TB Coolant Crossover/Bypass, Any Disadvantages?
 

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.

Re: TB coolant crossover,any disadvantages?
 

I have the by-pass and no problems. I don't have to worry about any leaks at the TB.

Re: TB coolant crossover,any disadvantages?
 

One disadvantage is if you don't flare the ends of the bypass pipe, and the rubber line slips off and streams coolant under your plenum killing your starter. Ask me how I know about that one?

Re: TB coolant crossover,any disadvantages?
 

I have, no issues on my DD in AZ heat either

Re: TB coolant crossover,any disadvantages?
 

I bypassed both the throttle body and the entire plenum, no regrets. I did a write up on it for HOTB - last year I think?

Re: TB coolant crossover,any disadvantages?
 

Yep! I didn't have the bypass though. The stock hose ruptured, facing towards the plenum (of course) & flooded the valley. Stuck in a gas station, fixed it, starter toast but easily push started (small miracle).

Lesson: don't forget the "little" coolant hoses when you replace the "big" ones.

Re: TB coolant crossover,any disadvantages?
 

Thanks for the replies.The reason I want to do this is to save the paint on the TB.

Re: TB coolant crossover,any disadvantages?
 

Anybody got some pictures of this mod?I broke out the tube cutter,bender,flaring tool and then ran into a wall.The plan was to make a hard line and run it under the front of the plenum keeping the coolant line intact,no room wont work.Next plan was to plug the line on both sides of the TB with the lines intact keeping the look stock.My question is the small line coming off the TB going back into the plenum,is this for a return back into the system only?Ive even thought about removing the TB plate and filling the cavity with epoxy to seal out the coolant,thats a bit drastic.

Re: TB coolant crossover,any disadvantages?
 

http://zr1specialist.com/HAT%20Web/p...t%20bypass.htm

Is this what you're looking for?

Re: TB coolant crossover,any disadvantages?
 

Thats it,I was all set to make one of these but couldnt see any room under the plenum.Now I know it can work Ill go take another look,Thanks for the link.