MIVEC tuning
Jun 16, 2008, 06:13 PM
#467
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Recently I reduced mivec from 28.8* to 24* from load 200 onwards from 3000 rpm. I found the car to run the same boost, same timing but the car ran 0.5 lambda leaner?
Can someone explain what is going on here?
I guess retarding mivec here is making more power/torque?
Would I benefit using 24* from a lower load, for example, from 160 load as opposed to 28.8*?
A bit confused...
Can someone explain what is going on here?
I guess retarding mivec here is making more power/torque?
Would I benefit using 24* from a lower load, for example, from 160 load as opposed to 28.8*?
A bit confused...
are you really using lambda to monitor your Afr? I hope not. But yes, Mivec will effect the AFR and boost. I would use 28.8* until your boost peaks(3000-3500rpms/above 200load), then maybe taper off? I cant really say, since I dont know your mods/specs.. Mivec takes alot of time to properly test and develop a solid map.
Jun 16, 2008, 06:15 PM
#469
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pull up your maps you want to shoot. then hit the "print screen" button to the right of the backspace button. Then open up paint, and hit paste, then save as a .jpg
Jun 16, 2008, 06:20 PM
#471
1.000 lambda = 14.70 AFR (for normal gas)
Also a narrowband sensor becomes less accurate the further off stoic voltage it is, not the more it is used.
Last edited by razorlab; Jun 16, 2008 at 06:23 PM.
Jun 16, 2008, 08:15 PM
#474
Tuning engines is about finding optimal values for your engine. There are too many variables to tell someone exactly where they will make optimal power. The practical aspect of tuning the MIVEC map is not unlike tuning an ignition map. But it's important to understand what effect advancing and retarding the cams has at different loads / rpms.
Last edited by Mr. Evo IX; Jun 16, 2008 at 08:21 PM.
Jun 16, 2008, 09:48 PM
#475
FYI, I'm going to be dyno tuning my personal car on Monday on a Mustang Dyno with Brian Crower 280's, and I will take as much time as needed to dial in MIVEC.
I plan on initially making a run with the entire VVT map blocked at 0, and then repeat for 9.6, 19.2, and 28.8. Based on those 4 runs, I'll try to devise a single effective map.
This is on an FP Green @ 29psi on 50/50 Meth. The car previously made 350whp on this dyno and trapped 120mph on stock cams and no meth.
I plan on initially making a run with the entire VVT map blocked at 0, and then repeat for 9.6, 19.2, and 28.8. Based on those 4 runs, I'll try to devise a single effective map.
This is on an FP Green @ 29psi on 50/50 Meth. The car previously made 350whp on this dyno and trapped 120mph on stock cams and no meth.
Jun 17, 2008, 08:17 AM
#478
I should have said 0.5 AFR leaner. It went from 12.5 to 13.0 AFR (wideband), boosting only at 1 bar held. Same conditions, same boost, same fuel and timing, only changes were the mivec. Perhaps HKS cams like 24* and possibly 28.8* is too much advance for those cams. I do find it drives better at 24*, feels like less strain on the engine if that makes sense. I have no dyno proof of making more power but if it went lean that has to be a good thing.
Any ideas from the Mivec Guru's?
Any ideas from the Mivec Guru's?
Jun 17, 2008, 09:00 AM
#479
FYI, I'm going to be dyno tuning my personal car on Monday on a Mustang Dyno with Brian Crower 280's, and I will take as much time as needed to dial in MIVEC.
I plan on initially making a run with the entire VVT map blocked at 0, and then repeat for 9.6, 19.2, and 28.8. Based on those 4 runs, I'll try to devise a single effective map.
This is on an FP Green @ 29psi on 50/50 Meth. The car previously made 350whp on this dyno and trapped 120mph on stock cams and no meth.
I plan on initially making a run with the entire VVT map blocked at 0, and then repeat for 9.6, 19.2, and 28.8. Based on those 4 runs, I'll try to devise a single effective map.
This is on an FP Green @ 29psi on 50/50 Meth. The car previously made 350whp on this dyno and trapped 120mph on stock cams and no meth.
I'm playing with some BC 280s again this weekend and I'll post results if anything good happens. No dyno though ... just road tuning.
Jun 17, 2008, 10:48 AM
#480
The BC 280s don't like the excess MIVEC on the low end ... I couldn't run more than 25º without pegging the knock sensor at 36. I think the centerline is a bit different than stock ... i'm not big on cams and specs but these were definitely off somewhere..
I'm playing with some BC 280s again this weekend and I'll post results if anything good happens. No dyno though ... just road tuning.
I'm playing with some BC 280s again this weekend and I'll post results if anything good happens. No dyno though ... just road tuning.
The BC 280's made about the same power as stock cams on this Evo 9. I tried everything under the sun Mivec wise. Even 0 and full advance.
I really think these cams need to be degreed and have an exhaust gear to even work worth beans.