From 1000 rpm to 8000 rpm, available torque and horsepower increase between 6- and 10-percent. Additionally, useful power for high performance acceleration begins at about 3000 rpm compared to about 6000 rpm on the 2000 - 2003 models. This performance improvement at the lower rpm ranges can be attributed to the displacement increase, revised valvetrain tuning and the lower gear ratios on gears one through four that help magnify the engine performance gains.

So it looks like 3000 RPM's will be the Vtec # .....

For more info see:


http://www.fast-autos.net/honda/04hondas2000.html

See here too (good stuff!!):

http://www.vtec.net/articles/view-article?...6&page_number=2

more good stuff:

http://www.vtec.net/articles/view-article?...ticle_id=146907

Eliot

 

"...Additionally, useful power for high performance acceleration begins at about 3000 rpm compared to about 6000 rpm on the 2000 - 2003 models. This

performance improvement at the lower rpm ranges can be attributed to the displacement increase, revised valvetrain tuning and the lower gear ratios on gears one through four that help magnify the engine performance gains."

So does that mean VTEC kicks in at this range?

 

That info came from one of the other articles ... see the links; it is clearly stated in one of the articles.

edited:

In the the last link above it states:

 

Impressive.

 

I highly doubt that VTEC will kick in at 3000rpms. That is way too low and would cause the engine to bog really bad. The lowest VTEC engagement point I can think of on any Honda engine is the GSR which activates at 4400rpms. I think they mean it comes on strong at 3000rpms due to its bigger displacement and more available torque down low as opposed to the 00-03 which really start to get going at around 6000rpms.

 

Bold prediction: VTEC will kick in at 5300 rpm.

 

I really really doubt that Honda is using the same cam lobe as the one in the MY00-MY03 s2k. The only reason it'd bog using these cams is because it wasnt designed to. Different lobes can obviously be made for VTEC to kick in at 3k and be successful in making power and not bogging.

Honestly, if VTEC were to kick in at 3k I'd find that to be really "watered down." IMO, i think its just amazing hearing VTEC at the RPM's it does. Lowering it to 3K is just well....wierd. But that's just my opinion.

I think VTEC is going to engage at somewhere in 5k as well but if it's 3...that will be a really bad move on behalf of Honda of America I think.

 

There is no way they could lower VTEC and keep similar gas mileage, so I would put a lot of money on it being in the 5k range.

Blake

 

I agree - the cams have been revised, and the VTEC point will be revised as well. But the 3K guess is not a reasonable one - remember that VTEC is dictated about the physics of the intake flow optimization, Helmholtz resonances, etc. The switchover point is optimized for power baed on those parameters, where the long vs short runner and lift/duration are factored in. This is a dynamic model, not a static one, and too much VTEC too soon would likely be more harm than good.

The new direction emerging is infintely adjustable control of the intake, cam intake and exhaust timings, lift and duration, and...get this....the use of solenoids to control and replace the mechanical camshaft as we know it! Yes, a powerful solenoid would do the valve control - obstacles include size and the power draw to activate solenoids of such capability.

Imagine if you lose a ground or something craps out - you could lose the engine ina hearbeat, so my guess is that they would also need a fail-safe mechanism that shuts the valve pronto!

 

Ok my question is does this mean the 2004 is faster than the 2003 thats all I need to know....I need numbers 0 to 60 , 1/4mile times and also topspeed......