PDA

View Full Version : Question about boost/flow, fuel, and timing



91supacoop
05-22-2009, 05:23 PM
This is a general question...nothing specific to my car or anything.

If you are targeting MBT, has anyone encountered a situation where TOO much air is getting into the engine?

The reason I ask is because someone who was a calibrator for ford mentioned that they had changed the cam timing to allow more air into the engine, eventually so much air got into the engine that detonation was occurring, and they needed to pull timing. Ultimately they ended up producing less torque, even with more air flowing into the engine.

XR7 Dave
05-22-2009, 05:49 PM
This is a general question...nothing specific to my car or anything.

If you are targeting MBT, has anyone encountered a situation where TOO much air is getting into the engine?

The reason I ask is because someone who was a calibrator for ford mentioned that they had changed the cam timing to allow more air into the engine, eventually so much air got into the engine that detonation was occurring, and they needed to pull timing. Ultimately they ended up producing less torque, even with more air flowing into the engine.

Its not a matter of too much air, but if your cylinder pressure and heat exceed the limits for the available fuel requiring you to pull timing back, past a certain point you will make less power than if you lowered cylinder pressure (or heat) so that you can run closer to ideal timing.