VTec Technology

I know this may be a a topic that has been posted before but anyways...

I have a 98' accord V6 Vtec SOHC engine.

My friend is trying to argue with me and says I don't have a complete vtec engine because I only have a SOHC and not a DOHC. He believes that for it to me a true Vtec it has to be a DOHC because the cams switch when the vtec kicks in. Now I know what VTEC means and I explained it to him.

Tell me if I am right or correct me if I'm wrong. In a SOHC since there is only one cam it is a high end cam. That is why the vtec boost only kicks in when the engine is at a high RPM. With a DOHC the vtec will switch from the low end cam to the high end cam.

The main thing is though. Is help me prove to my idiotic friend that it is a vtec. My friend is not convinced that I have a Vtec controlled engine

Trust me you do, I can feel the deference in my car even though i have SOHC V-Tec and I also have shorter gears so i have yet to reach my top speed that my LX did but I can tell its a bit quicker. SOHC V-Tec really exists but its not much like my car it only gave me an aditional 15hp compared to my LX Accord.

iirc, sohc vtec on the 4 bangers is only there to improve gas mileage, not performance.

just something i read somewhere, not sure that its true.



justin.

Well if its not there for performance then why did my HP go up and my gas mileage go down until I switched to a the mid level unleaded, and why do i have shorter gearing too. Should be the same with SkyyDragRx's Accord cause he has 200hp but the DOHC only has 200hp too whats up with that.

Quote:

Tell me if I am right or correct me if I'm wrong. In a SOHC since there is only one cam it is a high end cam. That is why the vtec boost only kicks in when the engine is at a high RPM. With a DOHC the vtec will switch from the low end cam to the high end cam.

umm...ya. i think ur a bit confused.

SOHC means Single Over Head Cam, meaning the intake and exhaust valves are controlled by a single cam. it controls both set of valves opening and closing.

DOHC means Dual Over Head Cam, meaning each set of valves has it own cam for opening and closing. being each set of valves has its own cam, the cams profiles can be tuned for better efficency, thus producing more power then a SOHC engine.

weather ur engine has a "high end" cam or a "low end" cam is irrelevant here. as i said above, the SOHC/DOHC means nothing in regards to the v-tec "boost"

wow... gross concept error...

all it does is vary the time the intake and exhaust cams open/close. ideally, when your piston goes down, intake opens, sucking exhaust into the cylinder. the second your cylinder goes up, exhaust opens. now imagine 7,000 rpm. if is opened just as it was going down, the air takes milliseconds to start moving into the cylinder.

When you increase the rpm, however, this configuration for the camshaft does not work well. If the engine is running at 4,000 rpm, the valves are opening and closing 2,000 times every minute, or thirty to fourty times every second. When the intake valve opens right at the top of the intake stroke, it turns out that the piston has a lot of trouble getting the air moving into the cylinder in the short time available (a fraction of a second). Therefore, at higher rpm ranges you want the intake valve to open prior to the intake stroke -- actually back in the exhaust stroke -- so that by the time the piston starts moving downward in the intake stroke, the valve is open and air moves freely into the cylinder during the entire intake stroke.

Vtec, or Variable Valve Timing and Lift Electronic Control, varies the time the valves open and close based on rpm band. weather it's varyin 2 cam or 4, it's still a vtec.

so you have:
VTEC - Variable valve Timing and lift Electronic Control. At low RPM, a VTEC engine uses a normal cam profile to retain a smooth idle, good fuel economy, and good low-end power delivery. The VTEC mechanism engages a high-lift, long-duration "race" cam profile at a set RPM value (i.e., ~5500RPM on the B16A) to increase high-end power delivery.

i-VTEC - This system does not really conform to the "DOHC i-VTEC" nomenclature, as Honda would like us to believe. It actually should be called "i-VTEC-E," because it uses a VTEC-E mechanism rather than a standard VTEC mechanism. At low RPM, the VTEC-E system effectively forces the engine to operate as a 12-valve engine - one of the intake valves does not open fully, thus decreasing fuel consumption. At 2200RPM, the VTEC-E system engages the 2nd intake valve, effectively resuming operation as a normal 16-valve engine. There are no high-RPM performance cam profiles; this engine is tuned to balance fuel economy and power, rather than provide pure performance. On the intake cam, there is the VTC mechanism which basically is an automatic self-adjusting cam gear used to continuously optimize the valve overlap for all RPM ranges. This being a VTEC-E system - and not a true DOHC VTEC system - is the reason the K20A3 redlines at a measly 6800RPM, while the K20A2 is able to rev all the way to 7900RPM.

