Bypassing throttle body coolant lines?

[Ohiocruiser]

So, i've just read the article saying that the only reason throttle body would have a coolant going through it, was to prevet it from freezing in winter months. Not sure, what can freeze in there. And all the cars that came without those lines would ask the same question, i am sure. But even if that is correct, bypassing them during warm months should keep ait down. Any thoughts?

 

[DonD]

Would sound like a good question. I don't personally know what Kia engineers would say. Don

 

[Ohiocruiser]

Would sound like a good question. I don't personally know what Kia engineers would say. Don

I know what a kia engineers would say about installing piggyback tune. Doesn't stop people from installing it

 

[DonD]

I know what a kia engineers would say about installing piggyback tune. Doesn't stop people from installing it

Two different issues I'd think. Don

 

[Ohiocruiser]

Two different issues I'd think. Don

Nope. Both possibly increasing performance

 

[DonD]

Nope. Both possibly increasing performance

Tunes, though possibly voiding the warranty, do increase performance. Would think a cooler throttle body would incease power as well. Don

 

[Ohiocruiser]

Tunes, though possibly voiding the warranty, do increase performance. Would think a cooler throttle body would incease power as well. Don

Hopefully, someone who understand that things can comment on it.

 

[DonD]

There are details for sure but if your engine grenades and you have a tune on it, can't believe Kia will give you a new engine. Why should they, you've modified their engine parameters. Don

 

[M'Kehyah]

Coolant is to warm the TB so it does not ice up in cold/humid conditions. Especially in northern climates. Not needed any other time.

I did this in my Xterra and had no icing/negative impact noted (I live in Dayton, OH).
Does it make a noticeable difference? I doubt it - but it DOES have a benefit and the cost is so small - I will probably do this mod too.

I assume you would simply buy a barbed hose connector and connect the two ends to bypass the TB.

 

[oddball]

The throttle body and blade form a venturi, especially when it's nearly closed. That causes a large pressure drop. Cold, humid air will quickly freeze in those conditions. So it's possible for the blade to actually freeze in place near idle.
Every car has had some kind of anti-freezing system since at least the early 60's. Before MPFI they would run exhaust gasses under the intake manifold to make the entire intake plus carb/TBI toasty warm. Back then, cutting off that "feature" made a huge change because we're talking about cooling the *entire* intake by 100 degrees or more.

Now they just make a little warming loop right around the narrowest part of the bore so ice won't form.

There is zero performance impact. It's not enough space to make any impact on IAT. You can bypass if it makes you feel better, but the only effect is the throttle body might freeze up if you're in a cold climate. And you'll get some air in the coolant system which might be a real PITA to get out. I haven't had to burp this system yet, so I don't know. Some cars are super simple, some cars (like my '02 Lincoln) require a 1 to 2 hour procedure to get air out of the coolant system. Air in the coolant passages can get stuck, resulting in a spot that's not getting cooled at all (air is actually an excellent insulator).

For minimum IAT you're better off insulating all the intake pipes to isolate them from engine bay heat and ensuring all intake air is coming from in front of the core support.

 

[Ohiocruiser]

The throttle body and blade form a venturi, especially when it's nearly closed. That causes a large pressure drop. Cold, humid air will quickly freeze in those conditions. So it's possible for the blade to actually freeze in place near idle.
Every car has had some kind of anti-freezing system since at least the early 60's. Before MPFI they would run exhaust gasses under the intake manifold to make the entire intake plus carb/TBI toasty warm. Back then, cutting off that "feature" made a huge change because we're talking about cooling the *entire* intake by 100 degrees or more.

Now they just make a little warming loop right around the narrowest part of the bore so ice won't form.

There is zero performance impact. It's not enough space to make any impact on IAT. You can bypass if it makes you feel better, but the only effect is the throttle body might freeze up if you're in a cold climate. And you'll get some air in the coolant system which might be a real PITA to get out. I haven't had to burp this system yet, so I don't know. Some cars are super simple, some cars (like my '02 Lincoln) require a 1 to 2 hour procedure to get air out of the coolant system. Air in the coolant passages can get stuck, resulting in a spot that's not getting cooled at all (air is actually an excellent insulator).

For minimum IAT you're better off insulating all the intake pipes to isolate them from engine bay heat and ensuring all intake air is coming from in front of the core support.

These are a good points. Maybe i'll get a scanner to measure iat with and without those lines, just to see the difference. And i seriously never knew about the need for some heat source for TB. good to know.

 

[oddball]

That feature is much more important on Carb/TBI systems because fuel is evaporating at that same point. Lower the temp, throw in some humidity, and it's really easy for ice to form.
Now that we're just talking air (and not air+fuel) it's much harder for it to happen, but they design cars to run anywhere at any time.

IATs vary a huge amount, so to do a comparison you have to keep track of how fast you're moving, how long you're stopped, ambient temp, how long the engine's been running, etc. e.g., I have the JT intercooler and pipes, plus bigmouth snorkels. IATs at a stop will go up 40 degrees or more. Typical cruising temp is 10 to 20 degrees over ambient depending on conditions under the hood.

 

[DrMario86]

I remember back in my CB7 Accord days that was a popular mod. Bisimoto made insulated intake manifold and TB gaskets to keep the engine heat away from the air for as long as possible. Seemed to me like mostly feel-good mod rather than making huge differences in IATs. They claim 7hp on the F22 (140ish hp) engine with manifold temps reduced by 50 deg but I'm skeptical of all things. LINK in case somebody wants to weigh in.