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Guest Message by DevFuse

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bypass the coolant line at the TB?

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6 replies to this topic

#1 subeman90



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Posted 16 September 2004 - 07:57 PM

as the subject says....why? jonofscio has this in his profile.... why???? what does this do???? am I missing something good????


#2 JonOfScio



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  • Corvallis, OR

Posted 17 September 2004 - 08:04 AM

notice a power difference when you drive your car hard when its 60 degrees outside and then when it's 100 degrees outside? Air expands at higher temperatures, and so when the coolant is heating your throttle body, it's heating the air intake temp of the charge coming in. lower the temp, the more condensed air is... colder air is always better, so long as it doesn't contain too much moisture... (why do you think intercoolers exist? lol)

The idea why it's there is not for emissions, but for cold weather people. Because it's supposed to "keep your throttle body from icing over" but the funny point is that if you live in a cold climate, the mere fact that you aren't driving your car, and it's stopped, and there's cold coolant in there is not going to stop your throttle body from icing over if it was going to without the coolant lines hooked up. Coolant in the TB is arbitrary to whether or not this would heppen... In my opinion, from talking to people who live in colder climates who have done this, (and yes, this is a fairly common thing to do with cars in general) is that it's only a restrictive device placed on engine performance. I can't understand why there should be any heating in that area anyhow.

And afterall, wouldn't having the maf sensor read the same temperature air that's going into the manifold be more accurate for fuel equations than if it were say 15 degrees hotter? And wouldn't you want your ECUs air intake temp sensor to match more closely the air coming in? (from what I understand, on the cars so equipped, it's before the TB)

btw - one person who had a turbo motor measured the difference. said the air intake charge changed about 15 degrees cooler. I'm not sure if it's the same or any different for us n/a guys, but, I know now I can touch my TB when it's completely warmed up and not have to worry about frying my hand! it used to be so hot I couldn't touch it for longer than a second.

#3 Legacy777



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Posted 17 September 2004 - 08:31 AM

You're not really going to gain any hp from this....however throttle response will be better.

If you live in colder climates, there is a possibility of the TB icing over if given the right temp and humidity.....it'd be pretty rare, however possible.

#4 DerFahrer


    Formerly subyluvr2212

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Posted 17 September 2004 - 07:44 PM

You're not really going to gain any hp from this....however throttle response will be better.

Agreed. I also noticed that it cut down on the pinging I used to have, which would make sense if the intake charge is slightly cooler...

#5 Setright


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Posted 18 September 2004 - 01:22 AM

It must really be a minimal advantage. I have a 3inch pipe taking air from inside the fender cavity - through a velocity stack of course! - and delivering it straight into the filter box on top of the engine. The momentum of the air alone, will push it through the TB without affecting the volume or mass as it gets heated. I don't think there is enough heat to actually slow the air down, if you see what I mean?

Although, I would understand if this improved low engine speed throttle response, since there might be enough heat to affect the mass air flow in this condition. The easy solution of course is to keep the revs up!!

#6 subeman90



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Posted 18 September 2004 - 08:52 AM

hey subylover: those cars of yours are really nice....I just looked at the pics... I guess stuff stays nicer in Fla. (as long as the huricanes don't take them away...)


#7 Tiny Clark

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Posted 20 September 2004 - 05:31 AM

I'm not exactly sure about the throttle body, but the old carb intakes were heated to allow the car to run better when the engine was cool/cold, because the cylinder head temp was not hot enough to help vaporize the fuel.

For best results across the board, there should be a thermostat that closes the line once the engine is warm.

I'm sure it probably helps reduce cool engine smog outputs as well.

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