Need help with Uprev

PunKidd · 12-29-2010, 05:23 PM

Fuel target lookup delay: This is really just an issue for forced induction on the V8s, but it couldn't hurt to zero it on the VQs as well (I set it to 0 on the VKs with no issues). Basically, the ECU will slowly taper to the new AFR target that is coming from the AFR target table lookup when you romp on the throttle and the look-up shoots to the far right. This turned out to be a problem on Titan superchargers because the ECU would still be targeting 14.7 or just below that when the engine was in boost if you romped on the gas. Reducing this value to 0 let the ECU go to the new AFR settings right away. The delay is hardly noticeable on the VQ engines, but the VK engines the delay can be as high as 1.5 seconds which is a lifetime at WOT.

Load point scaler: I think we're going to pull this one out of the editor. What it does is rescale the BFS axis on EVERY table that uses BFS for load. We though this would be a quick way to rescale and keep everything in line, but the problem has been that there are dozens of other tables in the ROM that we don't know about yet and their lookups get altered as well. It worked fine on the older 350Z and Titans, but it seems to be problematic on the VVEL cars. The issue we've seen on the VVEL cars is that they don't maintain idle very well once you've tweaked this value.

K fuel multiplier. This is basically your injector PW multiplier. A VERY brief explanation is that the ECU takes the value from the MAF table for whatever voltage you're at and multiplies that value by the K value to get the BFS (base injector PW). Of course it's more complicated than that, but that's the gist of it.
To tweak it for a new MAF tube will be just like new injectors or a modified MAF sensor. Start by setting up an "AFR Test" table in your AFR targets so that the ECU is ALWAYS trying to hit the same target as soon as you give it any gas at all. 12.6 is good for NA, 11.7 for FI (make sure it still cranks and idles at 14.7). Then get the car under some load. If it's consistently lean, raise the K to increase the injector PW, if it's consistently rich, lower it to reduce the IPW.

Once you have the K set so that the car is hitting the requested AFR MOST of the time, you'll do the rest of the AFR tuning either with the fuel compensation or the MAF table.
Fuel compensation is pretty straight forward. Just watch the tracer and rise the values where it's lean or lower them where it's rich.
For the MAF, you just need to data log the MAF sensor voltage along with the AFR and make similar tweaks. Any voltage where the AFR is lean, raise the values, and where it's rich lower the values.
Now that the ROM editor does data logging, map tracing, and real time tuning all at the same time it makes the process much quicker.
We'll add a feature soon to chart two parameters against each other, like AFR vs MAF, which will make MAF tuning quite a bit faster as well.

Jared@UpRev.com

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12-29-2010, 05:23 PM	#2 (permalink)
PunKidd Base Member Join Date: Nov 2009 Location: Austin TX Posts: 10 Drives: Lots of fast cars Rep Power: 17	Fuel target lookup delay: This is really just an issue for forced induction on the V8s, but it couldn't hurt to zero it on the VQs as well (I set it to 0 on the VKs with no issues). Basically, the ECU will slowly taper to the new AFR target that is coming from the AFR target table lookup when you romp on the throttle and the look-up shoots to the far right. This turned out to be a problem on Titan superchargers because the ECU would still be targeting 14.7 or just below that when the engine was in boost if you romped on the gas. Reducing this value to 0 let the ECU go to the new AFR settings right away. The delay is hardly noticeable on the VQ engines, but the VK engines the delay can be as high as 1.5 seconds which is a lifetime at WOT. Load point scaler: I think we're going to pull this one out of the editor. What it does is rescale the BFS axis on EVERY table that uses BFS for load. We though this would be a quick way to rescale and keep everything in line, but the problem has been that there are dozens of other tables in the ROM that we don't know about yet and their lookups get altered as well. It worked fine on the older 350Z and Titans, but it seems to be problematic on the VVEL cars. The issue we've seen on the VVEL cars is that they don't maintain idle very well once you've tweaked this value. K fuel multiplier. This is basically your injector PW multiplier. A VERY brief explanation is that the ECU takes the value from the MAF table for whatever voltage you're at and multiplies that value by the K value to get the BFS (base injector PW). Of course it's more complicated than that, but that's the gist of it. To tweak it for a new MAF tube will be just like new injectors or a modified MAF sensor. Start by setting up an "AFR Test" table in your AFR targets so that the ECU is ALWAYS trying to hit the same target as soon as you give it any gas at all. 12.6 is good for NA, 11.7 for FI (make sure it still cranks and idles at 14.7). Then get the car under some load. If it's consistently lean, raise the K to increase the injector PW, if it's consistently rich, lower it to reduce the IPW. Once you have the K set so that the car is hitting the requested AFR MOST of the time, you'll do the rest of the AFR tuning either with the fuel compensation or the MAF table. Fuel compensation is pretty straight forward. Just watch the tracer and rise the values where it's lean or lower them where it's rich. For the MAF, you just need to data log the MAF sensor voltage along with the AFR and make similar tweaks. Any voltage where the AFR is lean, raise the values, and where it's rich lower the values. Now that the ROM editor does data logging, map tracing, and real time tuning all at the same time it makes the process much quicker. We'll add a feature soon to chart two parameters against each other, like AFR vs MAF, which will make MAF tuning quite a bit faster as well. Jared@UpRev.com