MIVEC vs. VTEC...wtf?
Apr 16, 2008, 05:41 AM
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MIVEC vs. VTEC...wtf?
ok i guess i've been wrong all along..but i never seriously researched it or paid attention i guess..i was under the impression mivec had 3 cam profiles and vtec 2..come to find out its the other way around!!..omg, i've been telling dudes i had 3, therefore better torque etc..i feel like a fool now..lol..anyway, somebody set me straight on the virtues of mivec over vtec in a nutshell please...why would 2 cam profiles be better than 3?..seems like it would be the other way around...or is a vvt good period- compared to engines from the '80s and such...that's my feeling- hondas, toyotas, mitsu, nissan, mini. vw, all have generally the same power (stock)in their respective class...unless you want to split hairs about 100th/seconds etc...i do know mivec has higher tq per hp rating- right??
and what is so great about ecotec? or whatever cobalts have..cobalts (spit on ground)
and what is so great about ecotec? or whatever cobalts have..cobalts (spit on ground)
Apr 16, 2008, 07:11 AM
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MIVEC on the 4G69 = 3 cam profiles. Low, Mid, High.
The transition from Low-Mid-High is so close in the 4G69, you can't really tell. The switch is based on engine speed (i.e. oil/hydraulic pressure). There is a sensor that tells the ECU to adjust timing accordingly.
Old skool VTEC = 2 cam profiles
New skool iVTEC (2 types) = 3 profiles continuously variable (camshaft advance capable between 25 and 50 degrees)....think K series motors; and 2 profiles on economy type engines
The transition from Low-Mid-High is so close in the 4G69, you can't really tell. The switch is based on engine speed (i.e. oil/hydraulic pressure). There is a sensor that tells the ECU to adjust timing accordingly.
Old skool VTEC = 2 cam profiles
New skool iVTEC (2 types) = 3 profiles continuously variable (camshaft advance capable between 25 and 50 degrees)....think K series motors; and 2 profiles on economy type engines
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biglou360 (Dec 9, 2022)
Apr 16, 2008, 08:37 AM
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more specifically (if it could be so
) the mivec cam has two intake stages and three intake lobes. stage one is below ~3600 RPM and has two lobes, one low and one mid. both open, but at different lift and duration. mitsu combined enough idle and torque between these two lobes to make a nice drivable engine at low speeds. once you exceed the requirements for mivec the rockers change to the second stage configuration and you are running off one lobe per cylinder, albeit a much larger one. this lobe is somewhere around 280 degrees, bad for idle but good for power. the rockers now push both intake valves per cylinder the same lift and duration, much greater than that of either stage one lobe.
two exhaust lobes per cylinder bring our lobe count to five per cylinder: low and mid, high, and two exhaust.
I don't know how vtec works, and won't unless I buy a vehicle with it, but my car is faster than more than a few mivec and vtec vehicles. all engine designs (in terms of GOOD design I suppose
) have their pluses and minuses. honda makes very reliable high HP engines. mitsu chose a little more torque (good for the track/rally heritage I would imagine) instead of looking for all power
if you want to fly down the 1/4 I'd bet you'd be better off with a high HP honda engine than ours (at least on our chassis as it is )
) the mivec cam has two intake stages and three intake lobes. stage one is below ~3600 RPM and has two lobes, one low and one mid. both open, but at different lift and duration. mitsu combined enough idle and torque between these two lobes to make a nice drivable engine at low speeds. once you exceed the requirements for mivec the rockers change to the second stage configuration and you are running off one lobe per cylinder, albeit a much larger one. this lobe is somewhere around 280 degrees, bad for idle but good for power. the rockers now push both intake valves per cylinder the same lift and duration, much greater than that of either stage one lobe. two exhaust lobes per cylinder bring our lobe count to five per cylinder: low and mid, high, and two exhaust.
I don't know how vtec works, and won't unless I buy a vehicle with it, but my car is faster than more than a few mivec and vtec vehicles. all engine designs (in terms of GOOD design I suppose
) have their pluses and minuses. honda makes very reliable high HP engines. mitsu chose a little more torque (good for the track/rally heritage I would imagine) instead of looking for all power if you want to fly down the 1/4 I'd bet you'd be better off with a high HP honda engine than ours (at least on our chassis as it is )
Apr 16, 2008, 09:18 AM
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cool thnx..then i should have 3 profiles since mine's an '05...i assume the 05 have the 4g69's..there is a vid on youtube explaining mivec vs. vtec but its in JAPANESE...but you can read the graphs.
