AbeFM

iTrader: (3)

I'll let you find out and bring my by the shop sometime. I wanted to show up with a handful of accelerators but the ones I was looking at were digital only, so I think I'll just pick up a couple of the ones Jason was talking about.

Dearest 18psi - I've been calling on the forums for some change, as usual no one is very receptive there.

Uncheck "Range Check Measured Angles", you'll probably get something crazy like 340 degrees. The code, in it's infinite wisdom, while understanding that sometimes you'll drift into the negative territory, they don't assume symmetry. They think you're more likely to see +320 degrees than you are to see -5.5 degrees.

So if it sees the cam go 0, -1, -2, -3, -4, -5 it tells the algorithm you're suddenly at +300 degrees, and tries to retard. It sets everything else wrong.

Basically, reset your upper and lower limits, it should fix it. Then, please add a voice to the thread on MSforums: Abe's VVT Bitchfest Thread and tell them you've had the same issue. My own feeling the the gauge should be symmetric about the midpoint of your range. Anyway, it would be nice not to see ridiculous behavior when it's a few degrees out from where it should be.

Ben

iTrader: (33)

Manifold pressure has less effect than RPM.

Ben

iTrader: (33)

I'm not on the code team, but as I understand it, there is built in +/-5° (relative to crank) of error prevention. I don't see why this wouldn't work great so long as the absolute min/max angles are set correctly.

AbeFM

iTrader: (3)

Sure! It's the behavior that it exhibits when you're out of range for whatever reason. There's really no reason to behave at 50 degrees OVER advanced, but fall apart at 5 degrees under....

Anyway, it caused very odd behavior in my case which took the forums weeks to figure out because it's non-intuitive.

Ben

iTrader: (33)

Was your minimum value set incorrectly?

AbeFM

iTrader: (3)

Yessir. Rather, I'd slipped the cam a tooth after a timing belt job. But the code wouldn't show it because it was limited to -5*, and it acts weird when you're out of range. My feeling on PID control (which doesn't work on pretty much ANY of the MS's control stuff) is that if you're below target you go up, and if you're above target, you go down.

This has been a decade's worth of contention between the coders and I - and since they now don't release source code for so long as to make it irrelevant, there's really no point in fighting it.

I thought if I played nice and said I'll do it your way, they'd at least help me to get the idle working, but they are still ignoring it no matter how much I ask. It's a class in psychology to get a straight answer out of them and I've pretty much just given up.

I feel like it's always a pissing match with who's smarter, instead of "how can we fix what's wrong with the code, and/or how can we explain to you how to make your car run as advertised with the code that's available". I'm not interesting in "being right" and I'll wear a t-shirt that says "The guys who right the MS code are smarter than me and satisfy women better", if they'll just make my car stop stalling.

All that said - yeah, when you're more than 5 degrees below your target, you get non-sense numbers and the controls are nonsense as well. If you get weird extreme-to-extreme variations, check to make sure you set your limits right.

18psi

iTrader: (76)

AbeFM,
Thank you SO MUCH for your input/suggestion. I haven't had a chance to try it, but will as soon as I can. I will post up the results.
I feel like everyone was intentionally ignoring my question. Really thankful for your response.

AbeFM

iTrader: (3)

Keep me posted. I can find myself out of my depth rather quick, but it's an easy thing to check - perhaps you even made the same folly I did and got the cams off a tooth.

Pedronomix

Noob' here.

Fine forum this, very high quality technical inputs, impressive to say the least. There are some really off the wall Miata/MX5 sites/FB pages/Forums out there

I have a 90 Mk1 fitted with 1.8 VVT/6 speed etc. 421, induction kit etc and want to add a DIYAUTO tuner piggyback. All I have read is pretty impressive when compared to an off/on/off standalone switching as in the OMEX.

What is the current best starting point map for this unit?

Thanks

Peter

AbeFM

iTrader: (3)

Probably the real question is why add a piggyback? There are so many better, much more comprehensive solutions using a stand alone that without a solid reason to use a piggyback, you'll just create a lot more problems than you solve. I went from an engine a year to one a decade when I switched - which wasn't ALL the fault of the piggy, but certainly contributed in most cases.

What is it that constrains your build?

