2200 rpm vtec doesn't really make sense.

[i-WERKS]

As most people have stated, the vtec point for the K20A3 is 2200 rpm. This doesn't really make sense since most if not all people would not drive below that point.
Think of this. When you're accellerating, you'll shift gears say at the lowest 3000 rpm. The next gear would put you into approx 2200 rpm which is already in vtec.
If you're cruising at say 60km/h or 40mph (speed limit on local streets in toronto) in order to be below 2200 you'll have to be in 5th gear. I'm not sure how everyone else drives but I'm still in 4th gear when cruising at that speed.
So really, what's the point of having the vtec engagment point at 2200 rpm when really you stay above that after 1st gear. It won't save you gas since you don't drive below 2200 rpms.

[Chrisbgft]

IMO...i think the VTEC kicks in around 2200rpm at WOT. If u have I/H/E, u will notice how when at WOT from 2200 til redline the car sounds as say a B16 would sound like from 6800 til redline. To me its a more gradual VTEC all through the RPM Band....maybe i am just blabbering if it doesnt makes sense just tell me STFU...lol.

[Peking]

It makes plenty of sense :D , giving more torque through all rpm. Along with other benefits.

[ahhhonda]

someone already posted this link somewhere else, but here it is again, it pretty much explains how our engines work. LINK (http://www.hondata.com/techk20general.html)
If you don't wanna look, then here's the important part..

Under 2200 rpm, this engine is a effectively a 12 valve engine, and over 2200 rpm it is a 16 valve. There is no VTEC mechanism on the K20A3 exhaust valves.

[SiMPLE_SiMON]

Think of it in reverse of the typical Honda VTEC. The K20A3 uses VTEC as a way to get great emissions and fuel economy when idling. The rest of the time during normal driving, your on the regular cam. It seems like that's what Honda had in mind.

[i-WERKS]

Originally posted by ahhhonda
someone already posted this link somewhere else, but here it is again, it pretty much explains how our engines work. LINK (http://www.hondata.com/techk20general.html)
If you don't wanna look, then here's the important part..

Under 2200 rpm, this engine is a effectively a 12 valve engine, and over 2200 rpm it is a 16 valve. There is no VTEC mechanism on the K20A3 exhaust valves.

What's the point of running 12 valves under 2200 rpm when the only time your there is accellerating from 1st gear? It's kinda pointless if you ask me. There wouldn't be much of a difference between that and having vtec on right from the idle.

[BlasTech]

Depending on your wheel diameter, you can cruise through the hood at 30mph in 5th at stay right below 22K.

The point for our vtec is cleaning up idling emissions, which are the worst emissions cars produce, and fuel savings, which offsets the aggressive gearing (for a civic) in our EP's.

The power tweak for our engines lies in the "i" part of the i-vtec, continuously variable timing.

[!@#$%]

when you are in STOP AND GO traffic, I hope you dont feather the clutch over 2200 everytime you take off. I think the fuel savings for people in the city who drive in traffic benefit the most from the 2200 vtec engagement. That way for that hour or so of traffic your car will run off of 3 valves. Better city mpg, but not much.

[bobdobbs]

Originally posted by i-WERKS
So really, what's the point of having the vtec engagment point at 2200 rpm when really you stay above that after 1st gear. It won't save you gas since you don't drive below 2200 rpms.
The biggest waste of gas and a large source of pollutants is at idle. At low-RPM your engine isn't working hard enough to burn up all the hydrocarbons. The problem with low-RPM conditions is the velocity of the air/fuel mixture isn't high enough to work well with a performance cam with high lift and long duration. In older cars, with only one cam per valve, you could swap in a higher-lift/longer duration/greater overlap cam to produce more power up top, but your idle would be so lumpy and stinky, you'd really only want to do it on a track car.

So, think of it this way: The reason you've got 160 HP is because your car shuts down some of the valves when they aren't needed. If they were all working, all the time, the engine wouldn't pass emissions, and your idle wouldn't be sewing-machine smooth like it is now. Honda would have to then compromise higher-RPM performance (even more than it is) to pass emissions and you're back to 1988 and 112 HP (or whatever a 2L engine did in those days).