Apr 16, 2008, 11:35 AM
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yeah, BMW's dual vannos is muy bueno to say the least. Z3 coupe FTW cool looks and mean as engine.
although the "legendary" vtech is antiquated at this point I'd agree: honda makes a solid engine and there scientists developing new technologies are no slouches. i-vtec was a sound response to mivec for sure
cool looks and mean as engine.although the "legendary" vtech is antiquated at this point I'd agree: honda makes a solid engine and there scientists developing new technologies are no slouches. i-vtec was a sound response to mivec for sure
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Apr 16, 2008, 02:24 PM
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more specifically (if it could be so ) the mivec cam has two intake stages and three intake lobes. stage one is below ~3600 RPM and has two lobes, one low and one mid. both open, but at different lift and duration. mitsu combined enough idle and torque between these two lobes to make a nice drivable engine at low speeds. once you exceed the requirements for mivec the rockers change to the second stage configuration and you are running off one lobe per cylinder, albeit a much larger one. this lobe is somewhere around 280 degrees, bad for idle but good for power. the rockers now push both intake valves per cylinder the same lift and duration, much greater than that of either stage one lobe.
two exhaust lobes per cylinder bring our lobe count to five per cylinder: low and mid, high, and two exhaust.
I don't know how vtec works, and won't unless I buy a vehicle with it, but my car is faster than more than a few mivec and vtec vehicles. all engine designs (in terms of GOOD design I suppose ) have their pluses and minuses. honda makes very reliable high HP engines. mitsu chose a little more torque (good for the track/rally heritage I would imagine) instead of looking for all power if you want to fly down the 1/4 I'd bet you'd be better off with a high HP honda engine than ours (at least on our chassis as it is )
) the mivec cam has two intake stages and three intake lobes. stage one is below ~3600 RPM and has two lobes, one low and one mid. both open, but at different lift and duration. mitsu combined enough idle and torque between these two lobes to make a nice drivable engine at low speeds. once you exceed the requirements for mivec the rockers change to the second stage configuration and you are running off one lobe per cylinder, albeit a much larger one. this lobe is somewhere around 280 degrees, bad for idle but good for power. the rockers now push both intake valves per cylinder the same lift and duration, much greater than that of either stage one lobe. two exhaust lobes per cylinder bring our lobe count to five per cylinder: low and mid, high, and two exhaust.
I don't know how vtec works, and won't unless I buy a vehicle with it, but my car is faster than more than a few mivec and vtec vehicles. all engine designs (in terms of GOOD design I suppose
) have their pluses and minuses. honda makes very reliable high HP engines. mitsu chose a little more torque (good for the track/rally heritage I would imagine) instead of looking for all power if you want to fly down the 1/4 I'd bet you'd be better off with a high HP honda engine than ours (at least on our chassis as it is )Which is why they are so good in Auto X
Also, our g69 was made mostly for economy, so for performance, u will have to do it on your own, which is the reason the car responds so well to basic mods, especially air flow, and leaning the car a bit. The most perfect way to describe it is that you can survive many spills and driver error on our engine, whereas K20s, 2zzs and in some cases b series are weaker, more fragile, when it comes to driver error( not abuse, since its so damn finicky), they are made for spirited experienced driving, in ours, my wife can shift from 3rd to 2nd and still the engine will be good, at least with minimum damage
Apr 16, 2008, 03:27 PM
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ive taking my lancer to autocross and it was horrible at it, way to much torque, i just kept spinging around those cones. it was like the front end was on an ice skating rink
Last edited by Kurt; Apr 17, 2008 at 10:30 AM.
Apr 16, 2008, 07:06 PM
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MIVEC on the 4G69 = 3 cam profiles. Low, Mid, High.
The transition from Low-Mid-High is so close in the 4G69, you can't really tell. The switch is based on engine speed (i.e. oil/hydraulic pressure). There is a sensor that tells the ECU to adjust timing accordingly.
Old skool VTEC = 2 cam profiles
New skool iVTEC (2 types) = 3 profiles continuously variable (camshaft advance capable between 25 and 50 degrees)....think K series motors; and 2 profiles on economy type engines
The transition from Low-Mid-High is so close in the 4G69, you can't really tell. The switch is based on engine speed (i.e. oil/hydraulic pressure). There is a sensor that tells the ECU to adjust timing accordingly.
Old skool VTEC = 2 cam profiles
New skool iVTEC (2 types) = 3 profiles continuously variable (camshaft advance capable between 25 and 50 degrees)....think K series motors; and 2 profiles on economy type engines
I'm a lurker here reading up because I'm purchasing a lancer here soon, just doing my research...
anyway just wanted to correct you since I'm coming from an extensive honda background.
