I have a 177 weiand on a 355 SBC it makes 4#s of boost with the 3.48 top pulley and 14#s with the 2.66 top pulley I ran C16 in it with the 14#s of boost. I called the weiand tech line to find out how safe the motor would be with 14#s He said it was way to much boost for that motor and refered me to the web site boost chart. Is all boost the same? The chart seams to be generic for all weiand superchargers Is 10#s of boost from a small 177 the same as 10 #s from a 6 or 8-71 blower? On my SBC with 8.2 Static comp with 14#s of boost the effective compression is 16.1 way above the 12.1 they recomend on pump gas. I built the motor with all forged internals JE pistons etc to run added boost. Im trying to learn from people that have real world experiances. I have a small cam in the car its a comp NX 262 with 460/480 lift recomended by comp cams. Could I be reading artificial boost? How much boost is my limit? Thank you in advance for any and all help.

Boost is just a back pressure reading (pressure differential) of what is not getting into the motor.

You have to qualify the pressure difference by temperature as compressing air always increases the air temperture, and the density or mass (number of air molecules within that space).

Three things contribute to that extra pressure between the supercharger outlet and engine inlet ("boost") 1. Is the fact that the supercharger is moving (pumping) more air than the engine itself would move. (as adjusted by the blower pulley drive ratio)
2. Is the heating of that air caused by the pumping action and air compression.
3. The engine heat picked up by the supercharger case.

If you were to improve the enigines ability to breath at high rpm, the boost shown on the gauge would go down and the engine power output would go up.
EG: swap cams for one with more duration.
You'll still need a higher octane fuel to avoid detonation as the in cylinder pressure is higher yet the boost guage reads lower.

Ultimately it is the amount of air that goes in and out of the motor that determines how much power it makes, not the boost reading on the gauge itself.

Thank you for your reply