Why did they run coolant around the throttle body?

[1bd87]

Drain This

Hey I'll make this easy drain the tank of your air comressor do it slow you get water do it fast you get ice chunks. Try it it's fun!

 

[Turbo6Smackdown]

ok, let me just tell you this. im in detroit, with my tb lines blocked. i drove several days in the freezing cold, with ZERO problems. its just another theory that looked good on paper, but proved to be about as useful as your appendix. my car runs the same with 'em both open and closed.

 

[captndave737]

tb coolant

It's all about emissions. It's to bring everything up to temp quicker. I used to have them blocked off and along with a 160 degree thermostat and a gutted cat would barely pass emissions or barely fail. Put the lines back on and always just passed, put in 195 degree thermostat and it wasn't even close to failing so I'd make the change before going and just change it back afterwards.

Carb. icing is from the rapid pressure drop going across the venturis combined with high humidity and it can happen more easily at 50 degrees, where high humidity contains more actual water tan at 30.

Any private pilot training manual will have a section on this subject because it has killed and continues to kill people. Back when I was flying the little palnes there was one model of cessna that iced every time I flew with an OAT between 70 degrees and 40 degrees with the temp. dewpoint spread less than 15 degrees.

 

[Ormand]

Vader, your imagination is fantastic! That scenario about going to work, coming out for lunch- man, you should write for some soap opera. Not much science there, though. The coolant stops flowing when you shut the engine off, so there will no, repeat NO, effect on the rate at which the throttle body cools down. It will cool about as fast as the rest of the engine, maybe a little faster since there is not much mass of metal there compared to the block/crank/heads. Also, since you clearly haven't looked, the coolant line attaches to the intake manifold BEFORE the thermostat. Thermostat doesn't stop flow to the heater, or to the throttle body. In moderately cold weather, the engine won't get down anywhere near ambient in a few hours- just too much heat stored in all that metal. So, the engine will start easier than it did after sitting overnight. The shop manual is correct, the coolant helps with quicker warm up, which, in turn, improves emissions, as captndave pointed out.

 

[VadersV6]

Given that there is a gasket sandwiched between the TB and the plenum lid, it cant conduct much heat. You run a coolant line to it, now you can bathe the TB in warm coolant that every other component is exposed to. Now you can make sure the aluminum contracts at the right rate (as everything else) and doesnt start binding the blades and making the screws come loose...and if youve got the tb cooling at a different rate than the manifold, something is going to start to dew. With coolant flowing through it, the heat in the TB has somewhere to go.

 

[Sleeper]

Oh what the heck, I'll throw a curve into this
Anybody ever consider the effect it has on cooling the TB? Keeping a consistant temp? Just thinking about heat soak from the engine itself. May be miniscule during a WOT run, but idling around town in traffic, with little blips... Would be interesting to to back to back tests using a heat gun.

Paul

 

[Turbo6Smackdown]

ok ok guys.. i think weve established, that if most of us run a modded TR, weve pretty much thrown emissions out the window. noone that runs a performance car gives two ****s about emissions lol. At any rate, if you do, you probably have your quick little fixes you perform right before you smog your car, if you live in a state that requires it. regardless, its a mod everyone does, and it really makes no difference anyways. all the mods are done, and i dont see anyone in the forseeable future returning their stuff to stock, unless theyre concourse cars. the mods are done, and are water under the bridge now... were beating up a non issue. none of our TB's are heated and our cars run fine. its the way we live now. next subject.

 

[tb3]

I was curious about why the engineers did this in the first place. There was a reason they had for doing it, or otherwise I doubt they would've bothered. Before I posted the question the only thing I could really come up with on my own was for some kind of emissions thing. I am familiar with carb ice being I am a aircraft mech, and I know there are certain cars that had problems with this years ago. A friend of mine had a tr6 that had a straight 6 in it with a really long intake manifold that sat way off to the side. When temp and humidity was at the right conditions, it would get carb ice. I really didn't give ice any thought on these cars being the turbo is a pretty good source of intake heat. I have a 04 Lesabre with the 3800 engine for a daily driver. Guess I'll go take a look at it and see if theres any plumbing around the throttle body. I have capped my lines and haven't had any problems so far. I just thought it would be nice to know what the reasoning, or theory was. Knowledge is power