After my cam install my fuel trims were way off. I am able to get my LTFT Lo to 0.4% which is good. However my Mids are at -12.5% all the time. Does this mean I need to increase latency in the 11.72-14.06 range or decrease it? Will doing that then affect my Lo?

I have FIC 950s and used the numbers provided in the super merge thread. On stock cams it worked out fine but with the S2 neither are really helping.

 

im quickly answering here:


Latency affects more low than mid
Scaling affect both near the same

You will need to raise scaling until LTFT mid is 0, but your LTFT low will also raise. Then you will have to reduce latency to get your LTFT low near 0.

 

Interested to see what you come up with as I am installing S2's and have the same injectors on E85. If I beat you to it I'll post my results for you.

 

Speed Density or MAF?

 

MAF and I am having no luck. When i switch to SD car runs insanely lean. I just reset the battery and going to drive around for a while after raising my scaling.

 

Turn off LTFT all together and only worry about the STFT.

 

How do I do that? Is that done by just disabling the Rear o2 or is there a bit? I thought STFT was based on LTFT?

 

Open loop load tables

 

Doesn't that also disable STFT? It sounds like he is just suggesting eliminating LTFT and not STFT. I could be wrong.....

 

FAA in hex is 0x56D8.... its periphery bit 1 if you have the binary version.

You can tune the car entirely in open loop. I would start with disabling the LTFT and see what the STFT does. If its alreadt good, finish tuning the WOT and Bob's yer Uncle.

 

What would be the disadvantage of leaving LTFT on?

Personally I would try to rescale the injectors (injector size as well as latency) to get things back in line and then if needs be put idle into open loop and set the AFRs where required to get a smooth idle (probably 13.x afr).

 

Look there is like 12 different ways of dialing fuel trims, from easy to simple. Just dial thems with any method pointed here, or search in the forums there is plenty answers about it.

 

LTFT are 3 more things that people worry about that dont matter, are off from the factory, and take 30 minutes to change. They need reset every time you make a scaling change to make sure that the 30 minute window can be bypassed. They dont realistically help the car drive or idle and in the case of some cars (i.e. X) complicate the WOT tuning.

S2s and idle on MAF in an VIII definitely prefer rich for the smoothest idle.

 

in for knowledge

 

seems odd that your mid trim would change so much with just cams. was anything else changed or altered? i kinda wonder whether you have a massive air leak.