by all means, correct me. I want to make sure that everyone gets the right info including me.