I've been reading through the forums and S4wiki tuning guides and just getting started trying to write a tune. I am trying to get a head start on learning how this works by reading through the community tune threads and the s4wiki page while I wait for the spare ECU I ordered to arrive. My current challenge is figuring out the KRKTE and TVUB for the injectors in my car.
I have Bosch 0280155892 (from the TT225) in my AMB 1.8t (2003 A4).
I am pretty sure I have figured out KRKTE
Info from
https://www.injectorplanet.com/collections/bosch-fuel-injectors/products/bosch-0280155892-volkswagen-06a906031j-1That lists injector flow as 374.1 cc/min @ 3bar so I used
https://deatschwerks.com/en-ca/pages/fuel-injector-calculator to get the flow for 4bar (431cc/min)
KRKTE = 50.2624*(1.781/4)/(431*0.684) = 0.075913
Does this seem like a good starting value? Stock is 0.1039 with the 263.8cc/min injectors (taken from the community stage 1 thread for 8E0909518AK)
If I do the same calculations for the stock injectors I wind up with 50.2624*(1.781/4)/(304*0.684) = 0.10763 which is close ish...
Now I can't find the TVUB values, and I can't seem to find any datasheets for these injectors, if anyone knows where I can find these please let me know.
Or maybe given I can't find a datasheet should I just try to get the TVUB values empirically via idle STFTs? I am just looking for a starting point given I can't flash the car yet.