Vit's FI TT 370Z Lives!

Jhill

So if I am understanding this right then it sound like your controlling traction based of a predetermined allowable toque output so you never break traction in the first place? Vs a conventional system that is all cause and effect (slip then react). So wouldn't you need to recalculate your table everytime there is a change (tire, track, weather etc.)?

VitViper

Torque has nothing to do with it. There's a set target driven speed based on a ratio off the non driven speed. Acceleration always requires some slip -- the optimal amount is the limit of the tire. You figure this out, plug it in, and it just holds you on the tire. No "error -> correct" ******** from PID or gain based systems.

And you have the ability to trim the system with the dial to adjust for wet/cold/hot changes. In the case of the Z, it'll be adjustable with the cruise buttons.

Jhill

Lol ok so in still confused. If at any time you get frustrated explaining yourself just say and I'll stop but in really interested in how this works. So my ecutek tune is adjustable through cruise like yours and I assume it's just an amount of retard vs % slip.

So if yours is not doing it through timing or throttle how does it work? What happens?

Say I'm on wet/greasy surface and at a stop, I then slam throttle 100% to the floor like an armature. How does yours work to prevent slip? It has to cut power some way right? I mean if I was twin turbod 480+ torque I obviously couldn't allow all 480 down and hold it on that surface instantly or all you would have is spin right?

Sorry I'm just confused

phunk

Sounds sort of like a pro-active racelogic. Selective drop but predictive rather than reactive.

I think the confusion was just more so that nobody was explaining the motecs method of power reduction. If its a cylinder drop, I think its safe to assume it skips injection cycles as necessary.

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Jhill

Yea I found a video on the motec that explains it better. That's sounds really cool. It's like active traction control vs reactive control. Pretty neat.

VitViper

"Proactive" instead of "reactive" I guess would be a good way of putting it. If you (tuner) put in the right settings, the ECU knows where the limit it, and just won't let you get there.


Got off the dyno today and got 80% of the work done. Turns out the bank 2 cam position sensor is indeed bad (my stock ECU has been hitting limp mode from time to time without throwing a CEL -- when I scanned the ECU last it was a pending bank2 camshaft position code), the MoTeC picked up on it soon as the sensor went on the fritz (it's been intermittent). I have a new sensor but left it at the house -- doh!.

You can see where it goes low and then goes REALLY low and gets stuck there, lol.

http://blog.vittuned.com/wp-content/...c/cam_code.png

The POS chinese fuel pump finally took a crap, loses all fuel pressure past 7psi at high rpm.

http://blog.vittuned.com/wp-content/...ssure_drop.png

Nice to be able to log and catch all this and build in failsafes for it. For you guys on the stock ecu -- all the 300/320/340 pumps are made in China. Used countless ones now, they are extremely hit or miss. Watch out.

Knock detection works.
http://blog.vittuned.com/wp-content/...nock_logic.png


All in all, got what I needed to test tested. Went very smooth -- I stopped at about 510whp on pump gas, and I made this on a very conservative timing and cutting the run short (6900-7000 rpm) due to the cam sensor & fuel pump. Within about 20-30hp of where I ran it when I initially tuned it -- about what I'd expect for the 40-45* celcius IAT's in my 100* shop today vs the 20* celcius IAT's I had in the dead of winter when I tuned it originally (anyone questioning whether this helps make power -- absolutely, want big numbers, tune when it's cold, the SAE correction factor isn't every going to make up for the fact the motor makes significantly better power when it's cold and not knock limited by the hotter charge temps lol).

But will it shoot fire?

Yes, soon as the sun goes down, lol

https://www.facebook.com/vittuned/vi...9134603631539/

VitViper

Took the car out for a good hit today, just running 7psi to stay under the limit of the fuel pump lol. It's a whole new car -- response is better, boost comes in much better (to the point I gotta dial it back a bit).



So nice to have true closed loop boost by gear!

The knock control is great, I honestly have the threshold too tight right now since I'm experimenting and making sure it all works well.



I'm also using the lateral G's coming from the ABS/VDC to trim the traction control -- so as you pull lateral G's the system hunkers down, works great!



One of the challenges of the VVEL motors using a VE based system -- making sure fueling is correct as it can vary DRASTICALLY based on the VVEL target (even based on TPS vs VVEL at points). It's a fantastic system -- I love it. I've found I can set VVEL targets that make just enough power to just cruise down the high way, but even if you floor it (100% TPS) the car won't accelerate or barely creeps, LOL.

But back to the fueling -- you can literally spend hours upon hours to get it all "right", but I don't want anyone to spend that much fiddling with it, so I've already done most of the work in dialing in the VVEL comp tables.



But this still won't be 100% perfect, and me being really picky, I want it perfect -- so what do we do? I programmed the ECU to learn, either while you're on the dyno or just driving the car, then it applies the learned VE trims and you have spot on fueling. You can disable learning once you're happy with it and only let it apply (IE for long term in case your lambda sensors fault, you don't want the learned tables skewing anything).

Yes it retains the learned data between engine key cycles, it's flash backed .

Jhill

Man this is way more than I need but way cool!!

So is this your own stand alone unit you made or modifying another stand alone? Really cool system, reading more and more about tuning and stand alones in general and it's pretty amazing what can be done now.

Spooler

This thread makes me feel poorerer....LOL

PongSanity

Ballpark price on stand alone?


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Elmo370z

3000-10000. Syvecs s6 unit should also fall inbetween that price range.

VitViper

6k+, retail on an M150 is $3770. I'm familiar with Syvecs, however I don't see them having a full drop in replacement ECU for the 370Z with VVEL control, CAN BUS programming, cruise control, working fuel economy meters, etc. Any ECU targetted at a 350Z *will not* work on this car. An S6 unit also will not run everything on a 370Z -- it's only got a single lambda, single knock input, etc. It's a very basic ecu.

Borrowed a buddy's Go Pro, took the car out for a spin. You can see/hear the traction control logic at work.

https://www.youtube.com/watch?v=ykO6e4L7trY

I <3 how the car sounds with the F/I kit & exhaust.

Elmo370z

There is one in the works for the 370. I gotcha, I was giving a ball park pricing.

VitViper

I saw. My system/package is more advanced and has full control of the VVEL, not just CAN to the module. I've already been running/driving the car for almost 4 months. I'll never go back to being tied down to someone else's programming from a world away -- and we can provide better support for a system that I built.

Elmo370z

I know, I've been watching both closely.