All forms of old Vtec (starting in 1989) from the NSX to the B16 to the S2000 have 3 cam profiles. It works exactly like the pre-04 MIVEC. The only exception is the civic Vtec-E (economy 1.5l) which is a two lobe system.
On the newer I-Vtec they use a 3 lobe system as well, but with variable cam timing as well on the intake cam gear(just like newer MIVEC, but MIVEC has in on the exhaust also right?). It seems that Mitsubishi is just following in hondas footsteps, about 3 years behind. But in reality Honda is following Ferrari.
There are a few exceptions of I-Vtec that use 2 cam profiles like the accord and other economy motors.
Honda is almost ready to put into production the A-Vtec, which uses a CONTINUOUSLY variable cam profile. So no more "hitting vtec", because vtec would be changing continuously. Ferrari already has this but from what I understand they use a sliding camshaft with a sloped cam profile so it slides down and the slope gets larger pushing the valve open more. Hondas new A-Vtec is a more effiicient system, that uses an intermediate rocker system so the machining and friction losses from a progressive sliding cam are avoided.
The intermediate rocker is number 10 in this photo, and it rotates as RPM increases, which makes it not a 2 or 3 cam lobe system, but an infinite cam lobe system.
Last edited by bambbrose; Apr 16, 2008 at 08:04 PM.
Apr 17, 2008, 04:21 AM
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I'm a lurker here reading up because I'm purchasing a lancer here soon, just doing my research...
anyway just wanted to correct you since I'm coming from an extensive honda background.
All forms of old Vtec (starting in 1989) from the NSX to the B16 to the S2000 have 3 cam profiles. It works exactly like the pre-04 MIVEC. The only exception is the civic Vtec-E (economy 1.5l) which is a two lobe system.
On the newer I-Vtec they use a 3 lobe system as well, but with variable cam timing as well on the intake cam gear(just like newer MIVEC, but MIVEC has in on the exhaust also right?). It seems that Mitsubishi is just following in hondas footsteps, about 3 years behind. But in reality Honda is following Ferrari.
There are a few exceptions of I-Vtec that use 2 cam profiles like the accord and other economy motors.
Honda is almost ready to put into production the A-Vtec, which uses a CONTINUOUSLY variable cam profile. So no more "hitting vtec", because vtec would be changing continuously. Ferrari already has this but from what I understand they use a sliding camshaft with a sloped cam profile so it slides down and the slope gets larger pushing the valve open more. Hondas new A-Vtec is a more effiicient system, that uses an intermediate rocker system so the machining and friction losses from a progressive sliding cam are avoided.
The intermediate rocker is number 10 in this photo, and it rotates as RPM increases, which makes it not a 2 or 3 cam lobe system, but an infinite cam lobe system.
anyway just wanted to correct you since I'm coming from an extensive honda background.
All forms of old Vtec (starting in 1989) from the NSX to the B16 to the S2000 have 3 cam profiles. It works exactly like the pre-04 MIVEC. The only exception is the civic Vtec-E (economy 1.5l) which is a two lobe system.
On the newer I-Vtec they use a 3 lobe system as well, but with variable cam timing as well on the intake cam gear(just like newer MIVEC, but MIVEC has in on the exhaust also right?). It seems that Mitsubishi is just following in hondas footsteps, about 3 years behind. But in reality Honda is following Ferrari.
There are a few exceptions of I-Vtec that use 2 cam profiles like the accord and other economy motors.
Honda is almost ready to put into production the A-Vtec, which uses a CONTINUOUSLY variable cam profile. So no more "hitting vtec", because vtec would be changing continuously. Ferrari already has this but from what I understand they use a sliding camshaft with a sloped cam profile so it slides down and the slope gets larger pushing the valve open more. Hondas new A-Vtec is a more effiicient system, that uses an intermediate rocker system so the machining and friction losses from a progressive sliding cam are avoided.
The intermediate rocker is number 10 in this photo, and it rotates as RPM increases, which makes it not a 2 or 3 cam lobe system, but an infinite cam lobe system.
whew that's a lot to take in you lost me...i like honda's switchover point..too bad they'll lose it with a continous cvtt or whatever...i don't want my car to be too damn advanced...i'm over 40 and use to own muscle cars..been driving 30yrs....that's why i didn't buy the new Lancer GTS..i drove it and it was too smooth and tame with its superior this and that..love my older RA..it has GUTS