sweet, looking forward to it.

 

Very nice Jason. It is great that you are doing this. Thank you so much.

 

I could almost kiss you! But since I'm strait (and married)... How about a good ol "Thank you" and a hand shake?


You are my hero.

 

Code talk *I want to give you a moustache ride Jason"

Awesome job Jason. Looking forward to this.

 

hey man, i sent you some logs. hope this helps out. they are all with my tuner wideband datalogged in setting 1.


as far as the usb goes. my computer has automatically detected the usb cable a couple times and a couple times i had to physically install the usb driver that you get with the utec instruction pack. what i did do is i took out the factory bracket for the stock computer and i mounted the utec and stock computer together. then i turned the whole new computer sideways and used a couple straps to secure the utec in sideways. now i can reach all the cable connections cause they are all aimed down....





hey jason, if you want to be rich soon. figure out a simple way of controlling the variable cam timing and you will sell 1000s of them in the first week.

 

subscribing i <3 my utec

 

So I finally got my AEM hooked up and tried the EVO settings with the software. It works for about 15 seconds and then the A/F readings stop. Any attempt to disconnect the devices or close the software results in the blue screen of death CRASH.

 

WTF! No Dude..... NO.

 

I am using two USB-to-Serial cables and they are different (made by different manufacturers and use different drivers). This morning I swapped them and tried again. This time it ran longer, A/F worked for like a minute before stopping and the UTEC data did not work at all. It did not crash when I disconnected or closed the app. either. I am guessing that the cable is a POS. Going to CompUSA to get another cable and try again. But I still don't understand why the A/F would work for a while and then stop.

 

That may be the case. You may want to check out how well the cables are connecting in the USB ports, a bad connection (either from a crappy cable or a broken connector on the laptop). A loose connection would cause the COM port to go on/off-line on an intermittent basis. The program can crash if it tries to close a COM port that suddenly no longer exists.

-jason

 

What do you mean by this? The UTEC doesn't control the timing correctly? Or doesn't utilize the Variable Timing feature the stock ECU can?

-jason

 

Well with the 2nd cable, I can't even connect to the UTEC through HT. It thinks it is connected but never shows the UTEC control panel. I went to get another cable today but the only one I could find was overpriced and the drivers were on floppy (my laptop has no floppy drive). I guess I'll have to order one and hope I get a better cable this time.

 

Can someone please answer Jason's question on the off chance that he might have an answer for this?

 

Havok,

I believe you are referring to the variable valve timing that the stock ECU controls. The UTEC has NO control over this feature. To control it I'm thinking either the stock ECU will need to be relashed or you will need an additional box to drive the CVT solenoids with a user adjustable pulse width modulated signal.

 

Gotta love smart people.

 

Ditto. Creating a program to control VTC would be so great!

 

Does it really take a PWM signal and not just an on/off like say VTEC? What Frequency? What parameter drives the signal? ie: rpm or 2d map values?

Would it be possible to drive the PWM signal using the UTEC's spare solinoid output set to PWM mode. This gives you a 2D programmable PWM map with RPM x Load like the rest of the UTEC maps. Has anyone tried this?

-jason

 

The main difference between VTEC and CVVT is that VTEC is On/Off while CVVT is continously variable-ing, meaning its almost infinately adjustable between on and off.

Ther are two separate solenoids that control the system, a bank 1 and a bank 2. I can't imagine running them at different frequencys so it may just be a reliability thing to keep them separate.

The service manual actually shows what looks to be more of a duty cycle then a frequency, with a period of ~4ms and a 'on' time of ~2.4 seconds and an off time of ~1.6ms at 2500RPM. It would take a little time with an O'scope to get the exact operation of this system.

The real question is is what kind of gains can be expected from altering the control of this system? I would imagine the tuning is rather aggressive from the factory. We may be able to pull a few more ponies down low, but up top I wouldn't expect any gains at all.

It would also be interesting to disable the system and see what kind of power is LOST by disabling the CVVT system.

 

I wonder what algorithim is employed by the stock ECU in that regard. I'd be interested in seeing what the readings are when scoped. I wonder how continuously varying it really is... MY guess is to be sure you'd have to scope the input signal at each engine load and then do progessive increase and or decrease in load and monitor the signal to see if it passes through the readings taken at constant loads... Too bad Nissan won't cough up their prorgramming...but then again who would...

 

Any word on this?