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Turbo N/A Cam Question

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I've got a N42/N42 motor I initially built naturally aspirated- +1mm flat tops, ported head and a Delta grind 270/280 .464" cam (don't remember LSA).  Originally had it at 10:1 CR but wasn't happy with performance so got a Cometic gasket that brought it down to 9:1 and put a turbo on it (stock boost, 6-7psi).  With SDS fuel/ignition and Methanol Injection, I can almost keep detonation at bay. 


My question is: If I switch to a turbo cam (stock turbo cam for now), would I be more likely to detonate or safer?  With less overlap, would that lead to increased cylinder pressure making it more prone to detonation?  Or would less exhaust gas reversion lead to cooler cylinders?  What other physics are at play?


Thanks for any input!



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Going to the turbo cam will increase your detonation propensity. Reduced intake duration and wider lobe centers will increase cylinder pressures.


Overlap does not reduce compression effects, intake valve closing does. Longer intake duration and narrower lobe centers generally means lower cylinder pressures.


Exhaust recirculation can be increased with overlap, and *reduces* cylinder temperatures by reducing the amount of combustible material in the chamber at the time of ignition.

Edited by Xnke
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