Discussion and questions related to the course Link G4 Software Tutorial
Hello everyone, I am trying to get a Version 9 STi running in the modeled fuel mode on a plug and play Link G4+ and I am seeing some questionable values in my VE table. It likes to idle with a value of 70, and I have roughed in the map to about 10psi up to redline. My values start at 70 (idle) up to about 120 (peak torque) and back down to 100 (redline). The link forums say I should see values in the mid 50-ish range for idle up to about 100 for peak torque, I just wanted to see what you guys have to offer in terms of advice. I know for sure that I have the injector data entered correctly, I even called Injector Dynamics to verify that the plug and play data on their support page was updated for use on the G4+. I do not want to get too far into this VE table with something I might be overlooking and have these VE table values cause something funky later in the tuning process. I have already disabled the IAT comp tables per the link support forum suggestion as well. Are these VE table values normal? Is there anything else I should be checking to make sure the setup is correct before looking to turn up the boost?
Relevant information on the car is as follows:
V9 complete longblock (stock aside from ARP625+ head studs)
V9 Spec-C VF36 turbo and matching OEM twin scroll header/uppipe
Perrin turbo inlet
stock airbox with snorkel delete and K&N panel filter
I started tuning my ej20 a couple months ago with the link G4+ PNP and found the same with my values (idle 800rpm around 70 & peak around 115) .
I am also confident my ID1300 injector data is set up correctly so i assumed my VE numbers were ok even though they were much higher than the base values suggested by Andre in the road tuning course
It's not unusual to end up with VE values in the range of 110-125 in some instances. You need to remember that the modelled fuel equation is just a generic model that is designed to work adequately on a huge range of engines. It won't necessarily give you a pin point accurate VE number. That being said, one of the issues that can result in the VE values being skewed higher than you'd expect is if the fuel pressure is not keeping up. If you're not using a fuel pressure sensor as an input to the ECU then the ECU will work off whatever you're base fuel pressure is. It then assumes as the boost increases that the fuel pressure will keep track but often it doesn't. This means the fuel flow through the injectors is lower than the ECU expects and we compensate this by increasing the VE numbers.
The other factor many users forget about is the instrument that you are using to calibrate that VE table - the Lambda device...
It is not uncommon to see a difference of 10% between 2 different brands of wideband controllers, it is also not uncommon to see even more than that when viewed in the ECU software on some of the brands with poor quality analog outputs. I have tested one lambda controller that had a full 1.0 AFR of noise on the analog output when the sensor was in steady state nitrogen...