Tuning AFC?

[SBstar]

Alright I know these kinds of questions are asked over and over again, but I'm so new to this I want to make sure I'm understanding things a little bit right. My AFC settings right now are with darkside 550's and the rest stock fuel system, will soon be installing a 255lp high pressure pump and aeromotive AFPR, boost for now is at 5-6 psi will be turned up to about 15 psi soon.

Low throttle settings:
1000-1600-2200 are at -7%
2800 is at -6%
3400-6800 are at -10%
7000 at -16%
7600 at -18%
High throttle settings
1000 at 0%
1600-2200 at +3%
2800-5800 at +4%
6400-7000 at +8%

This is how I bought the car and I've only looked through alot of threads and read the instruction manuals, the car idles a little rough but other then that seems to be running ok. I will have a pocketlogger hooked up as soon as it comes in the mail. Thanks for any input on how things look.

By the way what does stft and ltft stand for?

 

[CanadianTSi]

How can you even run 5-6psi?? the lowest the stcok wastegate can go is 10ish.

Also there's no way you need to add fuel with bigger injectors while running crazy low boost...

PS. they stand for Short term fuel trim and long term fuel trim, but since you have a 1g you don't have to worry about those...

 

[SBstar]

Well the boost gauge is reading 5-6 psi when I hit full boost. There is no boost controller so I'm assuming it should be running stock boost, on a 1G that should be around 11 psi shoudn't it? I have a Big 16G turbo so maybe its a different wastegate? I'm going to have the boost controller tomorrow though and I'll be setting it at about 15 psi to start out with. how do the settings look for something like that? Also why do you think i'm running such low boost?

 

[spyderturbo007]

Wow, those are some of the weirdest setting I've seen on an AFC. Before you go jacking up the boost anymore than it is, you need to do a good bit of reading.

As Canadian said, you don't have to worry about STFT & LTFT with a 1g, but you still need to worry about FT"s. 1g's have a low mid and hi fuel trim that need to be balanced through out the low throttle rpm range (actually only up to 3k).

With 550's your low throttle settings are pig rich and that is probably what is resulting in a rough idle....way too much gas.

As for the hi throttle settings.....WOW...going +8 with injectors that are 18% larger than stock just blows my mind.

Questions: If you are saying that your AFTERMARKET boost gauge is reading 5 -6 psi, you need to find out why it isn't working properly. The previous owner probably banjacked the install and you will need to fix that first!


Do this:

1. STEP AWAY FROM THE BOOST CONTROLLER !

2. Fix the boost gauge.

3. Wait until you get your pocketlogger to do anything.

4. Stay out of WOT until you get the logger (with your setting you will probably get rich knock)

5. Read this :

http://www.racingknowledge.org/topic.asp?TOPIC_ID=1011

6. Read #5 again!

After you have taken care of that, post back up any questions you have and we will be happy to help.

 

[SBstar]

Thanks guys, first off I just bought the car so none of this is my doing. I'm just learning this stuff and I want it done right. Thanks for the input.

 

[SBstar]

Alright the boost gauge is hooked up properly according to the VFAQ, it also has rubber type tubing instead of the plastic stuff. And to be honest I only think its boosting that much because the car feels slow. Under boost it feels just about the same as when I'm not boosting. Any ideas or suggestions?

 

[spyderturbo007]

We want to see you do it correctly as well.....

In the end, you should be AROUND the -18% range. EDIT> Provided your 1g is a 5-speed and not an automatic, as automatics had smaller injectors. This will vary from car to car based on the age of sensors, PCV valve condition, brand of fuel injectors, etc. I normally suggest that people with 550's start their tune (lo throttle) around -10 or -12%.

I would like to see you leave your low throttle setting where they are (rich = safe) and stay out of WOT until you get your logger. Then we can dive into tuning. But tuning without a logger is a big

 

[SBstar]

Alright I just hooked up the pocketlogger. I started doing the tuning and when I changed the low throttle %'s I could hear the car acting differently but all the fuel trims stayed at 118% except the O2 trim 100% full time. I checked diagnotics and it said I had an airflow sensor error. I supose that means I have to replace the mafs, which is probably causing my tuning problems right? Could that cause my boost problems as well? I'm getting a boost leak tester and I'm going to see if thats my boost problem as well. Thanks

 

[drag97GSX]

Not to hijack the thread, but if someone does NOT have a datalogger then they should wait to install the SAFC II until they do have a datalogger? Is that what I understand? Thanks.

 

[spyderturbo007]

If you are on the stock injectors then go ahead and install the SAFC-II. It won't hurt anything, just leave all the setting zeroed out and enjoy the pretty blue display.

If you are going to install the SAFC-II and larger injectors then yes, it is HIGHLY recommended that you have a logger. Tuning with your "butt dyno" is never a good idea.