tephra man your a PIMP!!! Thanks for all your hard work man!

 

Good to know I'm not the only one fluctuating 2% or 3% on the same day/same fuel etc. It's possible that driving at 75 mph for a bit will yield different LTFT's from driving at 60 mph based on numerous factors, I'll have to do more testing to see if increasing the timing is reallly effecting the trims.

 

guys, why can't we run the car in the open loop all the time ?

Also we have 7 latencies, which one should I adjust to correct STFT and LTFT ?

 

Something about it knocking like crazy at idle. Forgot where I read this at... hmmmm...

 

I usually adjust all of them by a percentage but the important ones are the 12 - 14v range since that is where your car is running assuming it's healthy.

As for runing all the time in Open Loop it can be done but you have to tune the AFR's for all kinds of part throttle and cruise combinations below around 100% load. Get it wrong and you are going to have some drivability problems. I know when I tried it for a lean burn cruise it wasn't just going to be an on/off switch but I would have to tune the car to behave like it did with O2 sensor feedback starting on the rich side and working my way leaner.

 

Anyone have any clue how a phenomenon like this is happening.

I-LTFT +2%
C-LTFT -7.5%

I have DW800cc Injectors. This is what I had for LAT/Scale


Should the formula for scaling be (800CC x 532CC) / 550cc OR 600cc???

Thanks!!!

 

That's way off from what I have. I've attached my settings that I found were alot better than what DW supplied with the injectors. I do have cams and different intake but it shouldn't be too far off for dialing in.

I've given these settings to a number of people and so far, no complaints.

 

Thanks, I give these numbers a test.

I will have to dial in my injectors with the stock intake, and then add the intake and MAF settings from COBB and dial that in.

 

Bringing this thread back from the dead. NJ, how are Evo IX's affected by intakes, LTFT, AFR etc. I read your post on the funky AFRs and I've noticed that my AFR richens a whole point from 3500-6000rpms a few days after a tune or flash. To counter this should I adjust injector scaling, latency, MAF scaling, or just disable leanspool all together? I'm just running a open element intake, TBE, MBC and a self tune with ecuflash.

 

what was your LTFT (mid) when you had it tuned?

like its 9% now - what was it when you tuned it?

Your trims are both about 9% - so you can reduce your injector scaling 1 jump and then retest..

DONT FORGET YOUR FUEL MAP ALSO REQUIRES CHANGES.. so get a WB

 

You have two ways of doing this:

1. Lower the injector scaling from 513 to 472. That will lower BOTH the idle and cruise trim equally and should bring them as close to zero as possible. The downside is that you must re-do your AFR cruve. Lowring the scaling makes the car run richer and you must lean her out in the fuel map. That is the approach that I took.

2. Add latency in 12-19v range. Adding 0.05-0.07ms should bring the mid-trim down to 3-4% and that should negate its impact on the AFR during WOT operation. The idle trim will go down further and might become negative. But the idle trim is not adding fuel during WOT, it is the mid-trim that is the culprit. The upside to this is that you do not have to redo your fuel map; latency changes do not have an impact on the fuel map.

 

Good info, I knew the Injector Scaling effected the WOT maps but now it makes sense that the latency never effected them since they never seemed to alter my tune.

I ended up using the LTFT disable coding to lower the crossover threshold of where LTFT is not added into WOT operation and I ended up bringing my Injector Scaling down a notch to make everything richer again so that I could tweak it a bit starting from the richer side of things. Right now it seems to be working great and the AFR's are really stable.

 

nj1266 what do you think of using a lower crossover threashold to high LTFT's to negate the impact of the mid LTFT adding fuel?

 

Tephra says that he got the code for the X from the 8/9. So if it works on the 8/9, then you might as well try it. That will eliminate the impact of the cruise trim at WOT.

I have not tried it on my 9, so I do not know if the code will work.

 

Thanks for providing all these pics of all parts of your car. They are good and very helpful fir selecting a new car.