VTEC - Variable valve Timing and lift Electronic Control. At low RPM, a VTEC engine uses a normal cam profile to retain a smooth idle, good fuel economy, and good low-end power delivery. The VTEC mechanism engages a high-lift, long-duration "race" cam profile at a set RPM value (i.e., ~5500RPM on the B16A engine) to increase high-end power delivery.

VTEC-E - Variable valve Timing and lift Electronic Control for Efficiency. This system isn't really VTEC as we know it. At low RPM, the VTEC-E mechanism effectively forces the engine to operate as a 12-valve engine - one of the intake valves does not open fully, thus decreasing fuel consumption. At a set RPM value (i.e., ~2500RPM in the D16Y5), the VTEC-E mechanism engages the 2nd intake valve, effectively resuming operation as a normal 16-valve engine. Note: in a VTEC-E engine, there are no high-RPM performance cam profiles; this engine is supposed to be tuned for fuel economy.

justin, you're talking about the K20A3 engine: This system does not really conform to the "DOHC i-VTEC" nomenclature, as Honda would like us to believe. it should be called "i-VTEC-E," because it uses a VTEC-E mechanism rather than a standard VTEC mechanism. At low RPM, the VTEC-E system effectively forces the engine to operate as a 12-valve engine - one of the intake valves does not open fully, thus decreasing fuel consumption. At 2200RPM, the VTEC-E system engages the 2nd intake valve, effectively resuming operation as a normal 16-valve engine. There are no high-RPM performance cam profiles; this engine is tuned to balance fuel economy and power, rather than provide pure performance. On the intake cam, there is the VTC mechanism which basically is an automatic self-adjusting cam gear used to continuously optimize the valve overlap for all RPM ranges. This being a VTEC-E system - and not a true DOHC VTEC system - is the reason the K20A3 redlines at a measly 6800RPM, while the K20A2 is able to rev all the way to 7900RPM.

Damn thats a long post...

I feel like eating rice now...

^^^

Wow that is alot to learn in technical terms. i'm still blown away on how someone can explain that in such detail.

alienyoungjr wrote:

Wow that is alot to learn in technical terms. i'm still blown away on how someone can explain that in such detail.

I'm blown away by the fact ADDICTED2ICELED has that much free time on his hands.

Most of that post was repeatative. I read the same stuff over and over. Nothing about my SOHC. My friend still doesn't believe me that I have a real Vtec. He is still convenced I am missing the right cams. I explained to him if I didn't have the right cams then my car wouldn't run. He doesn't understand and probably never will

i'm sorry you feel that way... i kept repeating it because i know some people can't get the point out of what's being said. would you like it in spanish?

here:
"usted tiene tan: VTEC - Sincronización variable de la válvula y control electrónico de la elevación. En la RPM baja, un motor de VTEC utiliza un perfil normal de la leva para conservar una economía de combustible ociosa, buena lisa, y una buena entrega de energía del bajo-extremo. El mecanismo de VTEC contrata un high-lift, "race" de la largo-duracio'n; perfil de la leva en un valor del sistema RPM (es decir, ~5500RPM en el B16A) para aumentar entrega de energía high-end."

"or how bout french?
ainsi vous avez : VTEC - Synchronisation variable de valve et commande électronique d'ascenseur. Au bas T/MN, un moteur de VTEC emploie un profil normal de came pour maintenir une économie de carburant à vide et bonne douce, et une bonne fourniture de courant d'bas-extrémité. Le mécanisme de VTEC engage un hypersustentateur, "race" de long-durée ; profil de came à une valeur de l'ensemble T/MN (c.-à-d., ~5500RPM sur le B16A) pour augmenter la fourniture de courant à extrémité élevé."


"or in chinese:
如此您有: VTEC - 易变的阀门时间和推力电子控制。在低RPM, VTEC 引擎使用正常凸轮外形保留光滑的无所事事, 好燃料经济, 和好低结束功率传输。VTEC 机制参与高举, 长期间"race" 凸轮外形在集合RPM 价值(即, ~5500RPM 在B16.A) 增加高端功率传输。"

or how bout just in english as i said it the first time:

"Vtec, or Variable Valve Timing and Lift Electronic Control, varies the time the valves open and close based on rpm band. weather it's varyin 2 cam or 4, it's still a vtec.
so you have:VTEC - Variable valve Timing and lift Electronic Control. At low RPM, a VTEC engine uses a normal cam profile to retain a smooth idle, good fuel economy, and good low-end power delivery. The VTEC mechanism engages a high-lift, long-duration "race" cam profile at a set RPM value (i.e., ~5500RPM on the B16A) to increase high-end power delivery. "

anyway, first you ask for help, then you pay so much attention to the repetativeness of my post that you neglect to even read what was said, just so you can critque my post and say it was repetative. it seems the only reason "you read stuff over and over again" was because you seem to struggle a bit comprehending words. so just help me out here... was it the first part in bold where it says "wether it's varying 2 cam or 4, it's still a vtec" or the "so you have: VTEC" that you didn't get?

well.. just remember, there's two rules in life.

