Discussion and questions related to the course Reflashing
Hi, i have a frs/brz with ID1050x jackson racing supercharger tuned with speed density. im in the middle of tuning it but i can't seem to be able to keep the direct injection timing above 6ms, i have tried adjusting injection ratio and DI angle tables but it doesn't seem like helping much. I have a log in attachment, thank you in advance.
Hi Henry, first of all is there a reason you want to have the DI injection over 6ms? You need to consider that the available window for injection with DI is only around 25% of the engine cycle and this limits the pulse width you can run. In this case for example if you were operating at 6000 rpm the engine cycle time is 20 ms and 6 ms DI would represent 30% duty cycle which is too much. From your log I really can't fault what you have currently. You can increase the DI fuel injection by adjusting the numbers in the DI/PI ratio table as required, keeping your DI limit in mind. Currently that's set to 44% at 6000 rpm/high load by the look of your log and the fuelling appears to be following that.
I just thought i needed more DI but I believe I got that all sorted out. The fuel are also following as well, was having problems breaking up at top end and with a cel flashes. it was misfiring up top but my injection DI time is no where near 3ms so I went ahead and play with the injection angle a little bit.
The top end is still breaking up flashing cel. Here is a datalog i could also provide tune files if that helps. i've tried playing with the PI.DI ratio, it gets better but still breaks up. Also noticed the AFR goes rich in the middle of the pull even if I pull fuel out. I’m not sure what the problem is
Hi Henry, apologies for the slow reply. I've had a look at your latest log file and a potential issue you may be facing is that the fuelling is very rich. Given the relatively low boost level you're running I'd be targeting around 11.5:1/0.78 lambda.Your target through the midrange is 11.68 which is probably fine, but then it targets 10.96 at 7000 rpm which is very rich. Not only is your target a little rich but you're also not tracking the target correctly with your midrange fuelling pegged at 11.02 which is the richest the sensor will report - You could literally be anywhere richer than this and you have no way to tell. The other issue is that the factory sensor doesn't read accurately when you're this far from stoich - Despite it being a true wideband sensor it's still predominantly used at or very close to stoich. If memory serves correctly the sensor tends to report leaner than the actual AFR, compounding the issues you may be facing.This is why I prefer to bring in a proper wideband to verify.
There may be some other factors at play here and I'd chek to ensure you've raised the load limits to suit FI too. If you have no luck then please post your current calibration and I'll take a look.