I don't know I guess I tend to agree w/style teg.I think everyone is kind of looking at the vtec function backwards,giving you unbelievable top end power,when imo vtec was designed to pass emissions and improve low rpm street driving.If honda just wanted to make the high hp #'s vtec motors make they didn't need vtec to do it,all they had to do was put cams in that match the center lobes from the start.Yes honda redesigned the head for these engines but not because of vtec,it was for the added hp.DSM motors have oil squirters but no vtec function,why because they made the power that necessitated it.The ports on a ls head wont make the power that a vtec head makes,the ports and valves are to much smaller for it to compete w/a vtec head,how was honda able to get the vtec's head port velocity up and improve low speed driving?,by barely opening one of the valves at low rpms.Since the cyl has to draw all it's air from one valve it speeds the air up dramaticly.Put it this way if you elimanated the vtec function as many racers do,where does it affect you?, at low rpms.You'll still have the top end power but w/o vtec on a street car it's gonna take a long time to rev to get there,due to bogging and no port velocity from the big cams.It's just my opinion,I could easily be wrong.

 

It seems to me the point all the anti-VTEC guys are missing is YES you can make an all-out purpose built race engine, better for RACING, WITHOUT resorting to VTEC technology. But the Honda VTEC engines as sold to the public in their passeger cars are NOT racing engines nor were they designed to be. A race engine is designed AND built to accomplish a specific task. That is to win races within a given set of sanctioning bodies specific rules. They DON'T need to idel well or eveny or smoothly, have low rpm torque, get good fuel mileage, last 200,000 miles etc., etc.
They only need to operate in their designed in powerband for a specified amount of MINUTES
A passenger car engine exists and needs to continue to exist in environments a purpose bulit race engine NEVER will.
Therfore I repeat you are comparing "apples and oranges".

 

Ugh.. if people would just read my posts instead of getting all butt-hurt and responding before comprehending what I was am saying this wouldn't be a discussion.

First off, I don't think anyone here is ANTI-VTEC. Personally, I am anti-stupid. Every time I see someone say "then 3rd gear vtec kicked in and I was gone" I want to tear out my eyes so I never have to read it again.

First of all, all of my posts I more than acknowledge that IDLE and DAILY DRIVING GREATLY SUFFERS. Why respond to my post and say exactly what I have said. I am talking about a pure performance standpoint, since majority of people think that vtec someone increases HP, WHICH IT DOES NOT.

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MORE powerful in the least complicated way it could.
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For the god-damn-billionth time. No, it doesn't make it more powerful.


yes BUT the idle would suffer therefor not making it a great daily motor.

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exactly, performance when you need(or want) it, but still retains the same idle and drivability as a non-vtec motor.

...

for the drive home . but in all seriousness, most of us arent building these cars for striclty race aplications. most of us have to drive the car home after speniding the day at the track. thats where the system prevails. no you should never drop out of your power band while racing, but we don't race all the time.
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Yeah, everyone knows this. I stated this at least times in this thread that idle/drivability suffers. If you read my posts again you will see that I am not looking at that aspect because I acknowledge that the idle/drivability sucks when you start heavily modifying your non-vtec NA. But by your reasoning here, if you have a $500 truck and trailer then vtec is useless?

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Great point, vtec isn't the reason the motors where built better, its the power band of the more agressive lobe, and the need that honda felt that the motor should still retain its honda "reliability". thats the only reason the motor where different.
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Exactly. Look at all the vtec engines designed for fuel economy. How many of those have oil squirters

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sure they could have put the vtec system in the same non vtec motor, but would it been as reliable? no, so in turn honda wanted to add vtec to its motors, Knowing that the system would require a stronger motor to be just as reliable.
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It absolutely could be just as reliable. If the redline was unchanged, reliability would be no different than the vtec motors.

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But the Honda VTEC engines as sold to the public in their passeger cars are NOT racing engines nor were they designed to
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That might have been HONDAs intention, but what are the intentions of those here? How many people are greatly sacrificing gas milage, reliability, etc, for a built engine? Most of our cars are hardly what you would call a normal "passenger car" anymore.

All my references to this point have been in the context of a fully built non-vtec vs a fully built vtec. However, if you can stand a rough idle, 200whp is very possible on a daily driven non-vtec engine (NA). Which is competition for a lot of B16 all motor build ups, and the very common poor mans ITR setups. VTEC makes it street drivable, but you can still get the performance and daily drive a non-vtec.