[Zero Three Si]

Originally posted by bobdobbs
The biggest waste of gas and a large source of pollutants is at idle. At low-RPM your engine isn't working hard enough to burn up all the hydrocarbons. The problem with low-RPM conditions is the velocity of the air/fuel mixture isn't high enough to work well with a performance cam with high lift and long duration. In older cars, with only one cam per valve, you could swap in a higher-lift/longer duration/greater overlap cam to produce more power up top, but your idle would be so lumpy and stinky, you'd really only want to do it on a track car.

So, think of it this way: The reason you've got 160 HP is because your car shuts down some of the valves when they aren't needed. If they were all working, all the time, the engine wouldn't pass emissions, and your idle wouldn't be sewing-machine smooth like it is now. Honda would have to then compromise higher-RPM performance (even more than it is) to pass emissions and you're back to 1988 and 112 HP (or whatever a 2L engine did in those days).

While all this is true....that 1988 civic will whoop the ep. I just read a magazine last night and the 1988 si weighed in at like 2100lbs and the 2002-2003 weighed in at 2600lbs. Granted the 500lb weight they run very close but the 1988 still wins in the twisties. But we have to save the planet because of the ozone hole.

[bobdobbs]

Originally posted by Zero Three Si
While all this is true....that 1988 civic will whoop the ep. I just read a magazine last night and the 1988 si weighed in at like 2100lbs and the 2002-2003 weighed in at 2600lbs. Granted the 500lb weight they run very close but the 1988 still wins in the twisties. But we have to save the planet because of the ozone hole.
I wasn't talking about an '88 Civic, but an '88 2-liter engine, in general. The biggest advancement since then is variable valve lift and timing, which is why engines of identical displacement are 50% more powerful and cleaner-running now than they were 15 years ago. In the future, I'd expect to see continuously variable valve lift without camshafts, but with hydro-electric or electro-magnetic lifters. I believe Mercedes has these working now.

By the way: Who was the first manufacturer to offer variable valve timing??? If you say Honda, you'd be wrong. :D

[BlasTech]

That article was enlightening, but remember, the EP3 does still have a better power/weight ratio than the 89si.

One differnce was gearing, as they pointed out that the 89 could go much faster in 2nd than the EP3, but Hondata is the equalizer for that issue with just a few more rpms.

The other issue was lateral traction, and there are some who would argue that a different suspension setup might do better, but I would say an LSD would really solve the problem, though that would kick the EP3 into a different competitive class, where it once again be struggling.

All-in-all though, the EP3 is a modern car, with modern amenities and advantages. Pick one for the track only, it might be the 89. Pick one for daily driving only, it might be the EP. Pick one for both...

[bobdobbs]

Originally posted by BlasTech
That article was enlightening, but remember, the EP3 does still have a better power/weight ratio than the 89si.
Is it online?

[BarracksSi]

Originally posted by Zero Three Si
While all this is true....that 1988 civic will whoop the ep. I just read a magazine last night and the 1988 si weighed in at like 2100lbs and the 2002-2003 weighed in at 2600lbs. Granted the 500lb weight they run very close but the 1988 still wins in the twisties. But we have to save the planet because of the ozone hole.

The extra weight is for crashworthiness and soundproofing (generally), not for the 2200-rpm i-VTEC.

Sure, it would be fun to put even a K20A3 in that '88 Si, but for another comparison, put that '88 engine in the EP. My goodness, what a sloth that would be.

It's selfish to want more power despite in spite of what's best for everyone else. I'd rather have a little less power if it means that I don't have to wear long sleeve shirts and huge hats to go outdoors in the future.

[potator]

So who was the first manufacturer to offer variable valve timing???

[bobdobbs]

Originally posted by potator
So who was the first manufacturer to offer variable valve timing???
Alfa Romeo, in 1980, almost a decade before Honda.