Vtec is Vtec no matter if u have SOHC or 20 over head cams. tell ur friend hes ******* and needs to read up on what he is talking about.

also, what do u wanna know about ur SOHC?

if you really want to learn listen to addicted. he obviously knows what he is talking about. i just want to clear a few things up, first of all honda copied the idea of electronitcally varied valve timing from Mitsubishi. second, vtec doesnt add any boost, turbos and superchargers add boost. boost isnt created by advancing or retarding the timing. when you get down to it, there are 2 reasons to buy a honda

1) you want a cheap, reliable car, that gets great mileage.
2) you're a total ******* that thinks they can actually be fast.

there is a certain law with all cars. the dream car is fast, cheap, and reliable.
realistically, you can pick two of those. cheap and reliable but slow. cheap and fast, but unreliable. fast and reliable, but expensive. there is no way to get a cheap car thats fast and reliable.

go ahead, try to disagree with any of my statements.
also, you may have 200 hp, but you only have enough torque to tighten lug nuts.
i have about 300 hp, and nearly the same ft/lbs of torque.

Your company is going out of business...

Nah nah nah nah...
nah nah nah nah...
hey hey hey...
GOOD BYE!

2) you're a total ******* that thinks they can actually be fast.

Actually...thats just a ******* statement...

DSM Loki wrote:

have about 300 hp, and nearly the same ft/lbs of torque

Oznium Gallery wrote:

1990 Plymouth Lazer: No Photos

I wanna see



justin.

I know some hondas that will walk on ur laser, i dont care what ur hp is.
What do you run in the 1/4? Hondas can be very fast, you just need to get ur
head out of ur ass and realize that a civic can also run 300 hp.

Don't Vtec stand for "very tall engine compartment"

i wanna see the laser too..and a couple timeslips

josh9015 wrote:

Don't Vtec stand for "very tall engine compartment"

hey thats a pretty good one but no it doesn't stnd for that, but nice try.

I was just joshin you. I used to have a 98 vtec accord. It was cool.

josh9015 wrote:

I was just joshin you. I used to have a 98 vtec accord. It was cool.

i knwo you were joshin me but it was funny. What happened to your accord? Mine is a I4 Vtec.

yes we know, any modified car CAN be made fast. (*shrugs)


I think his point is many cars are MUCH easier and cheaper
to modify then a n/a FWD 4 banger. A 4g63 making 450+hp
on totally stock internals, no problem. A honda motor making
that on stock block, haha good luck

Theres a FEW swapped turbo hatches (that weigh about 2 pounds)
that are quick around here. They have spent WAY too much
money to not break outta 13's. A peak horsepower number doesn't
mean much overall, but getting the power to the ground does
(read- FWD is a joke). Different strokes for different folks I guess.
Saying you are a ******* for building a honda up is kinda ignorant,
but saying its a good choice for a fast street car in 1/4 mile
performance is laughable.

man, addicted's post fried my brain. good info.

maybe i should race this laser with my 2g gsx...and how did honda steal vtec from Mitsu...i've never heard of eclipses or talons or anything having vtec?? as for a 4g63 handling alot of power..unless you have a 6 bolt block your not gonna CRANKWALK!!! Honda engines can handle way more power...some here that run in the low 12's with a D Series...and 1 that runs a 10.5.

i'd like to see a dynograph of this lasers 300 hp too!

enviousmonte wrote:

maybe i should race this laser with my 2g gsx...and how did honda steal vtec from Mitsu...i've never heard of eclipses or talons or anything having vtec??

You know mitsu made more cars then just the eclipse correct? There "vtec" equalivalant (mivec) was introduced around 92 and used in the FTO, mirage (colt) , and lancer in japan. I don't think it was before honda but frankly couldn't care less who was first. ZETEC was actually before vtec.

enviousmonte wrote:

Honda engines can handle way more power...some here that run in the low 12's with a D Series...and 1 that runs a 10.5.

Is this a joke???

