Timing and air/fuel

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calisonic

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This may be a dumb question but, without having any form of forced induction or nitrous, would there be any advantage to manually adjusting the spark advance at various rpms and WOT air fuel ratio with a tuner? Isnt it true that if you use 93 octane you can get a little more power by adjusting these things? Ive got an X3 and am curious about these options.
Thanks!
 
Yes it is all true. But you need to monitor how much adjusting you are doing so that you don't put the engine in harms way thru too much of a lean condition or detonation. I think that Driller is well on his way to doing data logging etc at the track to identify positive parameter imputs, and of coarse there are other mail order tunes from Lonnie and others.
You can see that Doug and Driller are well into logging.

http://www.lincolnsofdistinction.org/vbulletin/showthread.php?t=29228
 
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Thanks Roadboss, Lonnie did put a tune on it when I bought it, unfortunately I managed to change those setting without realizing it till it was too late. :rolleyes: And can't really fork out $50 for a new on at the moment.

Could we say an advance of one degree (only allows me one or two +/-) and an air fuel setting one or two ticks higher than stock would be safe? I have tried these setting and honestly didn't notice any change in performance so I'm tempted to go higher, but of course I won't unless I know it's safe to do so.
 
calisonic said:
Could we say an advance of one degree (only allows me one or two +/-) and an air fuel setting one or two ticks higher than stock would be safe?
Click to expand...

Before really doing much with A/F ratios, you really need a good quality wide-band O2 meter.

That being said, you can easily change WOT timing and fuel. I doubt one or two degrees added timing would be unsafe.
 
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Good to know. What does "wide band" mean anyway?
 
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Stock O2 sensors are 'narrow band' and are meant to read A/F ratios at or near 'stoic' of 14.7 and basically signal either rich or lean when above or below the stoic value.

"Wide band" meters however will read a linear value across the range giving an actual quantity reading for what ever the A/F ratio may be. This allows you to tune to a specific and safe value.
 
Without a WBO2 and some data logging, you're playing with fire. :eek:

Leave it alone.
 
DLF said:
Without a WBO2 and some data logging, you're playing with fire. :eek:

Leave it alone.
Click to expand...

+1...being that you didn't notice any performance increase, it is likely that your knock sensors pulled the timing adjustment you made.

Btw, Lonnie keeps a backup of customer tunes...I think. Ask him if he can email you the tune.
 
Yeah, you generally mat it in first gear and break the wheels loose bringing the RPMs up really fast. If its going to rattle, it will.
 
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