One thing that really made a difference was to concentrate on the Cruise LTFT getting to +-2% and let the idle be the one that is slightly more off. You can also try changing the scaling of the injectors one notch richer or leaner and possibly get better results than playing all day with latencies.

One thing that I didn't think was necessary was to reset the battery for 30 sec after making a change to latency or scaling figuring it would just drift to where it should be eventually. Well, I couldn't have been more wrong!

Settings that had me at -1 Cruise LTFT and -10 idle LTFT ended up being perfect once I reset the battery and let it find the trims without any previous knowledge of leaner settings. Ever time I've checked now I'm at +-1 Cruise LTFT and -1 to -3 Idle LTFT which is working out great. I also have the car dialed in to run 11.5 AFR's with the LTFT crossover set to 600 Hz, effectively keeping any LTFT adjustments from effecting WOT operation. Likely setting the crossover point anywhere between 300 and 600 Hz will work quite well.

 

I have just a Test-Pipe and a conservative self-tune. Should I adjust these injector settings?

While idleing in garage for 10 minutes I ve got

LTFT Idle: 2.73 -> 5.66 -> 5.47
Then, I turned the a/c on, and after some minutes I have got 4.29. After another couple of minutes, I have got 1.37.

LTFT Cruise: 6.25 all the time (is this related to the fact I had not moved the car?)

According to the tips above, I should adjust the injector settings, but I am not sure about this, since I am still using stock injectors. What difference could this adjustments translate to? More performance? Smoother idle?

Actually, I dont know how to log these parameters? Should I start the engine and let the car idleing for x minutes and take note of the LTFT Idle? What about the LTFT Cruise?

Thank you,
Best regards,
Ziki

 

You'll want to actually drive the car to get the cruise LTFT's to reach the correct values. Stock injectors shouldn't need to be adjusted that far but if you are slightly positive LTFT's (it's adding fuel because it's lean) then adjusting the injector scaling one notch lower will richen the trims across the board. I say notch because it rounds to the nearest accepted value when you alter the injectot scaling value.

Changing the injector scaling settings richer will bring your positive fuel trims closer to zero and make your WOT operation more consistant since the LTFT adjusts the WOT fueling by defualt.

You really need to do some normal drive cycles to get a baseline of what Idle and Cruise LTFT's the car is balancing out at. If you make any changes you must reset the battery to zero out the trims or you could get unpredictable results.

 

sub'd

 

Try these:

Scaling 860

5.952
5.16
2.712
1.776
1.416
1.056
0.792

 

MotionLab Tuning 800cc injectors
LTFT_Idle -0.19
LTFT_Cruise -1.36
770
5.304
5.304
2.808
1.992
1.608
1.200
0.672

 

So I got a new set of scaling/latencies for the DW1000's and they seem to work REALLY well once I got the MAF scaling completed.

E85 Scaling: 636
Latencies:
3.504
2.184
1.944
1.704
1.464
1.104
0.84

My LTFT Idle is 0.5% and LTFT Cruise bounces between 0.3% and 1.5%.


ETA: Apparently these latencies are good for the 800's as well, but YMMV, etc.

 

Anything for id2000 injectors

 

what's the correct voltage number at idle?
Thankss...

 

Most of your injector time will be spent at 14.07, bumps into 16.41, and less so into 11.72.

 

I realy do not know what I am doing, I didn't even know what injector lattency was 4 days ago (still not sure) but here is what I ended up with:

DW 1000cc, E85
Scaler = 562

4.69v = 6.12
7.03v = 5.26
9.38v = 3.60
11.72v = 1.97
14.07v = 1.46
16.41v = 1.18
18.68v = 0.89

LTFT idle = +1.4
LTFT cruise = 0.00

 

Pretty sure this is the most confused I have ever been in my life.

For the same injectors (DW 1000's) we have pump gas values ranging from 713 to 886 and for DW 800's 696 to 750!!! This means some people are running 1000cc injectors that are scaled lower than other people are running 800cc injectors!

I may be retarded here, but it seems to me if the stock injectors are 550cc and they are scaled at 532 this gives a "fudge factor" of .967 so a 1000cc injector should be scaled at 967 and an 800cc injector should be scaled at 774. From there we make adjustments based on observed A/F ratio on your wide band O2 sensor, and the effects on your LTFT. The Cobb tuning scaling for 800cc injectors at 750 is pretty close to the 774 I came up with using a bit of math.

Now, on the latencies, doesn't this information come from the producer of the injectors?

Thanks,

Keith

 

stock injectors are 600cc...

but dont worry about the scaling, as long as your trims are in check its ok..

some people have leaks, some people have incorrectly scaled MAF, some injectors flow more than they are rated etc etc...

 

You are not retarded. Keep in mind that a persons intake (MAF) calibration effects fueling, so depending on whether people are properly calibrating their MAF, it will effect their injector settings. Also, DW sais for gasoline, their scaling on the 1000's is 975. Cobb likes to run 886 on the same injectors. I ran both for a settings on my car for a while, and both were fine, but I ran a slightly different maf calibration for each setting. Cobb likes to use a multiplication factor of around .72 when they convert from 93 octane to E85. Other people like to use .70.

Add to this that things like air filters, temperature, humidity, fuel quality, etc all effect fueling, and you will understand the seemingly large variance in injector settings.

What is most important is the end result, ie fuel trims in the correct range of +/- 5% or so, and WOT fueling at full boost being at the desired AFR's.

 

Good thread. Will come in handy when tuning my buddies X