No they don't, in fact its not even close.
Stock- Not close, laughable
Built up- still not close.
How many hondas have run high 10's on a totally stock block, how many have made 400-500 hp on an untouched/unmodified block? how many "street" non tube chasis hondas are running 8's, 9's 10's. There not even close. A low 12? Lets see how much artic tsi had to put in his car talon for a low 12's

Quote:

I ran 12.39 @ 112.66 with my 14b (STOCK turbo) @ 18psi on 93 octane pump during the 2004 Forced Performance Shootout. No port work of any kind, stock bottom(pistons & all), stock head, stock cams, stock exhaust manny, stock intake manny, stock fuel pump(re-wire), stock 450's. go fast goodies-FMIC & BOV, downpipe & exhaust, MBC, MAF-T & 3.5 GM Maf(blow-by setup), homemade cold air intake.

http://dsmtuners.com/forums/showthread.php?t=147870&page=1&pp=25
Heres a vid of him beating up a vette, remeber its the STOCK turbo, engine, fuel,tires etc on a 2.0 liter 4 banger.
http://www.arctic-racing.com/media/videos/14bVsZO6.mpg

How much does it cost fora honda to run a low 12? Betcha more then the price of an exhaust and a boost controller. Times that by 5 and you still wouldn't hit it. With street tires (no DR/slicks), the time is almosty impossible w/ a honda. FWD sucks, trust me, I know firsthand.


Wait,,,Heres a SWEET streetdriven 10 second honda. I've never seen one that was 12seconds under and a street car. Wonder what makes this 10 second capable of this feat. Could it be the fact that, oh wait, it took an eclipse/evo (4g63) engine and its AWD drivetrain. How many eclipses have swapped in a honda motor? Is that silence I hear?

http://www.ef-honda.com/main/viewtopic.php?t=4532&postdays=0&postorder=asc&start=0

I just don't understand how having a few fast hondas in your city means they hold more power. Theres a slew of 11 second and low 12second 1g's in my city and kiggly from team rip (teamrip.com) locally runs high 9's in his 1g. Travel 100 miles south you run into this 8.7 monster on street tires.

http://www.eden.rutgers.edu/~mcharos/shepracing.wmv.

Okay, lets travel north a couple 100 miles instead. Wait, heres a DAILY driven 2g that is driven quite a ways to work everyday running high 9's making over 700 horsepower on street tires. Show me a non fullout, slicked, tube chassis ,backhalved drag 900 pound honda motor doing this and i'll eat my shoe.

low 10 run on REAL street tires
http://www.tappauto.com/images/picsvids/10.3small.wmv
707 whp pull
http://www.tappauto.com/images/picsvids/707pull.wmv

enviousmonte wrote:

i'd like to see a dynograph of this lasers 300 hp too!

Honestly, what are you expecting to see as mods?
a boost controller, exhaust, and intake maft on a 1g will get him 300+ hp at the crank quite easily. Buy a new turbo (16g,to4b etc) for 500-600 bucks he could blow that figure away.


If you want to debate thats fine, but I don't need a million post that have no fact or people that attack me but can't factually refute what i said

Dave Chapelle voice - "In Yo Face!"

wow, its been a while since i've visited this site, great to see a fellow dsmer, where are you from? i mean, TRE is local to kalamazoo here, down on rose i think. i should really log on more often, no reason to before, just a bunch of people asking how fast their whale wing will make them, and as for my mods, i'll list
hacked maf, 18psi, rewired fuel pump, exhaust, egr removed, symborkis, short shifter. and thats it. stock everything, also my car ran 13.6@107 at martin dragway. true, crankwalk an 2gs sucks, thats why i have my 6bolt, until i had an injector failure last week, had some sustained detonation, and melted the #4 piston, so its time for a new engine, evoIII 16g, 3" exhaust, mings old 2g maf is going in, walbro255, 650 injectors, safc-2, eprom ecu, fmic, hard intake pipes, greddy type s, and a few mor things. if any of you guys hear abou a nice 1gb awd, not bad on miles, let me know.\

EDIT: i was running 20psi on race gas, with potentiomiter in place of the iat sensor, car thought it was -6* when it was actually about 78.



and the 8 second monster he's talking about is john shepherd car, www.shepracing.com

word to your vtec

anybody see the twin engine talon at buchurs shootout in norwalk? it was kinda scary, and the evoII was nice, then again, so was the party at the econolodge.

right now I'm running high 16's in a STOCK D16y5 (SOHC Vtec). I'm happy with that.

My 96 supercharged GT with a Procharger was running low 12's....till I blew up the engine

The STI, WRX, Evo's etc are fast cars, from my dealings with Hondas the only way to get them into decent power gains without jeopordizing the engine is to drop a new motor in and start there............ANY car can be made fast, its just rather how much money you are willing to spend in order to make it fast

^^^ exactly... which is why I'm saving up for a polished b16....or 18