I was just wondering what the point of view of experienced tuners is on A/F ratio with 12.0. I just had my car tuned and it made good numbers (470 hp w 460 tq) but the A/F curve was at or just above the 12.0 mark...I dont want to hurt the motor, but the guy that tuned it is reputable in the cobra tuning community.:??:
Flirting with a 12.0 A/F ratio
- Thread starter j2schill
- Start date
I am no expert, but from what I've read, you won't pick up much more power from leaning it out that much, you get more power from timing... I would say drop your a/f down a notch... at most you will lose 5hp?(someone care to verify)... i'd rather be safe than sorry...on the other hand, every car is different, but I would stick with the norm...
Was he using a tail pipe sniffer, or was he measuring the A/F through a welded in bung in the exhaust BEFORE the cats? If it was a tail pipe sniffer you might be ok. Your best bet is to install your own wideband A/F gauge and measure it yourself. 12/1 is a little leaner that I'd want to go on a boosted engine.
Edit: maybe you can add 2-4% more fuel yourself with your handheld tuner. You'll maybe lose 5-10HP.
Edit: maybe you can add 2-4% more fuel yourself with your handheld tuner. You'll maybe lose 5-10HP.
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^^^yeah what he said it will usually read about .5 points leaner with the tailpipe sniffers. I blew my engine with a 12.0-12.1. Your air to fuel may change a few tenths in cold vs warm weather also.
how did you blow your motor?..high speed run?
It was the O2 sensor under the car..so it was pretty exact.
It was the O2 sensor under the car..so it was pretty exact.
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My tuner said 12.0 was MAX for a tailpipe sniffer. But again, that all depends on the A/F being matched properly with timing and Octane.
:beer:
:beer:
Ran it lean at 12.0-12.1.....pulling the engine in a few weeks and will find out what piston/s it was. I would back it down to the mid to high 11's just to be safe you don't want to be in the same boat I am in....
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12.0-12.1 isn't lean enough where it should be the cause of the motor going south. There had to be other variables involved. Most tuners like to be safe and go with 11.5-11.8, what tuner wants it out there that they've blown motors? In reality 12.0-12.1 isn't bad as long as your not trying to run a ton of timing and have enough fuel to supply the motor.
I just checked your graph from your other post, it looks like your are under 12 for some of those runs, and over for others. Its hard to tell though without a closeup. Cant hurt to ask him, maybe because of the NOS?
True. I don't remember what the timing was set at, think 19, but if I had to do it all over again, which I have to I would feel more comfortable with 11.5 A/F that way when a variable I can not control such as weather, and bad gas does happen it will still be safe.
During the summer it was at a solid 11.8 A/F and would guess the car was making on the range of 600 rwhp.
2 of the runs are with nitrous. and i have a wet kit. so the fuel solenoid addition makes it run in the low to mid 11's. I actually emailed my tuner and he said that he added a little more fuel to the mix after the first couple runs. so it doesnt show high 11's, but i dont think he would be making it up. Im sure its safe now. I really didnt feel like paying a pretty penny for more tuning with this setup until i add something else.
I would say back it down, unless running on race gas or meth injection. 12.5:1 is max for me with meth injection, the cool charge that meth offers helps a lot with detonation, but if your just on pump gas I would say keep it from 11.5-11.8.
I run 7.804 A/F.
Damn E85 guys...
to be safe id want to be in the 11.5-11.8 range..
and you also put fuel in the tank every time you drive it:banana:
For fuel this good, I'll kindly pay $2 per gallon and stop by to see the friendly fuel attendent! :thumbsup:
Do you have a trailer hitch on the car so you can pull an external fuel cell behind you?:rolling:
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