MIVEC tuning
Nov 15, 2012, 11:21 AM
#738
Maybe I didn't completely get it or remember it, but a value of 10 in the table was actually 0 advance, so that values less than that were retarding the intake cam. I just tried to scroll through this whole post, because I seem to remember a very clear diagram that mrfred or JB provided, but I couldn't find it. It could have been a different mivec thread though.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Nov 15, 2012, 11:37 AM
#739
Maybe I didn't completely get it or remember it, but a value of 10 in the table was actually 0 advance, so that values less than that were retarding the intake cam. I just tried to scroll through this whole post, because I seem to remember a very clear diagram that mrfred or JB provided, but I couldn't find it. It could have been a different mivec thread though.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Nov 15, 2012, 02:55 PM
#741
Maybe I didn't completely get it or remember it, but a value of 10 in the table was actually 0 advance, so that values less than that were retarding the intake cam. I just tried to scroll through this whole post, because I seem to remember a very clear diagram that mrfred or JB provided, but I couldn't find it. It could have been a different mivec thread though.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Definitely something about 10, being the center value, and I could just have what that means mixed up.
Logically a lot of the guys with bigger power were going to 0 in the high RPM cells and seeing improvement, which makes mechanical sense as the super high RPMs produce a different effect on VE and the higher the RPMs the slower the advance that is set actually is. So to keep it efficient they back down the advance, eventually into a slightly retarded state. At least that is what I got out of it.
Nov 15, 2012, 03:11 PM
#742
cool thread.
I tune mivec based on how much cylinder pressure I can generate while paying attention to the knock sensitivity of the engine, and the EBP as mychailo mentioned.
although I prefer to verify and validate those theories on the dyno.
I tune mivec based on how much cylinder pressure I can generate while paying attention to the knock sensitivity of the engine, and the EBP as mychailo mentioned.
although I prefer to verify and validate those theories on the dyno.
Nov 17, 2012, 10:45 PM
#743
i took and used JB's Mivec map for S2's posted in this thread. It was a little jerky at times for me so I took a more smooth and rounded approach while keeping cues in check between a few popular theories and trends. Lurching is gone though. and my pregnant half loves that!
https://www.evolutionm.net/forums/ev...questions.html
https://www.evolutionm.net/forums/ev...questions.html
Last edited by 211Ratsbud; Nov 17, 2012 at 10:54 PM.
Nov 21, 2012, 05:32 AM
#747
Good info guys.
I have since Added some changes to my Mivec map after reading what Mr Fred had just posted. Last month I have been playing with the idle cells and I also tapered the advance in the high load areas starting with the addition of adding 3250 rpm cell. I did that to help with spool and throttle response. I had experimented with starting the taper at 3000. Although it felt more snappy and responsive I was worried about to much stress to the bottom end.
I also lowered the advance at the 5500 cell in efforts to combat some knock that I was seeing.
Unforunately I haven't been able to test it since the latest change due to leaving on a short notice trip.
When I get a chance I'll try and load up the new map so you guys can see.
I was looking at one of my logs and I have noticed that timing seems to come in 250 rpms sooner than what is on the map. For example let say at 5000 rpm load cell 280 I see 4 degrees and towards It's transition to the next rpm range same call it will advance the timing 250 rpm sooner than what's on the map.
Is Mivec the same?
I have since Added some changes to my Mivec map after reading what Mr Fred had just posted. Last month I have been playing with the idle cells and I also tapered the advance in the high load areas starting with the addition of adding 3250 rpm cell. I did that to help with spool and throttle response. I had experimented with starting the taper at 3000. Although it felt more snappy and responsive I was worried about to much stress to the bottom end.
I also lowered the advance at the 5500 cell in efforts to combat some knock that I was seeing.
Unforunately I haven't been able to test it since the latest change due to leaving on a short notice trip.
When I get a chance I'll try and load up the new map so you guys can see.
I was looking at one of my logs and I have noticed that timing seems to come in 250 rpms sooner than what is on the map. For example let say at 5000 rpm load cell 280 I see 4 degrees and towards It's transition to the next rpm range same call it will advance the timing 250 rpm sooner than what's on the map.
Is Mivec the same?
well here is my new map but unfortunately i didnt have a chance to test it since i had to leave on short notice. its slightly different the my last but once i return i plan on adding a couple of things to include a DC2 split catch can setup with making the vent on the side of the VC bigger. once thats done i'll do some more logging and determine if i need to taper the advance in the 5000 and higher rpm.
211 how is JB Mivec Map doing so far?
has anyone noticed if the MIVEC transitions to the next value earlier than whats on the map?
Last edited by vmrevo9; Nov 24, 2012 at 06:07 PM.
Nov 21, 2012, 02:04 PM
#748
I haven't done any testing for the mivec as far as testing gains. I was improving parking lot lurching but I have faith in jb's map as a good base point so I probably will just tweak this once I get goin.. It lurches at less than 2500 off throttle to on transition on corners and parking lots .. No biggie 
though needs to be tailored a little.
though needs to be tailored a little.