How to maintain 100psi with 20psi manifold pressure?

[JohnA]

Originally Posted by b_boy

...To use manifold pressure in the same way you would have to pressurize you water tank. It would have to be able to maintain 20 psi without leaking or exploding. Most poly propylene (think cloudy milk jug plastic) could withstand this pressure with a rubber gasket seal on the lid.

This could be a cheap'n'easy way to compensate for extra boost.
Good thinking!