VVT logs

Tuning concepts, methods, tips etc.

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nismoautoxr
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VVT logs

Post by nismoautoxr »

Never messed with VVt but I am trying to . The car is a 02 miata . Here is the MSQ and a log I took this morning when I look at the trace for VVT1 angle and VVT target, the target is as youd expect in the log moving up and down with load and rpm but the angle is pretty much static at 22 to 23 degrees no matter the condition . Ive tested the ocv in test mode and it works and Ive tested it running at 80% duty it will kill the engine at idle when activated so I think the phaser is responding to the ocv during that test . is the angle supposed to mirror the target? Somebody that knows what they are doing please gimme some pointers
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
nismoautoxr
Super MS/Extra'er
Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

Nobody??
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
Matt Cramer
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Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: VVT logs

Post by Matt Cramer »

Try reducing the minimum VVT duty to 0%. I've noticed it is going to 20% duty and still not retarding the cam enough.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
nismoautoxr
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Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

Thank you. Ill try that when the car comes back.I sent it off for paint .
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
nismoautoxr
Super MS/Extra'er
Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

OK I finally got my miata out of the paint shop from getting a total respray and its time to revisit this odd VVT issue. Or it may not even be an odd VVT issue ...may just be operator/tuner error but for the life of me I cant get the cam to go below 22 degrees no matter what. it stays fixed at around 22 and 23 degrees. If I test it on the VVT settings menu it does nothing until around 77 or 78% duty and then it starts to dramatically advance the cam and by 80% duty itll max it out and kill the engine.
Why will it not go below 22 degrees? Does this sound like a mechanical phaser or oil control valve problem? Ive tried different frequencys and all sorts of fiddles but nothing seems to have an affect. Can someone familiar with this VVT system on a miata shed any light? Here is the tune as it is now and a log.Please help me.
With a stethoscope I stepped from 0 duty all the way to 80 and I could hear the frequency of the oil control valve change so it is at least operating electrically but it is like a buzzing rather than a clicking even at 1% duty if that means anything?
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
nismoautoxr
Super MS/Extra'er
Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

NOBODY????? Surely somebody has some input on this ...don't be shy? No MIATA guys here?
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
Matt Cramer
Super MS/Extra'er
Posts: 17499
Joined: Thu Apr 16, 2009 8:08 pm

Re: VVT logs

Post by Matt Cramer »

If it won't go below 22 degrees in test mode, make that your minimum.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
nismoautoxr
Super MS/Extra'er
Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

I would.be fine with doing that if the system seemed to be operating correctly but it doesnt seem to be. It does nothing until 77% duty and by 80% its all in . That doesnt seem too controllable. Also the frequency of fidle and vvt MUST match...otherwise u get a configuration error .
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
jsmcortina
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Re: VVT logs

Post by jsmcortina »

Have you installed a diode across the VVT solenoid or added the flyback jumper wire on the MS3X card? In early testing some customers found that solenoid operation wasn't as controllable without that.

The frequencies thing is a hardware restriction. The PWM channels in the processor itself are in two groups and share one frequency across the group.

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
nismoautoxr
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Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

No I havent James . I wasnt aware of that . The way its working atm ....its unpredictable in test mode. It literally will go from 22* at 76dc to 65* in a matter of a couple % duty so if the flyback is something I need to do then I will because the idle valve works best at 383mhz.
In my past Ive alway been told that more retarded cam timing enhances hiigher rpm torque and more advanced timing enhances low rpm torque. Is that true or do I have it backwards?
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
jsmcortina
Site Admin
Posts: 39585
Joined: Mon May 03, 2004 1:34 am
Location: Birmingham, UK
Contact:

Re: VVT logs

Post by jsmcortina »

For MS3X jumper wire, see here:
http://www.msextra.com/doc/pdf/html/MS3 ... 4-221.html

James
I can repair or upgrade Megasquirts in UK. http://www.jamesmurrayengineering.co.uk

My Success story: http://www.msextra.com/forums/viewtopic ... 04&t=34277
MSEXTRA documentation at: http://www.msextra.com/doc/index.html
New users, please read the "Forum Help Page".
nismoautoxr
Super MS/Extra'er
Posts: 2631
Joined: Sun May 29, 2011 10:28 am
Location: birmingham ,Alabama. U.S.A.

Re: VVT logs

Post by nismoautoxr »

jsmcortina wrote:For MS3X jumper wire, see here:
http://www.msextra.com/doc/pdf/html/MS3 ... 4-221.html

James
Thanks James . I'm probably going to do that . I took DIYs advice and used the 22* as 0 and just added 20* to the whole vvt timing table and it works surprisingly well as it is. The commanded and actual angle mirror pretty well even with the small window of duty cycle. The car runs noticeably better and the turbo seems to spool a little sooner as well. I like it so far.
Ricky-
1995 Nissan 240sx, 403 LS strokerv8 N/A 6speed trans
MS3&MS3X v.3.0 PCB
42lb/hr Hi-Z inj.,230/232 @.050 on 114LSA cam
sequential fuel and sequential spark
LS3/LSA card MAF sensor
97 Mazda MX5
MS3 2002 vvt motor
.60 trim T4 Turbo at 15 PSI
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