MIVEC tuning
Newbie
Joined: Jun 2006
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From: florida
Originally Posted by Guerillah
MIVEC only retards the intake cam, not advance so going to 0 retard at redline is probably a good thing?
Found this with a search...
"The MIVEC system can alter the intake camshaft sprocket's phase angle to retard the timing of the closure of the intake valves at higher rpm. This valve event timing creates more power because of the more efficient and complete filling of the combustion chamber thanks to the intake charge's inertia effect. Meanwhile at lower rpm, the MIVEC system will retard the timing of the opening of the intake valves to decrease intake/exhaust overlap timing, helping promote more stable combustion, while reducing fuel consumption and emissions.
The Lancer Evolution’s MIVEC system uses the engine’s oil pressure to engage movement of the intake camshaft’s front sprocket. As the camshaft control signals are received from the ECM, a spool valve at the oil control valve moves the sprocket toward the advance or retard side depending on the ECM signal. As the intake camshaft’s actual and target sprocket angles meet, the oil pressure in the advance and the retard chambers is held to maintain the phase angle of the camshaft. The MIVEC system’s oil control valve is a closed loop system so that the actual and target phase angels are identical."
"The MIVEC system can alter the intake camshaft sprocket's phase angle to retard the timing of the closure of the intake valves at higher rpm. This valve event timing creates more power because of the more efficient and complete filling of the combustion chamber thanks to the intake charge's inertia effect. Meanwhile at lower rpm, the MIVEC system will retard the timing of the opening of the intake valves to decrease intake/exhaust overlap timing, helping promote more stable combustion, while reducing fuel consumption and emissions.
The Lancer Evolution’s MIVEC system uses the engine’s oil pressure to engage movement of the intake camshaft’s front sprocket. As the camshaft control signals are received from the ECM, a spool valve at the oil control valve moves the sprocket toward the advance or retard side depending on the ECM signal. As the intake camshaft’s actual and target sprocket angles meet, the oil pressure in the advance and the retard chambers is held to maintain the phase angle of the camshaft. The MIVEC system’s oil control valve is a closed loop system so that the actual and target phase angels are identical."
Newbie
Joined: Jun 2006
Posts: 87
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From: florida
Originally Posted by Guerillah
Found this with a search...
"The MIVEC system can alter the intake camshaft sprocket's phase angle to retard the timing of the closure of the intake valves at higher rpm. This valve event timing creates more power because of the more efficient and complete filling of the combustion chamber thanks to the intake charge's inertia effect. Meanwhile at lower rpm, the MIVEC system will retard the timing of the opening of the intake valves to decrease intake/exhaust overlap timing, helping promote more stable combustion, while reducing fuel consumption and emissions.
The Lancer Evolution’s MIVEC system uses the engine’s oil pressure to engage movement of the intake camshaft’s front sprocket. As the camshaft control signals are received from the ECM, a spool valve at the oil control valve moves the sprocket toward the advance or retard side depending on the ECM signal. As the intake camshaft’s actual and target sprocket angles meet, the oil pressure in the advance and the retard chambers is held to maintain the phase angle of the camshaft. The MIVEC system’s oil control valve is a closed loop system so that the actual and target phase angels are identical."
"The MIVEC system can alter the intake camshaft sprocket's phase angle to retard the timing of the closure of the intake valves at higher rpm. This valve event timing creates more power because of the more efficient and complete filling of the combustion chamber thanks to the intake charge's inertia effect. Meanwhile at lower rpm, the MIVEC system will retard the timing of the opening of the intake valves to decrease intake/exhaust overlap timing, helping promote more stable combustion, while reducing fuel consumption and emissions.
The Lancer Evolution’s MIVEC system uses the engine’s oil pressure to engage movement of the intake camshaft’s front sprocket. As the camshaft control signals are received from the ECM, a spool valve at the oil control valve moves the sprocket toward the advance or retard side depending on the ECM signal. As the intake camshaft’s actual and target sprocket angles meet, the oil pressure in the advance and the retard chambers is held to maintain the phase angle of the camshaft. The MIVEC system’s oil control valve is a closed loop system so that the actual and target phase angels are identical."
Newbie
Joined: Jun 2006
Posts: 87
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From: florida
Originally Posted by razorlab
I believe the rumor is that at 0 in the map the intake cam is actually retarded a little.
Originally Posted by razorlab
I believe the rumor is that at 0 in the map the intake cam is actually retarded a little.
Originally Posted by cbrtrx
yes i was told the same, i was told around 10 on the ecuflash was close to 0 degrees
https://www.evolutionm.net/forums/sh...7&postcount=83
https://www.evolutionm.net/forums/sh...5&postcount=99
The math has been done. These are actual engineering specs from the 2006 Mitsu Evo IX service manual. There is no guessing really. The cam gear cannot go negative on the map. Sure you can put it in, but it doesnt go further than 0* just as going over 30* on the map doesnt mean the cam gear is magically going to whatever amount over it is set at.
The factory intake cam is ground on a 130* intake centerline (at least according the the math provided by Mitsubishi). When I get a spare intake cam to measure I will have all the specs that arent normally available so we can compare.
However we can do some math and come up with some rough math:
130 intake + 110 degree exhaust (mitsu numbers are EVO 58*/EVC 18*)= 120* LSA.
For reference an VIII with any HKS would be 110 LSA with the cam gears set at 0*.
Hope this helps a little.
However we can do some math and come up with some rough math:
130 intake + 110 degree exhaust (mitsu numbers are EVO 58*/EVC 18*)= 120* LSA.
For reference an VIII with any HKS would be 110 LSA with the cam gears set at 0*.
Hope this helps a little.
Originally Posted by razorlab
So John,
Mivec set at 0 in the map means -5 cam? I suck at math so that is why I am asking.
Mivec set at 0 in the map means -5 cam? I suck at math so that is why I am asking.
Newbie
Joined: Jun 2006
Posts: 87
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From: florida
i was just told by a tuner that the cam has oil passages in it to go negitive on the cam gear and not just positive, now im not saying theres any power to be made by going even more negitive but that has just been told to me that the cam gear can go both ways
If that were true I am curious why the published cam specs wouldnt show that? Maybe it can. I wont deny its a possibility, but based on the information I have from the service manual and what I have seen in all the factory MIVEC maps would tend to me believe it cant.
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Joined: Aug 2006
Posts: 19
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From: Florida
Originally Posted by JohnBradley
MIVEC set at 0* means its retarded 9.5*cam degrees (19 crank degrees) compared to a stock VIII.
I was originally told that the cam was retarded 5* compared to an VIII. That information was not correct, and I already posted that. The quote that you have right now actually answers your question. The MIVEC table is telling you exactly when the intake valve opens BTDC. 0* on the table means the IVO 0* BTDC, which alternately means it is closing at 80* ABDC. The VIII's intake valve with a stock cam and cam gear opens 19* BTDC and closes 61* ABDC.
0* on the table means its 19* crank degrees retarded compared to an VIII. The only thing that modifies this as far as power is the Intake centerline and the resulting lobecenter. For the time being I suggest we not talk about that, until at least everyone seems to have the MIVEC table fully figured out.
0* on the table means its 19* crank degrees retarded compared to an VIII. The only thing that modifies this as far as power is the Intake centerline and the resulting lobecenter. For the time being I suggest we not talk about that, until at least everyone seems to have the MIVEC table fully figured out.
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