Throttle Body Coolant Bypass Modification DIY

[Anomoly]

i did it a few years ago on one of my hatchbacks with a ZC swap......yeah i was broke but the zc was all motor built to the max........ anyways i live in colorado where it gets real cold real fast i never had a problem with the butterfly sticking, even when it was so cold out that my 90 weight transmission oil had the consistency of honey and i would have to warm my car up for 20 minutes just so the tranny would go into gear IMO the mod did nothing for me but make me feel like somehow i cheated an engineer like a hacker on a computer, i felt no diffrence, and i had a radio shack thermometer in the intake pipe, temp was no lower.......

[The_Producer]

how exactly would a themometer in the intake pipe tell if your TB or intake manifold is running cooler? Just curious?? Or am I misunderstanding this concept of the bypass?

[_suleman]

yeah i dont get that cause the throttle body bypass is meant to cool the tb down and in the process cool some of the air down.

even with that said i say you shouldve used a ir thermometer instead of a cheap radio shack one.

Originally Posted by The_Producer

how exactly would a themometer in the intake pipe tell if your TB or intake manifold is running cooler? Just curious?? Or am I misunderstanding this concept of the bypass?

[sikb]

I am not an expert and may be wrong on everything I say. But I think you guys are wrong one your theories behind this mod. The coolant hose you are unpluging is for the fast idler thermo valve. What that thing allows more air to bypass the TB when the engine is cold. It is the reason your idle sound high right after you start a cold engine. At a certain point the coolant heats the valve up and it closes. If you guys are claiming a couple hp from this mod I would venture a guess that it is from the slight increase in airflow through the TB and not the decrease in intake temp. Additionally if some or all of you are modding it in a way that removes the bypass it would explain rough idles.

Any thoughts?

[quikflip27]

Originally Posted by sikb

I am not an expert and may be wrong on everything I say. But I think you guys are wrong one your theories behind this mod. The coolant hose you are unpluging is for the fast idler thermo valve. What that thing allows more air to bypass the TB when the engine is cold. It is the reason your idle sound high right after you start a cold engine. At a certain point the coolant heats the valve up and it closes. If you guys are claiming a couple hp from this mod I would venture a guess that it is from the slight increase in airflow through the TB and not the decrease in intake temp. Additionally if some or all of you are modding it in a way that removes the bypass it would explain rough idles.

Any thoughts?

i did this mod about a year ago to my gsr swap. the idle raised a tad but that was easily fixed via the idle screw. soon the idle began to fluctate from a dirty FITV, so i cleaned that and the problem was fixed. im convinced that the little amount of power gained is more likely from the temperature. sure there is a tad more flow since the FITV is open greater, but i cut out that variable since i brought the idle back down to the original rpm. ive heard that every 11 degrees lower in IAT, you gain 1% more power, and using that as a rule of thumb, there are gains to be expected. same base as to why people are starting to use insulating manifold gaskets. there is no possible way for the gasket to flow more air into the engine if installed properly, yet there are still power gains due to the thermal properties of the intake charge.

to the producer, it will pass emissions, even here in cali, i have a jdm gsr engine, that was the only "mod", i looked over the inspection sheet and that is not checked. the throttle bod is, but they could care less about the coolant lines
-quikflip