Email from Joe @ Cobb Tuning Regarding G37 Tuner Software.
07-24-2009 | 12:12 AM
#1
Email from Joe @ Cobb Tuning Regarding G37 Tuner Software.
Originally Posted by Joe @ Cobb Tuning
Hi Manny,
We have noticed the exact same thing that you have, no matter what we do to the timing tables the car runs the timing curve that it wants to run
I've been digging into the timing routines in the Nissans for weeks now and what I've found is that the values in the timing A and B tables are a starting point for cylinder pressure, and then the ECU will go and do a bunch of calculations based on temperature, RPM, Load, intake valve timing, exhaust valve timing, and a few other values that I still haven't figured out. As soon as I can figure out the logic that the ECU is using I'll add it to the tuning guide and what I can to the tuning software.
When Nissan tunes it's cars for different fuel grades they use Timing A and B (they tune A and B exactly the same) to effect the changes and they modify the tables exactly like they are a direct timing. Here is some of what I've been looking through.
This is a comparison of the EDM and Gulf Spec GT-R the last table is the Gulf Spec timing - the EDM timing. The differences are exactly what you would expect for different fuel grades.
One of the things that I've talked to our tuners about is the power numbers. Nissan says that the GT-Rs make the exact same power no mater what region the car is tuned for. To me that means that there is a lot of logic that goes on in the ECU that I haven't figured out yet.
Now you've been tuning the G37 not the GT-R, well Nissan uses almost the exact same logic on all of its V6 motors, but the G37 has the VVEL system that adds another layer of complexity to the timing algorithms. As I said above Nissan uses intake, and exhaust cam timing in their calculation for ignition timing and the VVEL logic is extremely complex. Trey is digging into the VVEL system on the G37 and 370Z and as soon as we understand that system we will add what we can to the tuning software and the information into the tuning guide.
As you can tell there is still a lot that we don't know about this car and a lot that we are working on, but I hope this info helps.
Joe
We have noticed the exact same thing that you have, no matter what we do to the timing tables the car runs the timing curve that it wants to run
I've been digging into the timing routines in the Nissans for weeks now and what I've found is that the values in the timing A and B tables are a starting point for cylinder pressure, and then the ECU will go and do a bunch of calculations based on temperature, RPM, Load, intake valve timing, exhaust valve timing, and a few other values that I still haven't figured out. As soon as I can figure out the logic that the ECU is using I'll add it to the tuning guide and what I can to the tuning software. When Nissan tunes it's cars for different fuel grades they use Timing A and B (they tune A and B exactly the same) to effect the changes and they modify the tables exactly like they are a direct timing. Here is some of what I've been looking through.
This is a comparison of the EDM and Gulf Spec GT-R the last table is the Gulf Spec timing - the EDM timing. The differences are exactly what you would expect for different fuel grades.
One of the things that I've talked to our tuners about is the power numbers. Nissan says that the GT-Rs make the exact same power no mater what region the car is tuned for. To me that means that there is a lot of logic that goes on in the ECU that I haven't figured out yet.
Now you've been tuning the G37 not the GT-R, well Nissan uses almost the exact same logic on all of its V6 motors, but the G37 has the VVEL system that adds another layer of complexity to the timing algorithms. As I said above Nissan uses intake, and exhaust cam timing in their calculation for ignition timing and the VVEL logic is extremely complex. Trey is digging into the VVEL system on the G37 and 370Z and as soon as we understand that system we will add what we can to the tuning software and the information into the tuning guide.
As you can tell there is still a lot that we don't know about this car and a lot that we are working on, but I hope this info helps.
Joe
07-24-2009 | 12:19 AM
#2
Very valuable information Cham! Seems Cobb isn't the only company stumped with the actual complex layout of the VVEL. I'm sure eventually they'll be able to crack it, but it'll probably take A WHILE. Until then, we can only play around with the air fuel and enjoy those added gains.
I still don't understand all the bash with Cobb either. At least they came out with the accesstuner software. That's more then you can say for the other companies at this point (Uprev). Uprev isn't going to give you cam timing either when it's first launched in the next month or two, so you're only going to be able to do the same options Cobb is offering currently.
I still don't understand all the bash with Cobb either. At least they came out with the accesstuner software. That's more then you can say for the other companies at this point (Uprev). Uprev isn't going to give you cam timing either when it's first launched in the next month or two, so you're only going to be able to do the same options Cobb is offering currently.
Last edited by Staples; 07-24-2009 at 12:30 AM.
07-24-2009 | 01:21 AM
#5
07-24-2009 | 02:55 AM
#7
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07-26-2009 | 02:44 PM
#9
I thought the VVEL was going to be a hard nut to crack. I hope Cobb has the time to devote to this. I wish Infiniti welcomed tuning like other companies, and shared technical white papers and ECU/TCU parameters like GM, Ford and Hyundia, etc. do with aftermarket companies..
07-26-2009 | 07:32 PM
#12
I thought the VVEL was going to be a hard nut to crack. I hope Cobb has the time to devote to this. I wish Infiniti welcomed tuning like other companies, and shared technical white papers and ECU/TCU parameters like GM, Ford and Hyundia, etc. do with aftermarket companies..
07-26-2009 | 07:46 PM
#13
They do have time to devote. If they crack this, they'll have the whole G37, 370z community. Cobb knows their chit, it just took them a while to come out with the software because there's really only 2 or 3 guys developing everything. I made over 13whp total with just leaning out the a/f ratios. I wonder how much extra power we could make with cam timing adjustability.
