Vit's FI TT 370Z Lives!

Elmo370z

So i plan to stay N/A, Hopefully in the near future I"ll be able to afford a dry sump and B.R. billet crank to build the bottom end to rev safely rev to 9k. Similar to OnPoint DYno's 350z, do you think ecu tek would be more than plenty or could this kit greatly improve tuning capabilities over ecu tek.

VitViper

The goal of any good TC system is to run the car at the limit at the tire without hurting acceleration. The M1 does this with ease.

The stock ECU sucks at this, as it's designed to keep you from wrecking and nothing more.

ECUTek will never touch the logic in the motec, I've already spent a lot of time adjusting settings and with a turbo car you'll still spin the tire (especially 1st gear) even if you pull AALL the timing out of it (this motor just makes a ton of torque with twins lol). I have an intricate timing + throttle pull on my ECUTek map, the results are "meh" and nowhere near optimal. Better than the stock VDC, but not even 1% of a motec, lol

Yes this will in at least one facet -- you can setup a shift light module in the car to let you know when you're at 9k or higher -- the stock tach goes to 9k but the CAN bus RPM data only goes to 8400, trust me. lol

Beyond that I can't really answer that -- everyone has their own goals and needs. I just converted an 07 Civic Si to an M1 and built the car a dual fuel system firmware package for the ECU -- goes between E85 and M5 fuel at the flip of a switch in the car (4 cylinder 2.5L motor with 8 injectors, 2 pumps, 2 regulators. eg, two complete and segregated fuel systems run by the ECU based on driver demand).

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

VitViper

Just settle on the fact your ECUTek map can't and won't do what the MoTeC ecu is doing. In fact I have yet to see any OEM ECU do this as they just implement VDC and the goal is just to keep you from dying and not optimizing acceleration.

Timing retard does not work. Throttle closure does not work.

We target a set driven wheel speed based on non driven speed and hold it there. The driven wheel speed must ALWAYS be a certain amount faster than non driven to have "acceleration" (otherwise you're standing still lol). When you have too much is what "overslip" or "wheel spin" -- the tire couldn't hold traction and RPM takes off and you spin. This won't ever happen with a proper M1 setup. It'll just hold. The how and why is beyond the scope of this thread, lol.

Best I can do is show you -- this is of our 910whp FWD cars (about 750 in the video). Video has a tach & vehicle speed playback part way in, you can see the RPM never breaks out into wheel spin.

https://www.youtube.com/watch?v=6N2IqmAYkxw

Jhill

Ok I think the video helps. Looks like it's doing it through a fuel cut so the rpm stays down.

BehindSpace

dude, just google motec traction control and read up on it.

its a 3d table where you set a target slip ratio for your calculated maximum acceleration based on vehicle speed and throttle position and the ecu wont let it go past that based on what position you are in the table.

phunk

He is asking "how" not "when"

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VitViper

It's not a fuel cut. The underlying code & logic in the ECU is more complex than the simple explanation: it's a selective cylinder drop designed to hold your at your target driven to non driven speed ratio ("slip").

I took the car out for it's first drive today, got the base sync done, fresh oil in it (4k miles on the original oil since I TT'd it), things went smooth so far! Lots of work to do still -- Navi MPG gauge works pro. The data gauge MPG is off a bit, and I'll have that rectified in my next update.

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

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.

Spooler

This thread makes me feel poorerer....LOL

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 .