Variable cam timing for performance applications
03-03-2007, 01:11 AM
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Variable cam timing for performance applications Has anyone explored the potential of using the variable cam timing system on a tuned application. What does the thing do anyway, advance the cam timing with RPM? can the amount of cam timing be changed?
I am kind of hoping that it will be possible to get a broader torque curve from a more agressive cam, but I am not sure how much use changing the timing of the intake and exhaust together is. I can see that changing the LCA would be a great thing.
I am kind of hoping that it will be possible to get a broader torque curve from a more agressive cam, but I am not sure how much use changing the timing of the intake and exhaust together is. I can see that changing the LCA would be a great thing.
03-03-2007, 09:38 AM
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The only thing that can be done with the variable valve timing (VVT) offered today for the Gen IV engines is to advance or retard the cam and thus broaden the torque range a bit. The new Gen V twin cam pushrod engine that is being discussed on occasion could have separate cam phasers and thus change the lobe separation angle (LSA) and/or advance the intake or exhaust cams separately or together.
In a road racing application with short radius hairpin turns and longer straights, etc. the twin cam with VVT would hold some advantages if the complexity did not cause durability and reliability problems. However for drag racing or power boat racing where the RPM range is pretty narrow for power, I don't think that VVT (current day or future versions) is that valuable.
If the more aggressive cam you are referring to is for a daily driver/occasional drag car, and the car is a dog as a daily driver, the cam is too big and you need to go more conservative in the cam selection. VVT, if you could adapt it to your current engine would only fine-tune the valve timing a little and not really help this kind of issue with a big cam.
Hope that this helps.
Steve
In a road racing application with short radius hairpin turns and longer straights, etc. the twin cam with VVT would hold some advantages if the complexity did not cause durability and reliability problems. However for drag racing or power boat racing where the RPM range is pretty narrow for power, I don't think that VVT (current day or future versions) is that valuable.
If the more aggressive cam you are referring to is for a daily driver/occasional drag car, and the car is a dog as a daily driver, the cam is too big and you need to go more conservative in the cam selection. VVT, if you could adapt it to your current engine would only fine-tune the valve timing a little and not really help this kind of issue with a big cam.
Hope that this helps.
Steve
