NefMoto

Hi guys i just got 470cc Bosch injctors installed on my 1.8T . I calculated theoretical KRKTE 0.06961 for this injectors but my STFT still goes to up to -25% at idel. I dont konw dead time offset and could not find any data about so i let my TVUB stock.

KRKTE= 0.06961

         V 8             10              12            14          15.9
TVUB = 2.1040   1.3110   0.9105   0.6622   0.4913

Can someone pls hlp me out how to calibrate this injctors. I will attach a log if needs. 

Bad choice of injector type.
This injector has a high nominal voltage (14.5V) instead of 12V for the original 1.8T injectors.
Nominal Q-stat is 443 cm^3/min at 3 bar fuel pressure.
So at 4 bar Q-stat will be ~505 cm^3/min
It also has a different alpha spray cone and spray bent angle. So it "pisses" on the manifold wall instead of directing it to the valves. So it will work poorly at idle.
One more thing. Fuel pressure is different depending on the type of 1.8T engine - longitudinal (4bar оr 4bar-returnless) or transverse (3bar).
Which one do you have?

TNX for the input gremlin
It`s a Audi A4 B6 1.8tQ longitudinal engene with 3bar FPR (converted from rutrnless to non-returneless fuel system). Everything was fine untill i have fitted 470cc injctors. befor was 310cc.
I got em cheep fom a guy, so i thout its a maybe worth efford to fitt em up coz the old one was running at max IDC

I set FKKVS all to 1
NOLRA to 27(HEX) for disabling LTFT adaptation,but it`s seems not helping at all its still -25% STFT at idle. Any idea how to make it eaven bit better?



 

IMHO the easiest way to make the engine flawless is as follows.
Change the FPR to 4 bar and return back to 310cc black injectors (0280156061).
You get 355cc Q-stat that will be enough to tune engine up to 210PS.
If you want get more power on "everyday car" with minimum rebuilt
use right versions of injectors (from TT 225 PS using 4 bar FP) and more effective intercooler with K04 turbo.

I have already tried to put 4bar FPR with 310cc a while ago before I bought 470cc and was also not much better. Not sure if it's was bad FPR or fuel pump but wasn't working properly with 4bar FPR.

So after that I decided to do a littlel upgrade
70mm downpipe
FMIC
470cc
Turbo form my Golf GTI mk5 with minor mods to fit in A4 1.8 t
and new fuel pump. It's gave me a little more power instead of old K03.

The only difference I can feel with 470cc that this car runs much better through RPM < 4500 at WOT, only idle and and part throttle behave jearcking coz of lot STFT adaptation. I really don't know how to get that in control.  

How about TEMIN? I didn't touch this map, and IIRC it's 0.8989.
Should I try to lower it?

In short. Use the right type of injectors.
Big physical hardware differences cannot be compensated by software tricks.
That's all...
ps: Have you yet figured out why they sold you the Opel injectors so cheaply?  ;D
Just compare the manifold geometry of the Z20LER engine and your 1.8T

 :D :D :D Yes I did, that's has been followed through my mind too as I have started to face this nightmare during calibration

I'm familiar that this injectors coming form Opel. So I thought it's probably gonna work with some adjustments by tweaking and tricking some maps, but on fortunately I was completely wrong about. But anyway I'm gonna try some more adjustment at weekend again, will see if I can do it to get STFT at least to -10%. Will keep this thread update if I will make any progress.

Thank you for clearfaction gremlin that's good to know. At least now I know that's it's not a tune related by myself(perhaps it is form anther perspective of view), I'm not a tuner and been far form it, and I'm just trying to do some stuff for my self during reading and re-reading very useful content on this great forum and S4 Wiki.

FYI, TMIN and TVUB can be viewed in the Opel ME7.6.2 firmware. TMIN is the same = 0.9ms
TVUB has very little difference. See picture.
You can also view the differenceis between VAG and Opel used injectors.
Not only spray. Note the difference in Q-dyn.

I don't have file from Opel, but what about KRKTE in that file, are the offset factors are same for KRKTE and TVUB between this different ECUs. 


Want Q-dyn stands for? What does it mean? Sorry man I ask you perhaps a lot of questions, but I really like to understand it better.

You can't direct compare KRKTE because the value is ECU hardware (MCU clock) dependent.
TVUB from Opel you can use as is.

BTW did you correct FRLFSDP map?



Its injector performance at relative short IDC values ​​- grams of fuel per 1000 pulses of 2.5 ms duration at nominal FP.
Characterizes the linearity of the injector operation, which depends on its mechanical design.

Yes i set FRLFSDP to 1 for non-returnless fuel system after conversion.

Thanks mate to make this stuff more clear for me. I really appreciate it your efforts, times and patience explaining such stuff for me.   ;)