VVT observations - current vs. advance
#21
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Edit from prev post: 3D table means two axis plus values? I guess I was thinking of that as a "2D table", since that's a 2D array. Anyway, there's an boost control table for RPM/TPS which I bet could be easily perverted to some other analog in. So I'm not sure it couldn't be done. I hope not, since I was planning on doing it.
Wasn't someone (reverant?) working on a stand alone VVT board?! Anyway, overall, I think as long as you have a stand alone PID routine, the advancing or retarding could be taken care of externally.
Wasn't someone (reverant?) working on a stand alone VVT board?! Anyway, overall, I think as long as you have a stand alone PID routine, the advancing or retarding could be taken care of externally.
#22
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In other words, I could check out the valve, and the code, as soon as I test my adapterboard and get that project off my plate. :-)
#23
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Seems Kevin is working on designing a controller as well:
What have you done to your Miata/MX-5 today? - Page 81 - Mazda Forums
What have you done to your Miata/MX-5 today? - Page 81 - Mazda Forums
#25
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Seems Kevin is working on designing a controller as well:
What have you done to your Miata/MX-5 today? - Page 81 - Mazda Forums
What have you done to your Miata/MX-5 today? - Page 81 - Mazda Forums
Semantics. Anyway, sure, 3-D it is then.
#28
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Greetings all. Sorry I missed this thread as I don't log in as often as I used to. I am indeed building a VVT controller and so far everything is working short of a tune. The board uses the OE CKP/CMP sensors and corrects the signals for use with a typical NA MS installation. Furthermore, the controller operates the OCV via a 2D table via RPM vs. load. I'm considering correction for air temperature as my instinct says I should, pneumatically speaking, but I'll cross that bridge when I come to it.
Thus far, with a loose PID tune, the camshaft advance tracks the set point derived from an interpolated 12x12 table. There's a touch of over/under shoot, but that is easily corrected through the PID settings.
I'll check back and update as often as I can. In the mean time, I've posted a few pics of the process: Picasa Web Albums - Kevin - Miata VVT Con...
Thus far, with a loose PID tune, the camshaft advance tracks the set point derived from an interpolated 12x12 table. There's a touch of over/under shoot, but that is easily corrected through the PID settings.
I'll check back and update as often as I can. In the mean time, I've posted a few pics of the process: Picasa Web Albums - Kevin - Miata VVT Con...
#30
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Any in particular? There really isn't much to it other than an Atmel ATMega168 with a bit of programming
![wink](https://www.miataturbo.net/images/smilies/wink.gif)
I drove the car for the first time since Sunday this evening (been busy with a few other things on the car). I dialed-in the PID settings a bit closer with only a degree or so of overshoot) and settling in less than a quarter second (according to the logs, anyway). Overall response seems very good. I have a dyno session scheduled in the morning (Friday) to tune out the entire works). Wish me luck!
Last edited by kcbhiw; 08-20-2009 at 10:23 PM.
#31
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Very nice! Too scattered to think of a good question now.
I want to have the MS do this. I'd like to see the PID code, too. :-)
Oh, what I meant: The MS knows about all the events, from signal processing to timing, you SHOULD be able to get it out over CANBUS or something. The MS-II now (experimentally) reports cam-phase.
I want to have the MS do this. I'd like to see the PID code, too. :-)
Oh, what I meant: The MS knows about all the events, from signal processing to timing, you SHOULD be able to get it out over CANBUS or something. The MS-II now (experimentally) reports cam-phase.
#32
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#36
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Kevin,
Great work! I am in need of a standalone VVT controller. I have a TEC2 running an 01 VVT motor in my 94 CSP car and obviously it is not controlling the VVT. I used an MSD switch for a while but I need to have full control. So, if you decide to sell some, I am interested!
George
1994 MX5 CSP
1997 EK G2
#37
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The PID settings did not have to be changed throughout different RPM or MAP bins.
Thanks!
The car picked up 32 HP over the '99 engine I had in there before hand!
Kevin,
Great work! I am in need of a standalone VVT controller. I have a TEC2 running an 01 VVT motor in my 94 CSP car and obviously it is not controlling the VVT. I used an MSD switch for a while but I need to have full control. So, if you decide to sell some, I am interested!
Great work! I am in need of a standalone VVT controller. I have a TEC2 running an 01 VVT motor in my 94 CSP car and obviously it is not controlling the VVT. I used an MSD switch for a while but I need to have full control. So, if you decide to sell some, I am interested!