MAFS vs Speed Density TPI

[Daniel Burk]

Mike, The arguement against the cold start injector is that it is
an additional part that can be eliminated through compensation from the
eight main injectors.  Additionally, the cold start injector injects fuel 
into a manifold that was designed to run as a "dry" manifold. (e.g. no 
fuel, only air.)  A dry manifold design that stays dry is superior 
because the fuel will not stick to the sides of the manifold, then tear 
off in great gobs of unburned fuel.

A Speed density system also is a simplification.  A MAF sensor is much 
more complex than a pressure transducer, and is more prone to failure.  
Instead of actually measuring the air density, you measure air 
temperature and absolute pressure, then calculate the density using your 
computer.  It requires (I surmise!!!) more processing power.  The system 
is programmed to fuel maps instead of a Mass/Air calculation. (I think - 
You better ask the experts I have no practical knowledge here.)

Additionally, a MAFS sensor places a restriction into the air flow path, 
resulting in reduced performance potential.

Yet, a MAFS sensor based system is supposedly more forgiving of 
performance modifications, and allows the use of a hotter cam.  The speed 
density system requires a good vacuum signal to calculate air flow, and 
hot cams don't lend themselves well to big, stable vacuum signals.

	-- My opinion,
			-- Dan.