OK, I'm not trying to be a jerk or anything, I just don't want to confuse people. EVO MIVEC does NOT have "profiles". Profiles would indicate that there two or more cam lobes that are being switched. (Rally Art MIVEC, VTEC..) EVOs do not do this in any way shape or form. EVOs have one profile.

Picture this: on a regular older car(no MIVEC,VVT,VTEC or anything. There is one set of lobes(profile) and the cam is bolted to the cam gear securely.(no movement between the two) Now on a MIVEC cam you have that same cam with one profile. Now put this in the motor and rotate the crankshaft which in turn rotates the timing belt and cam gear. Now, all of those things are mechanically rotating together with no way of rotating differently. a mivec cam, however, is allowed to twist on the cam gear(not freespin, just a specified amount of degrees of rotation. That is what the numbers in the table represent. (degrees of cam rotation in relation to the cam gear) Why did Mitsu decide to have the numbers spread apart? Your guess is as good as mine on that one. Maybe it does not need to be that smooth, so they didn't care to put in more scaling.

I hope this all makes sense. And as you can hopefully see the two MIVEC systems are completely different and unrelated. You could theoretically have both systems on the same car and they are both called MIVEC, but do two distinct things. I personally think that they couldn't find a cool sounding acronym, so they recycled the one they had.

 

Nice, Thanks for the info. I didn't know if anyone wanted to even try to explain it to me which is why I never asked in the first place.

 

ahh so much to learn.

 

Ok first of all I'm not trying to be a jerk either. You are focusing on one word "profile" which you are using synonymously with "lobe". Your thinking since it has 1 lobe it can't have multiple profiles. The Evo MIVEC implementation enables the single lobe cam to operate as if it had multiple profiles. I hate quoting myself but I think you missed the word "essentially".

Right, the cams your describing have a single profile. The engine your describing does not have variable cam timing or MIVEC.

The MIVEC cams change characteristics as you advance or retard them. This essentially changes the profile of the cam. Re-Read my original post, it's worded very carefully. Sorry you got hung there.

Right and this is how it is able to change it's characteristics.

Right, And my post discusses what characteristics the cams have when they are in different positions.

Yes it makes perfect sense. Your very wrong about the different MIVEC systems being unrelated. The reason why they call the implementation MIVEC is because it does what all their other MIVEC implementations do. MIVEC "essentially allows the car to operate as if it had multiple cam profiles" I hope this helps you understand.

 

Lift cant change , the timing can (on the IX's).

 

I have had several reputable sources say that the Evo MIVEC does not control lift. In fact the Evo MIVEC system appears to be nothing more than an on the fly adjustable cam gear. Of course if I was gonig to design cams for a vehicle that had a system like this I would design the cams to take advantage of what capabilities the system has.

However, I tune cars, I dont design cams. Let's keep in mind this is a tuning discussion about MIVEC. I want to know how the different values affect the engine and how to maximize performance for a chosen set of goals.. Mostly I'm tired of people saying "it's nothing like other mivec or vtec or other VVT systems" - This is not true, although the method is different the effect and intent is similar.

A few people like JohnBradley and others have taken the lead in figuring out how all of this works (Thanks millions btw). And through testing his examples and my own testing I've learned a little more about about how to tune a system with VVT. Again, whatever method they use to change between a econo / low rpm cam to a is performance cam is not as relevant as what the different profiles do and developing a strategy to take advantage of the design.

Removed EXERPT FROM IMPORT TUNER MAG / HKS camshafts for IX's, they are incorrect.

http://www.importtuner.com/tech/0711...aft/index.html

 

It's not physically changing the lift of the cam, it just makes the max lift happen sooner or later, depending on your mivec map. Does that makes sense?

Let's say the intake cam has a max lift of 10.6 (i'm pulling this out of my ***). This is with the lobe fully upright. What Mivec is doing is changing when that max lift is happening, either sooner or later, depending on what is in the mivec table.

 

What would you say problems are? please explain..

 

Specific values? I thought the values range from -1.2 to 28.8 ? I


MR.EVOIX- So by saying "low lift" and "high lift", your saying that the cams' lift will actually vary due to Mivec? How is that even possible? Mivec can't move the cam, it can only rotate it. For example, the Cosworths are a 11.0mm lift, the valves will only lift 11.0mm, no more, no less. Correct me if I'm wrong.

My thought is, that with more advance, the cam allows more air/fuel mixture in the combustion chamber before the valves seal, and the combustion occurs.. ? That makes more sense to me.

MOJO RISING- There is no way that Mivec can affect ignition timing, correct? The cam gear teeth are not being advanced, its the cam itself being rotated. So its impossible for ignition timing to be affected in such a way..

 

another thing. The lift (11.0mm on Cosworths) cannot be altered by Mivec. However, the duration at which the valve stays open, is constantly changed by Mivec.

 

Ya, so its lengthening/shortening the cam duration specs. right?

 

oh, and FYI.. I will be getting my hands on Mitsubishi's ECU program very soon. But ShHHHHHHHHH lol

 

He means the specific values in the stock Mivec map



This can be good or bad depending on when.

Mivec works like any adjustable cam gear does, it just does it on the fly. Do not confuse cam timing and ignition timing.

You are changing the valve opening/closing event.

 

edited posts

 

so. Could I shut off Mivec? lol. like by inputting -1.2* everywhere? I would like to see how the car performs. Would it be like an VIII?

I want to try and shut it off by about 5000rpms and see how that works. Thats where I am having a hard time dialing it in for my setup.

Anything less than the max before 5000rpms, then my load starts to drop. I have seen it drop, then build again with 28.2*, then drop again w/ 24.0*

And Bryan, I never have confused Mivec timing w/ ignition timing..