Think this is too much cruise advance?

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Sep 21, 2008 | 07:04 PM
  #1  
It seems to like it.. Only knock counts I got were on startup.

My closed TPS spark is 25 degrees.

WOT tapers off to 26 degrees. Second scan is a 35-55mph WOT burst. Only made about 3-4psi of boost but it felt good. I don't want to spin it much past 4500 until I get the VE dialed in for good.

-- Joe

Think this is too much cruise advance?-cruise-spark.jpg   Think this is too much cruise advance?-accel.jpg  

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Sep 22, 2008 | 08:00 AM
  #2  
Re: Think this is too much cruise advance?
I'm running the same amount of advance at cruise, but I leaned it out to 15.5:1 to save on gas as well. What is your desired AFR for WOT? Am I reading correctly that you had a 8.5:1 ratio?
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Sep 22, 2008 | 08:49 AM
  #3  
Re: Think this is too much cruise advance?
Quote: I'm running the same amount of advance at cruise, but I leaned it out to 15.5:1 to save on gas as well. What is your desired AFR for WOT? Am I reading correctly that you had a 8.5:1 ratio?
Desired? Who knows. I'm running boost, so it has no idea how much air is in the mix. I have my PE fuel set pretty high to enrich the boost. If you look at the 02 voltage I'd say it's in the 11s some where but with a narrow band who knows for certain.

-- Joe
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Sep 22, 2008 | 09:40 AM
  #4  
Re: Think this is too much cruise advance?
Looks reasonable to me.

I'm at about 40 degrees in a 2k cruise, without any highway mode spark enabled. Now, I'll try about 44 for LV8 64 and rpm >= 2k and see how it goes.
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Sep 22, 2008 | 10:00 AM
  #5  
Re: Think this is too much cruise advance?
Any plans for a wideband? You probably are already aware of the benefits, especially w/ boost. Also, what size injectors are you running?
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Sep 22, 2008 | 11:42 AM
  #6  
Re: Think this is too much cruise advance?
Quote: Any plans for a wideband? You probably are already aware of the benefits, especially w/ boost. Also, what size injectors are you running?
I'm running 30# injectors and 50psi at about 16hg.

I'm on the fence about a wideband.. I used to have one. When tuning a lot of guys get stuck on trying to dial in a specific AFR and lose sight of what makes the most power. There are benefits I'm sure and I may find myself putting one on in the future.

-- Joe
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Sep 25, 2008 | 08:41 PM
  #7  
Re: Think this is too much cruise advance?
At 30-40 kPa, it's extremely hard to get knock, so tuning by knock at that point is futile. Tuning by feel is also flaky at such light loads. A chassis or engine dyno could do it well, but what's the benefit. A little too much spark there won't hurt anything other than a little economy, same for too little. If it were me, I'd just stick to something near stock (or something stock with similar parts) and leave it alone. There's no competition for who can run the most spark advance. In fact, IF less is better, then your combo efficiency is better.
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