What is the best A/F to have when tuning for FI where should the timing be? I realize there are variances but, I have a sleeved built motor, cams, porting, greddy's w/60-1 upgrade, FCon etc etc. I remember seeing a thread where Audible Mayhem said that you will make the most power at around 12.8 and that timing should be +2 degrees across the entire map. Tuners jump in. I'll have a low boost 11-12 psi and a high boost map both pump gas.

 

You should probably consult your tuner for that question. There's about 1 million variances that you tune for, no one can really answer that question and it's all out of preference for power numbers etc. Some tuners tune to 10.8:1 some to 11.5 some to 12:1 all of that is directly correlated to the atmosphere its tuned in and most importantly the gas you plan on running (c16 race gas or california **** fuel 91 octane?). A car that runs at 3000ft in 115 degree heat will command alot less timing and will knock alot faster then a car that runs at sea level at 80 degrees.

 

Yeah but, I was trying to get a general consensus on what is acceptable. I'll be running pump + methanol system. I think 10.8 is too rich but, I don't know so, I wanted everyones opinion.

 

10.8 to 1 is way to rich. 11.8 to 11.5 is my tune with approx 400-420wwhp. but

 

hey man, i was making a very general statement about tuning a NA car with that graph.


not even close with FI, values are very very different...

 

Gotcha. What are good target A/Fs then.

 

with your build you really should consult a real tuner, thats alot of money to learn to tune on.

 

Yeah, i'm not tuning it myself. I have an Fcon installed and i'd like to have a target A/F to go with. Some tune rich and others lean. I want to know whats a good in between.

 

Since you have the Fcon you are obviously going to go to a tuner that is HKS authorized it seems you don't know much about tuning so go to him with your questions, there is nothing more annoying than someone that goes in with tuning advice they have read on the forums.

 

actually there is, its someone who blew their motor by going in and "tuning" with tuning advice they have read on the forums...

 

Valid point

 

Where it makes the most power or knocks - whichever comes first. Then back it off a little for a margin of safety. Like the others said, use a reputable tuner.