safc II Lo throttle tuning

89supracrazy

New Member
Oct 31, 2009
317
0
0
wise
I am trying to tune lo throttle with the safc II and at idle my vf reading is 4.75. The chart I read says 5v lean and 0v rich learned value. I am on the stock fuel pump and I do not have a afpr. I have to put the lo throttle at 18+ for it to get in the 2 range and then it jumps from 1 to 2. Do I need a afpr to fine tune and is my stock fuel pump shot with that kind of numbers.


mods
lex afm
550 injectors
safc II
 
Last edited:

bountykilla0118

In Pursuit of 500rwhp
Jul 16, 2005
1,088
0
36
39
Atlanta GA
Since you come off as a guy that is new to tuning. I would ..... get a fuel pressure regulator and tune with fuel pressure first and then do some fine tuning with the SAFC. If you find your self taking out more than 25% I would drop my base timing down a little until you can get to a dyno, even though some think our timing map is a bit conservative. But I never seen the actual timing map so I cant say for sure.
 

89supracrazy

New Member
Oct 31, 2009
317
0
0
wise
Yeah. Thanks for the advice. I have been doing some reading and you are right I need a fpr to steady my VF reading. I noticed that I am fighting the computer. Another question can I tune with VF with wot. I have read some people say yes and some say no. I thought the car went in to open loop which would read ovolts on my VF reading. I'm I right on this. Do I need to get a wideband anyway.
 

IwantMKIII

WVU MAEngineering
Jun 12, 2007
2,477
0
0
Perkasie, PA
^As far as my understanding goes its useless to try to tune at WOT with VF as it enters open loop. Tuning low/part throttle is for the most part useless except maybe idle i've noticed it helps. Other than that thought the computer will fight the safc settings the entire way until you go (IIRC) about 70% thottle; i believe the open loop WOT is slightly different on every car. Also, don't get above 20 correction as from previous threads some users suggest it alters timing maps which is not safe.