full throttle pinging....., wondering...???? |
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full throttle pinging....., wondering...???? |
crash914 |
Oct 4 2005, 06:28 PM
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#1
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its a mystery to me Group: Members Posts: 1,826 Joined: 17-March 03 From: Marriottsville, MD Member No.: 434 Region Association: MidAtlantic Region |
Ok, When ever I go full throttle, I get a lot of pinging....
in first or second, I can full throttle, but have to shift fast to the quick revs. under part throttle, I can spin up to 6500+ with no pinging or problems. I just can't floor it. seems odd to me. my afr is down around 11:1 at full throttle, so I am running plenty rich. I am running 93 octane, might have to add some xylene. I am wondering if my throttle bodies are too large. I don't know if my air fuel meter can pick it up that quick. I really notice it when I am in 5th gear and am pulling from around 2500 to 6500. I do have a spare set of heads that I can get cut... all right here is the specs...103 by 80. .125inch barrel shims gives me around .1" clearance and around 9.7 to 1. megasquirted with twin weber throttle bodies and large injectors... herb |
Jake Raby |
Oct 4 2005, 06:44 PM
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#2
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Engine Surgeon Group: Members Posts: 9,394 Joined: 31-August 03 From: Lost Member No.: 1,095 Region Association: South East States |
John,
We learned that years ago..... Most engines running race fuel with ;less than 11:1 CR don't need it according to the dynamic CR dictated by the camshaft and many other parameters.. I don't run race gas till after 11:1 static CR with my engine designs- the engine makes better power without it.. runningrace gas with an engine that does not have the CR for it increases EGT just like retarded timing and kills efficiency and kills exhaust valves. |
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