Modified by StyleTEG at 3:41 PM 2/5/2004

 

Maybe you should read the original post again.
His paper is on how you can make a "quicker" honda by starting with a non-VTEC engine vs. starting with a VTEC engine.
An engine is really a glorified air pump, and to have an automatically engaged higher lift cam at your disposal, WILL make more power despite your feelings to the contrary. By allowing more air to pass thru said air pump in a given amount of time. FI works on the same principles.
And I only meant "anti-VTEC" to illustrate someone taking an opposing viewpoint, not that you "dis-like" VTEC engines

 

Yes, but the topic changed to the performance aspect if you were to reread the posts.

My first response was exactly what you are saying

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This could be tough to prove, depending on how far you take it. Since you are looking at street drivable.
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An engine is really a glorified air pump, and to have an automatically engaged higher lift cam at your disposal, WILL make more power despite your feelings to the contrary. By allowing more air to pass thru said air pump in a given amount of time. FI works on the same principles.
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No. You have two exact same engines, except one has vtec. You take away only the low RPM cam profile from the one that doesn't, they will make the same power in the powerband. What will suffer is the low rpm power and idlability. Actually I wouldn't be surprised if the non-vtec one made slightly more power, since the extra rotational mass of the camshafts would be removed.

You are letting in the same amount of air in. Period. Any engine can have a huge wild cam stuffed in it, and let in tons of air in the high rpms, and make tons of power. The lack of having a low RPM profile will only hurt the low RPMs.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">
No. You have two exact same engines, except one has vtec. You take away only the low RPM cam profile from the one that doesn't, they will make the same power in the powerband. What will suffer is the low rpm power and idlability. Actually I wouldn't be surprised if the non-vtec one made slightly more power, since the extra rotational mass of the camshafts would be removed.

You are letting in the same amount of air in. Period. Any engine can have a huge wild cam stuffed in it, and let in tons of air in the high rpms, and make tons of power. The lack of having a low RPM profile will only hurt the low RPMs.</TD></TR></TABLE>
I see where you are coming from and I agree.
But,...........I think you are downplaying the effect of having "only" the high lift cam.
By having only a high lift cam that will allow said engine to be efficent and powerful at astronomical rpms, you "may" not have enough low-end torgue in such a small displacement engine to allow a normal rate of acceleration without extremly low gears to achieve that acceleration. And then to take advantage of the better breathing and more power that a high lift/long duration cam provides you "may" be limited by the same gears that allowed you to accelerate in the first place.

 

I still disagree in relation to gearing

Hypothetical situation, a non-vtec engine that revs to 10,000rpm, powerband starts at 8,000 rpm.

Each gear should be designed that shifting at 10k, you drop to 8k. After fist gear, the low end power doesn't matter.

So make an extremely short 1st gear, then space out the rest for the powerband. There is no problem. Why gear a car around the time its NOT in the powerband?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by StyleTEG &raquo;</TD></TR><TR><TD CLASS="quote">I still disagree in relation to gearing

Hypothetical situation, a non-vtec engine that revs to 10,000rpm, powerband starts at 8,000 rpm.

Each gear should be designed that shifting at 10k, you drop to 8k. After fist gear, the low end power doesn't matter.

So make an extremely short 1st gear, then space out the rest for the powerband. There is no problem. Why gear a car around the time its NOT in the powerband?</TD></TR></TABLE>
My point exactly.
Which is illustrated by the complaints against the S2000.
Which is the most race-bred engine in any honda.
You CAN gear a RACE car for a 10K powerband that's only 2K wide because you don't really need off the line grunt in any racing except drag racing.
But it's not really practicle or "streetable" without ANY of the low-end torgue. And the S2000 HAS VTEC. It would be totally impracticle without it. it would take two weeks for it just to GET to the powerband let alone menoeuver in it, without the low profile cam.
And it's a 2.0L, now a 2.2L, not 1.6 or 1.8.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 4crx4me &raquo;</TD></TR><TR><TD CLASS="quote"> And the S2000 HAS VTEC. It would be totally impracticle without it. it would take two weeks for it just to GET to the powerband let alone menoeuver in it, without the low profile cam.</TD></TR></TABLE>

Exactly my point right there.
Most import heads have 4 vales per cyl,the 2jz has no vtec so all 4 valves open fully during each piston cycle.What happens when you go to the center lobe of a vtec head,all 4 valves open fully.So how do you say that vtec is for high rpm when it really affects low rpm by not fully engaging the other valves?If there were no vtec it would open all the valves all the time,just like an ls head.I think were all pretty much thinking the same way just not connecting w/each other.

