QUICK - HOW DO YOU LOG LT FUEL TRIM? AND ST?

B6/7 S4/RS4
#1

thanks

#2

Real rough…from memory:

Engine 01
Measuring block 032

Then go into Engine 02 (under “chassis” I think)
Measuring block 032

If you can’t find it I’ll take a look tomorrow and give you step by step details. Or I’ll just make a quick vid and post it.

#3

TYPING IN CAPS LIKE A NOOBZIE

I have no idea

#4

Engine 01
Measuring block 032

Measuring block 032 is a reference block not so much a log block. This should show the Idle and part throttle fuel trim adaptions for each bank. This is the amount of fuel added or subtracted as a average over a fixed calculation over time. They reset as you drive the car but they don’t run when your WOT.

#5

I have no idea how to log the information you are after.

What information are you trying to obtain from the logs? what insight into the engine do these logs provide. sorry for the Q’s not very knowledgeable in this area

#6

Carlos has the info, not really logging as looking at a snap shot of recent history - same stuff I learned when reading through various articles and when I came across Ross Tech’s wiki:

http://wiki.ross-tech.com/wiki/index.php/Fuel_Trim_Info

Lout Jr., some useful information in the link that may help answer some of your questions. In short, it’s a quick way to see if your ECU is adjusting fuel mixture correctly based on what your O2 sensors and MAF is telling it.

#7

This was for my car. We managed to get JHM on the phone and provide all the numbers they wanted so it’s all good. Thanks for the help guys!

#8

i wanted it to stand out so someone would give us a quick response…we were tying to log Axel’s car.

#9

Thanks for the info.

Now that saki said they were trying to log axle’s car it makes more sense. I was confused why he wanted to know that info on a stock car, unless it was for curiosity reasons.

My favorite line from the link was “injectors are in a union, so it is tough to fire them”

So how did the logs look on axle’s car any improvements

#10

I thought you were wanting to know on the RS4, and figured it might be different with the dual ECU situation. But yea, carlos hit it right on the head. I’ve been doing the same for a little while to get the fuel trims dialed in just right.

For anyone else that might need to do this, I was told it’s best to drive around for 15min+ or so prior to grabbing the readout, and the car needs to be at idle.

#11

looked like something is weird going on with the car’s fuelling. Basically something very simple that will be solved. The updated tune already addressed 95% of the problem he was having. Basically it only happened for the first few minutes after the car was started, then everything sorted itself out and the car was perfect after it ‘warmed up’. The 5 minutes will be addressed in a new tune. He’s still on a conservative version of the SC tune, so his car isn’t quite full bore yet. JHM has 12 supercharged cars running already, and this was the only car that this happened on. The problem with the b6/7 is that there are half a dozen different ECU box codes, so they run into the odd weird code once in a while and the odd car has it’s own idiosyncracies, so JHM has to identify the uniqueness of each car and adjust the tune if these idiosyncracies pop up. Most impressive though how they know all this stuff. Makes me shudder thinking about people who play tuner part time. They haven’t a a chance compared to a real professional.

We did a few pulls. The first one was from about 40 mph, and we both started in 3rd, running up to half way through the RPMs left in 4th once you change. He pulled away pretty hard while I just groaned through the gear. Downlow he had way more. He was 2 cars ahead by the end. When we went from higher rpms it was a pretty close. Shitty night to test things as it was raining etc. We’ll do this again when it’s better weather out, and when he’s on the next tune revision.

#12

I was going to reply but when I hit reply, it said two new posts had been added. Saki saved me from having to type all that so thanks :slight_smile: hehe

#13

I’m guessing it’ll be at least two more tunes before they “up” the aggressiveness of the tune. The first tune should be the same conservative one but with the “5 minute” issue resolved and then they’ll look into bumping it up a little. (in other words, get this fixed, however many tunes that may take before doing anything else).

JHM likes to be thorough :slight_smile:

#14

Great stuff, glad your car is almost there axle