Quote:
Originally Posted by Meph
Ive tried out driving with +4 and +4 and did seem to notice a little bit mroe torque down low, nothing very substantial. As I advanced the intake cam, that controls engine timing I will need to recalibrate my ignition timing aswell.
Ive been reading differnt threads on here and opnions seem devided over advancing or retarding cams to get best results. On a stock car with Variable Valve Timing I believe they advance the exhaust cam in low rpm and retard it in high rpm?
Ignoring the intake cam, would and advance solely in the exhaust cam result in more torque and theoretically more MPG in the 1500-2200 rpm range of an engine with a redline of 7000. Later variation of my engine had vvt on the exhaust cam.
Thank  |
here info from Honda K24 doc on VTC operation .
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Driving Condition , VTC Control, Description
Light-load = Base Position, For stable combustion the cam angle is retarded, and reduces the entry of exhaust gas into the cylinder.
Medium/high-load = Advance Control, Cam phase angle is controlled to optimize valve timing, improving fuel efficiency and reducing emissions.
High speed = Advance-Base Position, To reduce pumping loss, the intake valve is closed quickly. This gives the air/fuel mixture a charging effect that helps to maximize engine power.
VTC System
The VTC system makes continuous intake valve timing changes based on operating conditions.
Intake valve timing is optimized to allow the engine to produce maximum power.
Cam angle is advanced to obtain the EGR effect and reduce pumping loss. The intake valve is closed quickly to reduce the entry of the air/fuel mixture into the intake
port and improve the charging effect.
The system reduces the cam advance at idle, stabilizes combustion, and reduces engine speed.
If a malfunction occurs, the VTC system control is disabled and the valve timing is fixed at the fully retarded position.
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when you say you advanced +4, +4 , you mean both cams 4 deg .
I think it depends on the cam timing as to what can be improved when altering just 1 cam .