You don't need the Motordyne Copper Bypass unless you live somewhere where the temperature reaches below freezing often. Living in TX makes the Motordyne Copper Bypass obsolete, but if you have it installed I don't think it affects the spacer at all in warm temperatures.
It actually works the other way around . . let me see if I can clarify: The MD Copper Bypass shuts off the continual hot-water flow to the area on the intake plenum around where the throttle body mounts to it. The factory does this to prevent icing-up that occurs in that area in extreme cold temp's, and improves drivability in such areas like up north where it snows a lot. But obviously, here in triple-digit-heat country, that's hardly a problem to say the least . .
The MD Copper Bypass is a copper plate-like gasket that has a small section of metal tube attached to it, along with a separate inline shutoff valve. You mount this between the throttle body and the intake plenum, like where the regular gasket goes. It does two things: 1) If you leave the water flow on, it's still better than the OEM setup because it's only heating the small area right next to the TB butterfly valve where the icing occurs - vs. heating the whole front area of the plenum which robs power, and 2) The inline shutoff valve can be closed for
no heating at all for max performance, except in extreme-cold conditions (below freezing).
This is the way mine is set, and has been set for years now - even in freezing or slightly below freezing temp's I found that it still started and ran fine, and the loss in drivability was minimal at best and only even slightly noticeable for the first mile the car was driven . . past then it warmed up enough on it's own that there was no need to have it on. I'm sure if I ever go up to RI to see my sister and there's several feet of snow on the ground, then THAT would be a good time to (finally) open the inline valve for heating (only) the TB butterfly-valve (NOT the whole plenum, which is unnecessary).
Bottom line: MD Copper Bypass with inline hot water valve OPEN: Allows just enough heating to do the job, JUST in the area it's needed and not all around it too (like OEM). Valve CLOSED: This shuts off ALL heating to that area completely.
With so many other cool things like micro-polished crankshafts, carbon-fiber driveshafts (Z only), etc. I would have thought the factory would make it's own (automatic) hot-water shutoff device for this for cars not up north and instead down south in triple-digit heat, but apparently the factory skimped in this dept. much like they did with the starving of the two front cylinders for airflow that occurred from the sloping of the hood. Guess the "bean counters" won in those dept's. . .