I have an Alfa Romeo sedan, with a dual-overhead cam engine, aluminum head and block, 5-speed fully-synchronized transmission, four wheel disk brakes, independent suspension, unibody construction, with crumple zones. Made in 1965. :D

[myyellocrx1]

That's why i keep my 89 CRX SI.... WHOLE LOT OF FUN TO DRIVE!!!

[Zero Three Si]

Originally posted by bobdobbs
Is it online?


I'll try to find out which article and which magazine I was reading. I'm sure it's online, I just don't recall what magazine it was. Like the guy pointed out...if you want a car for the track it would probably be the 88 Si. In straight line speed though, the EP did win.

[sniperSI]

Originally posted by bobdobbs
The biggest waste of gas and a large source of pollutants is at idle. At low-RPM your engine isn't working hard enough to burn up all the hydrocarbons. The problem with low-RPM conditions is the velocity of the air/fuel mixture isn't high enough to work well with a performance cam with high lift and long duration. In older cars, with only one cam per valve, you could swap in a higher-lift/longer duration/greater overlap cam to produce more power up top, but your idle would be so lumpy and stinky, you'd really only want to do it on a track car.

So, think of it this way: The reason you've got 160 HP is because your car shuts down some of the valves when they aren't needed. If they were all working, all the time, the engine wouldn't pass emissions, and your idle wouldn't be sewing-machine smooth like it is now. Honda would have to then compromise higher-RPM performance (even more than it is) to pass emissions and you're back to 1988 and 112 HP (or whatever a 2L engine did in those days).


Amen!

(And honda used vtec before 1991, it was just first introduced to the US market in the NSX in 1991.)

[BlasTech]

We're talking about one of the latest Grassroots Motorsports (the one before the current one)

[IchBinEinSiR]

So, everyone understands that the only reason our cars have a vtech feature is for mileage and emmissions (at idle)... and I believe that the first Honda motors with vtech were also employed for low emmissions and high mileage...

[simann]

they should of just put a K20A2 in our si's and had less aggressive cams and springs....like the GSR to Type-R sorta thing..

another reason i think they put vtec ar 2200 is because if it ecgauged at say 45-5500 rpm's the car would pull hella slow, its slow as it is to a type-s ( my brother has a type-s with AEM sri and HP header) our cars need low end vtec for the extra down low power to keep up with the other cars, and also it doesnt have the mid range lobe like the K20A2 and GSR motors had.:( ;)

[bobdobbs]

Originally posted by IchBinEinSiR
So, everyone understands that the only reason our cars have a vtech feature is for mileage and emmissions (at idle)...
That's sorta backwards. The reason we have vtec is for power. Honda *must* conform to EPA/CARB standards, so the low-RPM efficiency is a must. Honda adds vtec to allow the engine to open up at higher RPMs and produce more power. Just because they have other engines like the A2 that do a better job (with more cam lobes, etc.) doesn't mean the A3 isn't designed to give more power at higher RPM.

[bobdobbs]

Originally posted by simann
they should of just put a K20A2 in our si's and had less aggressive cams and springs....like the GSR to Type-R sorta thing..

The A3 is cheaper for Honda to produce, so they can offer it in a lower-priced car. The lack of vtec on the exhaust cam and the simpler intake cam and a few other things makes the engine less expensive for them. If they just had less agressive cams, but still with the same number of lobes, and vtec on the exhaust, etc., there would be no cost savings. From their point of view, Why bother?

[Dunrick]

remember our i-vtec only switches the engine over to 16v at WOT

so when your daily driving, your not in i-vtec unless you slam on the gas....


lots of people forget that.......

[BarracksSi]

Originally posted by Dunrick
remember our i-vtec only switches the engine over to 16v at WOT

so when your daily driving, your not in i-vtec unless you slam on the gas....


lots of people forget that.......


Makes sense. Why bother with vtec engagement unless the driver's foot is stomping on the gas? Nobody expects, or needs, 160 HP at part throttle anyway.

[IchBinEinSiR]

Our engines are designed to do some "lean burn" running. Any chance that this has something to do with the smell we get?