TB Coolant Crossover/Bypass, Any Disadvantages?

[Z51JEFF]

How many have done this?

Throttle Body Heat Bypass Line by Marc Haibeck

Possible reasons to bypass the throttle body?

1) Much "stuff" is under the plenum (starter, A/C compressor, coils, etc). If bypassed, you don't have to fuss with draining coolant and refilling it (and getting the air out of the system). Bypassing, or even plugging the passages off entirely, eliminates both PIA parts associated with coolant draining. With an air ratchet, one can have the plenum off in about 5 minutes (if you leave the throttle lines connected), and on again in a few more (depending on condition of the gaskets). Fussing with coolant can easily add an hour to that process, has been my experience.

2) The plenum runs cooler which better for performance. Marc Haibeck has run his ZR-1 in the Chicago area for years and in sub freezing temperatures w/o any problem with icing.

3) Corrosion can be an issue with coolant running through the plenum.