This is the part of the system I found caught my eye.On my 383 build I just posted how the cam manufacture doesn't suggest a ,as example 108 lobe center.Well that does effect in the RPM range the torque band occurs.So it had me thinking that what Pat and I had discussed about off idle was going to be a trade off.Yepper-I think we all know there are some with almost every build on a engine.But the L/C change would surely effect almost everything we had worked up.So here is a quote from the link.Look at the last part of it.It does seem to make sense.Oh yeah-I forgot to say I have a friend in Calli who is using a old Edelbrock system towing a sand trailer getting soft peddling in the low 20's for gas mileage with his 355 in a Astro.

How Does it Work?

Any naturally aspirated engine, regardless of brand, size, combination of parts, etc., requires a given air/fuel ratio, at a given load. These ratios do not change from engine to engine, until you get into forced induction applications. (We'll get to that later). The needed air/fuel ratio changes with such things as engine temperature, air temperature, and atmospheric pressure, but the needed changes, again, are the same for all engines. The task for any management system is to add the correct amount of fuel to the amount of air that the engine uses. Carburetors do it mechanically, and so, are mechanically limited as to how accurate they can be. Speed density systems do it by comparing the readings from various sensors to tables within the engine controller to try to determine the amount of air the engine is using. This actually works very well, IF THE VALUES IN THE TABLES ARE CORRECT, and there lies the challenge. There are a lot of values, and a lot of tables, and a professional tuner is required to enter the correct values into all of those cells in all of those tables. But you are not done there! The next step is to drive the vehicle in the real world, and adjust all of those values to tune out all of the drivability issues you will have. The other problem is speed density's limited ability to self adjust, and so, your laptop must permanently reside in the passenger's seat. Worse than that, non-programmable, or pre-programmed speed density systems arrive at your door with the programming done. They have been pre-tuned at the manufacturer on the dyno with a pre-determined combination of parts on a specific engine. That would be great, but remember the part where this does not really work very well in the real world? Well, with these systems, you can't even fix it! Even worse, if you want to make a change to your engine, you simply can't.

Mass-Flo does it differently. There is a Mass Air Flow Meter Hidden away inside your air cleaner. This meter can actually measure the amount of air that is entering your engine, and again, if you know how much air the engine is using, then you just add the correct amount of fuel. It's that simple. The air/fuel ratio is adjusted accordingly to compensate for the load, and variances in engine temperature, air temperature, and atmospheric pressure by reading values from sensors that are included in the system. If you decide to make improvements to your engine, Mass-Flo simply adapts to those changes. Keep in mind... An engine is just a big air pump. Changing heads, camshafts, intakes, exhaust systems, displacement, etc., are just ways of making your air pump more efficient, or in other words, using more air. Since Mass-Flo measures the amount of air the engine is using, it simply adds the correct amount of fuel. With speed density, it's back to the dyno to start all over again.

In forced induction applications, the ratios are different, and a different tune is needed. We also have a tune to cover those applications. In fact, Mass-Flo can be adapted just about anywhere. If you want something made custom, let us know. We can do dual quads, and other applications where two Mass Air Meters are required. In all cases, no tuning is ever required by the customer.

There's one other thing we should mention... Speed density relies heavily on the signal from the MAP (manifold air pressure) sensor to determine how much fuel to add. This sensor measures the engine's vacuum at the manifold. So what happens when your camshaft produces poor vacuum? You guessed it... Horrible drivability is the result." Mass-Flo does not use a MAP sensor. You can use any camshaft you want with our system."