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Old 05-19-2009, 07:34 PM   #1
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Default Stupid knock

Boost it set at 18.5 psi and I keep getting knock and a hesitation at high rpm's. AFR's are low 11s with 93 fuel. I started with the top map below before upping the boost and had no knock. Now with the higher boost I have the knock. I changed the spark to what you see in the lower map and still have knock. Anyone have any ideas besides lowering boost?
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Old 05-19-2009, 07:51 PM   #2
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18.5 psi is what 220kpa? the timing's barely/not changed at that level...

Try a more drastic cull of timing, it's easier to control a fire than put it out
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Old 05-19-2009, 09:19 PM   #3
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16* is around what most us stockers run at 12-14psi, just fwiw.
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Old 05-19-2009, 10:00 PM   #4
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So I should pull even more spark?
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Old 05-19-2009, 10:41 PM   #5
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pull until u stop knocking to see where ur at. Do you have knocksensems?
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Old 05-20-2009, 06:48 AM   #6
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19psi on pump gas might just be too much.
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Old 05-20-2009, 07:25 AM   #7
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Time for WI =)
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Old 05-20-2009, 08:48 AM   #8
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Quote:
Originally Posted by Savington View Post
19psi on pump gas might just be too much.
Quote:
Originally Posted by Fireindc View Post
Time for WI =)


That's what I was afraid of because even with a spark map close to DIY's base map I was getting knock.

I guess I'll just have to settle for 16 psi.
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Old 05-20-2009, 10:19 AM   #9
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or run race gas or WI.
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Old 05-20-2009, 10:42 AM   #10
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Bad gas maybe? You are on the east coast so it should be a problem.

If you are getting knock on the DIY map then it might be something worse. Are you sure your mechanical timing is correct?

The DIY map is so damn conservative, I have no idea how you can develop knock on it.
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Old 05-20-2009, 10:58 AM   #11
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try a gallon of toulene when you get to about half a tank. stuff works awesome on my MSM
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Old 05-20-2009, 11:05 AM   #12
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Quote:
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try a gallon of toulene when you get to about half a tank. stuff works awesome on my MSM
I really doubt that will work, we're talking 18-19 psi here.
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