07GTS
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- VEGTS BUILT BLOWN E85
yea u can use a little overlap but the way that works is as soon as the intake valve is cracked and exhaust is open it goes straight out as the intake valve has pressure on it just waiting to flow in, BUT overlap with the PD blower will increase torque lower in the rpm if u want that but then limits it up top,You can use a little overlap on PD but you shift the EVC and IVO closer to the EVO event. Boost bleed off is not as much of a concern as some think.
Also most cam companies run way too much lift on the exhaust lobes.
may last cam had massive torque that peaked at 3800rpm (5 deg overlap at .050 or 57 deg at .006) and then fell off fast but HP kept going up till 6700rpm, what a wider LSA does too is flatten the torque curve and place more up top so i want to use all that torque i had at 3800 and push it further up so it can be multiplied into HP, can also use a little overlap to send some fuel over the exhaust valve to help cool it, and less overlap can also help with knock resistance as it dosnt disrupt the intake charge with left over exhaust,
yea exhaust lift with the smaller valve just isnt needed past a curtain point it does nothing, better to have a longer duration and lower lift then the intake, worst part about building an engine is hoping all the parts u choose work together when its done