E30M3

Individual TBs give noticeably better throttle response than using one large TB. Several reasons for this, separate from power curve tuning. The actual runners experience reflection and resonator effects. And you can add a plenum, whose size affects the torque curve. And a secondary intake feeding the plenum which also experiences reflection and resonator effects among other things. You can go for peak HP or area under the curve, etc, depends upon what you are trying to do. My old M3 has individual TBs (factory!!) and it has good torque above 2000, comes on hard at 3000 and revs to nearly 8000. You can cruise around town in 5th at 15-1600 RPMs. 'Course the car has some mods such as running a MAP sensor.

Stan

eyescream

that's what i thought too

StwoK

Ya it's I-VTEC, I = intellegent ! Our VTEC kicks at 6,000 rpm, with I-VTEC it is continous. I-VTEC can very from +25 degrees to -25 degrees depending upon the conditions. This makes it smoother and with more torque at the same time. The RSX Type-S is the first production I-VTEC car.

cdelena

[QUOTE]Originally posted by StwoK
[B]Ya it's

Voodoo_S2K

My bike has them and it runs perfectly fine.

Zoinks

http://asia.vtec.net/article/ivtec/

"The i stands for intelligent : i-VTEC is intelligent-VTEC. Honda introduced many new innovations in i-VTEC, but the most significant one is the addition of a variable valve opening overlap mechanism to the VTEC system. Named VTC for Variable Timing Control, the current (initial) implementation is on the intake camshaft and allows the valve opening overlap between the intake and exhaust valves to be continously varied during engine operation. This allows for a further refinement to the power delivery characteristics of VTEC, permitting fine-tuning of the mid-band power delivery of the engine."

...or from the horses mouth:
http://www.acura.com/model_types/rsx_types.../types_vtec.asp

cdelena

Exactly as I thought, it has nothing to do with transition to the hi-rpm cam.. "i-VTEC system uses Variable Timing Control (VTC) to adjust the phase of the intake camshaft, advancing or retarding cam timing, to keep power output smooth across the rpm spectrum."

StwoK

Yep that's pretty much what I said also.


.
Our VTEC is either off or on whereas I-VTEC is continuous, it's always working! By conditions I was referring to current power demand and rpm. I-VTEC looks at those conditions and retards or advances the timing by as much 25 degrees (- or +). This results in a smoother application of hp and torque in the lower rpm ranges then that of the prior generation of VTEC

StwoK

From Why not V6 S2000 post on 11/11.

https://www.s2ki.com/forums/showthread.php?...&threadid=34512

I said:

[QUOTE]In an earlier post in this theard I mentioned, Yutaka Otobe being directly responsible for the S2000 and the new RSX. In that article he also spoke about his racing days in engine developement. He was on the team that built a first 1.5L engine that broke the 1,000hp mark. At that time dynometers registered only 1,000hp, so they never knew just how powerful that engine was. He also worked on a V-6 Turbocharged 1.5L, a 3.5L V-10, and a 3.5L V-12. He mentioned that today's 3.0L V-10 runs at more than 15,000 RPM. It would appear Vs can run smooth at high RPM(someone said only an I4 could). It would seem to me that I-VTEC is in the near future for the S2000. And once the 4.0L V-8 NSX is released, it won't be long till a V-6 2.5L or 2.8L roadster will be released. NA of course!

cdelena

[QUOTE]Originally posted by StwoK
[B]Our VTEC is either off or on whereas I-VTEC is continuous, it's always working!