Pedronomix

I have an expensive nearly fully functioned mapped OMEX ECU that just needs a VVT controller added on. Omex, for those not familiar would be the go-to Ford VTEC/EcoBoost ECU in Europe. Just does not have proper VVT/VTEC/VVC control, add it in seems the way to go to me!

PS I forgot it is Labour Day stateside today!!

AbeFM

iTrader: (3)

Ah. Yeah, there may be better folks to ask than me! From what I've heard, folks like the one they make.

As far as a map, DIY likely has something, but if not, the one I used from earlier in this thread seems to be awesome - though with MS's dubious idle control, it seems to be more trouble than it's worth under like 1200 rpm. I'd try what's here, but if that doesn't idle well, you could flatten it out down there. Then again, having a FIRST generation aftermarket oil pump gearset from Boundry engineering, I'm not sure I get full/consistent pressure at low RPM so that could be part of my problem.

Things got a lot better when I put my cam trigger wheel on, but I've yet to make a proper "product" out of it yet. :-)

EErockMiata

https://www.miataturbo.net/megasquir...u-69111/page2/

should work fine as far as i can tell. All the vvtuner really needs is a signal from your cam and crank sensor and it should work. I use vvtuner along side my oem ecu to pass smog on my vvt swapped 99. I'm not sure if there is any fundamental difference between the 01+ cam and crank signals that would require different settings...

AbeFM

iTrader: (3)

The crank trigger wheels are identical from 99-06 - I believe they even used the same crank trigger as far back as 95 or something.

The camshaft is a LITTLE different between the NB1 and NB2 - the cam's "doublet" is centered opposite the singlet on the NB1 while it's offset such that the first tooth lines up across from the singlet's tooth on the NB2.

If you want to run the stock ECU I think you'll be ok, as with the cams on the right tooth it'll never cross - I've seen some camshaft sensors which don't like the VVT cam's trigger wheel, but so far the ones specifically sold for Miata's behave till they cook.

Pedronomix

i am running an aftermarket missing tooth front disk on the front pulley to trigger crank pulse to ecu.

AbeFM

iTrader: (3)

Depending on your software, you should be fine. It's easy enough to figure out - put 12V on the soleniod, that'll advance the cam fully. If your ECU is ok with that, nothing the VVT controller can do will make it any worse than that. You'll probably have to manage the throttle to keep it running, but a few "full advance, full retard" cycles will tell you quickly if it's working.

You MAY have to move your missing tooth to a "safe" spot that the cam never crosses - that just depends on how the code on your ECU works. I run a similar set up (36-2, though 36-1 works just as well if not better I think) and a custom cam trigger.

psyber_0ptix

iTrader: (4)

Was there a definitive OTS intake relative timing table to plug into for VVT, or must it all be tuned per motor?

All of my values are set to 0.

AbeFM

iTrader: (3)

It's an "advance from fully retarded" that's more or less consistent across all the motors. The little timing wheel on the back of the cams isn't keyed - I don't know to what degree the cam can be phased relative to that - but everyone seems to have a few degrees of variance in their set ups.

In short - the offset table is right, but you may need to move the whole thing some small amount to account for your particular "zero". When I knocked off the OEM wheel and put on my own, it was the same deal - I kept the table and just moved the "0" in software and got all my timing back.

I think this post of mine has the best table - but read it carefully to be sure.

https://www.miataturbo.net/megasquir...2/#post1036306

psyber_0ptix

iTrader: (4)

Thanks for the info. I hope to have time this weekend to tinker with it. I imagine this will completely screw with the VE table afterwards eh?

AbeFM

iTrader: (3)

Pretty much yes. :-) And, to a lesser degree, timing.

You can also set up the injections to be timed relative to the cam position - but I'm not sure there's a way for your two boxes to talk about that, right?

If you could set it up to leave it full retard for the first few seconds you're running, I think you'd find that makes it start better. I'd love to do it on mine - it's struggling, sometimes, to control the cam before full oil pressure is established - and I worry that that oil draws from the rest of the motor's supply. Probably nothing. :-)

As an aside: Did you slip your cam a tooth? When I built mine (before I had VVT control) I did, to get the cam in a SANE spot. For 301 hp I figured you'd have something SOMETHING right - so I wonder how you got around it. :-)