How lean is safe

[ken sampson]

I wanted to see how lean everyone is running the highly modified setups.
When under heavy boost I am at about 11:5 is this to rich? I have been told you can lean out to about 12:5 is this safe? My tuner keeps warning me when I as him to lean it out a little more.

 

[Elite]

You are FI right? Stay below 12:1, somewhere between the 11.5 and 11.8-9 is where you'll end up safely(in regards to A/F.. the rest of the tune is extremely important obviously). 11:5 isn't "to" rich, it is fine, but you may have a tiny bit of room left. But in the end, I'd listen to your personal tuner, whatever they are comfortable with.. stay there.

 

[BadCarma]

You are FI right? Stay below 12:1, somewhere between the 11.5 and 11.8-9 is where you'll end up safely(in regards to A/F.. the rest of the tune is extremely important obviously). 11:5 isn't "to" rich, it is fine, but you may have a tiny bit of room left. But in the end, I'd listen to your personal tuner, whatever they are comfortable with.. stay there.

I agree with elite, you could in theory tune it closer to the mean end of the a/f ratio but if you are not a tuner and your car is certainly in the correct A/F for forced I would stay with what your tuner wants. what he wants is for you to have a margin of safety, your not racing it on the track in competition and that is where we take the ratio to the edge and those engines get torn down after a set amount of runs or laps decided by the tuner- engine builder

best regards david
ps enjoy!

 

[nsxtcy85]

11.5 is not to rich but it could probably benifit from more power and better fuel economy around 12 to 12.5 I personally dont think thats too lean unless running high boost. anything under 10psi I am personally going to run 12-12.5 myself.