Hi,

I have been reading here about the VTEC kicking in (VTEC shifting to high performance) at around 4800. I decided to try this on my TL-P. I SSed to third gear from the ramp onto the highway and floored it...the RPM rose to 5,000 rpm and then the rate of RPM increase slowed down. I then SSed to 4th ..

I was so focused on the rpm that I failed to notice wether the VTEC kicked in

Is this how you get VTEC to kick in? Is the RPM for VTEC to kck in different on the TL-P?

-Tom

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according to my Vafc reading, it is 3500rpm for 99TL
not sure if it is the same for the 00+ TL

 

i believe 02 is at 4500rpm

 

stop looking and start listening you should hear a nice throaty hum that you normally dont hear. wont be much of a roar since the engine was designed to be quiet -- unless you change your intakes and exhausts .. obviously, you wont hear it if your stereo is blasting either

alternatively, if you get a clear enough strip of road. stick to the lower gear and 'ease the pedal down' .. gradually doing more. that way, you have enough time to actually 'hear' the tonal difference as it steps over. if you punch it, it'll go all the way up from the get go and then you wont notice the sound difference as much.

 

As the engine accelerates through 4400 rpm (4800 rpm on Type S), the intake rocker arms transition to actuation by high-lift, long-duration cam lobes designed to optimize high-rpm output. VTEC™ delivers substantially more horsepower from 4600 rpm to 6300 rpm redline (6900 rpm redline on the TL Type S) and provides a considerable torque increase both at low and high engine speeds.

 

I don't know, but I always thought, VTEC was design to save gas

so from 4600 rpm to 6300 rpm in VTEC mode your engine is running at regular maximum power. Under 4600 most driving you are running a lower profile to save gas. Of course VTEC allows you to have both profiles, so you get the best of both worlds.

 

Apart from saving gas, the lower profile cam timing also maximize the engine's torque output below 4600 rpm (i.e. low and mid range). Running in VTEC mode (agressive timing cam) at low and mid rpm range will kill the torque output completely.

 

True True

 

Hi,

Writing from Japan.
Since Saber has J25A engine that is only for Japan, this information may not be useful for you, but HONDA explains the technology of J25A as follows.


The point that VTEC changes the timing from low to high is 4,300RPM and the point that a valve in the intake manifold open for making high volume chamber is 5,000 RPM.

I like HONDA as the engine technology is great.
I could also find out an explanation for Integra Type-R.
It is amazing that the VTEC changes the valve timing at 6,000RPM and the as the red zone begins 8,400RPM.


Edited by Bitium

 

haha...well...basically the VTEC works thru the whole rpm range...

but ours the VTEC is in full strength starting at 4000rpm above...
actually u will feel the noise and power above 3500rpm...and the strength of VTEC is it won't slows down at high rpm while the ordinary engines are so...