quick question about water system

[Jase86]

I would think if we go to all the trouble of trying to keep intake air cold - warming up the throttle body with hot coolant is counter productive?

A lot of things that the OEM does for emissions reduction and daily driveability is counter productive to outright performance.

[dave2221]

interesting.......

[ke70dave]

just thought i would chime in here....

i have blocked off everything and i have quote: "a perfectly driveable car when cold". my cold start injector is all hooked up and opperable. the only thing is i usually leave it idle for like 20-30 secs before i start driving. as i dont have the idle up working (not even sure how it works on a 4age, i just know i dont have it) it just idles at like 1000rpm regardless of temperature.

keep in mind that the coolant flowing through your TB is not going to help your cold start, since when you are starting the car when its cold...the water is still cold....so its not heating up your TB..... ie no advantage. apparently when it gets REALLY cold (like minus temperatures, snowing ice etc) the air can get so cold that it doesnt atomise the fuel properly which is why they heat the throttle body with the warm coolant (engine now at opperating temp, so coolant is hot). i hear this is an even bigger problem on cars with front mount intercoolers as the air get sooo cold under normal driving conditions (ie not hard boost) that its just too cold. there is a technical term for this but i cant remember what it is....but its only a problem if your gonna drive your car in the snow etc.

good thing im not driving my car on skii trip this year!!

[yoshimitsu9]

my argument to that would be the air would be moving quick enough through the throttle body that it wouldnt heat up.

even if it did "warm" the air up, its moving fast enough that it would only cause a poofteenth of a kw loss in power

[Golberg]

Sigh, the function has nothing to do with warming the throttle body up, in fact you'd find that it probably makes little to no difference to the throttle body temp at all.

The water temperature adjusts a valve which allows more AIR to flow into the manifold, which in turn increases idle speed. When the water is cold, the valve is wide open allowing the extra air in, when it is shut the idle comes down to 800rpm.