 

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But it's not really practicle or "streetable" without ANY of the low-end torgue
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UGH

Oh for the love of god.

This has already been established.

Yes, a high powered non-vtec NA car is not going to be streetable. Why do you keep talking about performance only, and then fall back on streetable when it was never part of your original arguement!?

 

well, getting back to sophisticated's main topic at hand:

"proving that non-vtec applications will work better for quicker hondas with a stronger cam and can still be street drivable"

like StyleTEG said:
"This could be tough to prove, depending on how far you take it. Since you are looking at street drivable"

..and sophisticated hasn't quite mentioned how 'raced out' this non-vtec engine would be, so its kinda hard to give him an outright straight answer unless its broken down into stages of upgrades from a mild to wild engine setup. As far as a wild setup goes for a non-vtec engine, it won't be street driveable friendly at all, and neither would a VTEC engine too [if using camshafts such as Toda killer cams which deletes the use of the primary and secondary lobes completely, making it a non-vtec style engine].

 

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UGH

This has already been established.

Why do you keep talking about performance only, and then fall back on streetable when it was never part of your original arguement!?</TD></TR></TABLE>
Because I get a kick out of how irritared you seem by it. ROFLMAO

 

In reply to the fact that you said that vtec is not preferable to non vtec, you should know (If you don't already) that: 1 hp= TORQUE(lbs/pi.) x RPM/5252. It all begin with torque, in your engine, torque depends of volumetric efficiency, for example, the more you can fill your cylinders at 5000 RPM, the more torque you're gonna get at 5000 RPM resulting in more horsepower at 5000 RPM. The higher you can maintain V.E., the more power you're gonna get from you're engine. Volumetri efficiency depends of a lot of things, but at high rpm the inevitable is the valvetrain weight, the most penalized is the OHV engine because of the pushrod, lifter, and all this GM crap that become parisitic weight at high RPM. If you got an engine with 1lbs/pi. of torque all the ways accross the rev range from 0 to 11000 RPM, you'l end up with 1 hp@5252 RPM and 2hp@10504 RPM (3hp@15756RPM).In other words, it's torque per seconds. The Best way to make power is RPM(But you're always need torque). Theorically, the more your engine revs, the more power it makes from it's displacement, but depending on the engine configuration(OHV, SOHC, DOHC), OHV engine tends to have an unusualy high low rpm V.E. but usually lose V.E. dramasticly very soon in the revs range; SOHC engine are more linear and begin to lose V.E. around 5000-6000RPM; DOHC engine are very linear and begins to lose V.E. a little higher than SOHC engines and also got a slightly better V.E. than SOHC because of the seperate camshaft that permit some ignition timing and valve timing tuning. If your Cavalier have the 2.2L OHV, it's crap, i've owned a 1995 Pontiac Sunfire not GT with the OHV engine in it at 127000km, the automatic transmission gave out 4 monts later at 141000km, 750$ and a used V6 3.1 or 2.8 auto trans later, the car was running well but gear ratio were unusually long, 2 monts later,(158000km) this ******* crappy GM engine gave out like a tramp, with the new trans not shifting higher than 5250 RPM, i espected the engine to last a little longer than that. If you got the 2.4L DOHC, you're in better condition, don't expect this engine to have honda-like reliability, but you can expect good performance from it (with the turbo you stated earlier) but allways remember that a DOHC 2.4L(sunfire GT) is smoked out by a stock Civic SIR. You're best alternative is the ECOTEC 2.2L DOHC.There is a lot of power to expect from this engine because it comes from SAAB and it's a good turbo-nitrous beast(reliability is not like a honda).For the VTEC/not VTEC question:
*A stock non-VTEC engine is no better than a VTEC engine.
*If you take a non-VTEC and drop stage 3 cams in it, it won't idle
*VTEC Cams will always idle because it's got a lobe for it.
*VTEC trans work best with high rev engines (availibility is not a problem)
*Non-VTEC high rev engine will need a new transmission that probably dosen't exist $$$$$$$
*The sound of VTEC when it kicks in till red is priceless
*My grandma could drive an S2000 at 3000RPM, but i would never let my grandma drive a Corvette at 3000RPM, THIS IS DRIVABILITY.
*Another thing is tractability, for the same power of 500hp, a turbo non-VTEC engine that rev at 7000RPM will be a pain in the *** compare to a 10000RPM VTEC engine because when you drop the clutch at lauch, much more torque will be involve and controlling spinning will be more difficult.THIS IS DRIVABILITY

