Advance timing (ground in)
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From: Fuquay-Varina, NC
Advance timing (ground in) What difference would I expect going from a 2 degree advance to a 4 degree advance? Would it dramatically reduce top end going to 4?
advance moves the valve opening/closing events toward the exhaust side of top dead center. this tends to give lower peaks for torque/HP. More directly, the 2 deg would shift when the intake valve would close, the most important factor in peak position relative to RPM. this would also affect dynamic compression.
2 deg, according to the knowledge that I have seen on the boards, lowers these peaks around 100 rpm.
not a dramatic change, probably inperceptible.
2 deg, according to the knowledge that I have seen on the boards, lowers these peaks around 100 rpm.
not a dramatic change, probably inperceptible.
I have a small cam on a 115 LSA. They ground in 5* of advance to pull the curve down and the cam peaks at about 5,900 RPM whereas normally a 115 LSA would have a higher peak RPM.
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From: BFE
Originally Posted by danf1000
advance moves the valve opening/closing events toward the exhaust side of top dead center. this tends to give lower peaks for torque/HP. More directly, the 2 deg would shift when the intake valve would close, the most important factor in peak position relative to RPM. this would also affect dynamic compression.
2 deg, according to the knowledge that I have seen on the boards, lowers these peaks around 100 rpm.
not a dramatic change, probably inperceptible.
2 deg, according to the knowledge that I have seen on the boards, lowers these peaks around 100 rpm.
not a dramatic change, probably inperceptible.
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Joined: Mar 2004
Posts: 14,620
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From: BFE
If you want to bring the band down a bit that could mean 100>200 rpm lower.
Like the difference between shifting at 6700 or 6500, trq will peak a bit sooner too cam will not carry as far after peak
Like the difference between shifting at 6700 or 6500, trq will peak a bit sooner too cam will not carry as far after peak