There is no replacement for displacement, but there is no replacement for honda-like V.E., have you ever heard of another company that make a 185hp 1.6L DOHC VTEC, 200hp 1.8L DOHC VTEC, 240hp V6 VTEC, 260-270-290hp V6 VTEC. Go to GM and ask them to build you a 240hp-162lbs/pi. DOHC(S2000), you'll make them laugh. I'm tired of these guys in golf VR6 who's proud of Volkswagen when smoking a SIR , let me finish my project involving a build J32A2 V6 (270hp-232lbs/pi stock), 2 turbo, intercooler, lots of nitrous and EG civic hatchback. Better get prepared to get rip you Volkswagen sucker. I don't need a V6 to smoke a souped up VR6, but they don't seem to understand honda superiority very well. I'm aiming the 600-700 hp and a additional 150-200 with nitrous on. I've heard about some 1250hp 3.0L NSX so my goals are very possible. Honda VTEC Kick ***.

 

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*A stock non-VTEC engine is no better than a VTEC engine.
*If you take a non-VTEC and drop stage 3 cams in it, it won't idle
*VTEC Cams will always idle because it's got a lobe for it.
*VTEC trans work best with high rev engines (availibility is not a problem)
*Non-VTEC high rev engine will need a new transmission that probably dosen't exist $$$$$$$
*The sound of VTEC when it kicks in till red is priceless
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#1 - Yeah, no one said it was
#2 - for the love of god, this has been confirmed at least four hundred times now. Read the posts in the threads damn it.
#3 No ****? I thought vtec was to feed the fish in the trunk? vtec is nothing but a lobe for idle
#4 There is no such thing as a VTEC trans. There were simply the transmissions used on the honda engines that had vtec technology.
#5 ugh, you can't just get a B18C1 or B16 tranny?
#6 yeah, cause sound now is so important.

Glad to see another post that didn't contribute at all

 

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vtec is nothing but a lobe for idle
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Again I say your description of VTEC is over-simplified and misses the point, completey
There is more to VTEC (in and of itself) than just the availiblity of a low lift cam to allow ideling and low rpm operation.
Is is the versatility of having VARIABLE cam profiles.
And the options it gives engine designers and "tuners", be they Honda engineers, or some HT kid who wants to hop up his Integra.
You CANNOT say all the low cam does is to allow a high lift cam engine to idle. It is NOT that simple.
You are being too narrow in your description and in you understanding how the system actually works.
Just my.02 cents

 

Yes variable valve timing has the potential to be more than just a profile for idle/streeting, and a profile for high end powerband.

At some point there may be electronically controlled valve timing, instead of cam shaft driven. Which could be altered on the fly by the ECU, based on throttle position, air pressure, rpm, temp, etc.

But at this case in time, with honda production engines, that is its purpose. A powerband is roughly 2k rpm. In terms of pure performance you never want to be out of the powerband. Until you have a cam profile that is designed for the first half of the powerband, then a second for the second half of the powerband, it is basicly a street profile and a performance profile.

 

ok thanks guys, now that i have learned a lot about the detailed workings of vtec (and how gay my cavaliers engine is even though i already know) i've changed my topic to running vtec with a race-built motor

 

Why did you change your topic to a similarly backwards one? First you were trying to argue against VTEC's main advantage (streetability) in a street motor. Now you are trying to argue for streetability in a race motor?

 

because i can't see enough to say why non-vtec is better. if non-vtec was that much better... no one would use vtec.

 

Yeah, you still have it all backwards.

Looking JUST at vtec, just on a race motor, it is unnecessary. It adds unnecessary rotational mass and more things to go wrong.

On a street motor, it can make a huge difference in being able to daily drive it.

You are asking the wrong group of people. The TECH forum is mostly guys building up their STREET cars.