QuickStyle

Does anyone know the reason behind GM changing its heater return hose setup from the water pump to the radiator in the later years? was there some benefit to it?

Reason i ask is because it takes a long time for my trans temp to get in its operating range. after about 15 minutes of driving its barely over the 100* mark, and im thinking its because my current setup is routed to return the heater hose to the water pump. im thinking about welding a bung in my radiator to return it there to help warm up the trans fluid faster. It shifts all crazy until it gets in the 120* range, so i want it to warm up a lot faster.

Any thoughts on this? would it really help the warm up time of the trans by routing it to the radiator instead? and by routing it to the radiator would it essentially make the cool side of the radiator hotter to where it wouldnt cool the fluid as well once at operating temperature since hot coolant will be running straight to it rather than across the radiator first dropping it 20* or so.

My setup: 2600 stall, fluid runs thru radiator cooler (griffen aluminum 2 row 1.5" tubes) then thru a b&m super cooler 11x12x1.5

Im a bit confused on if it would benefit at all from changing the return to the radiator, so any insight on my thought is appreciated.

RED_DRAGON_85

switch your lines.
make it run thru the super cooler first, then go into the radiator.
your other option is to move the trans cooler to behind the radiator so it only gets warm air.
you could also install a blanket over half the trans cooler and see what that does.

out of curiosity's sake, where are you measuring the temperature of the trans fluid?
ideally, you want two temperatures.
t1: temperature at transmission exit
t2: temperature at transmission inlet

this way you know exactly how effective your cooling system is, and you can keep an eye on your transmission stress as well.
if t1 is high, you are slipping or generating too much heat.
if t2 is high, but t1 is ok, you are not effectively cooling, and t1 will start to climb


to answer your original question, no.
you want the radiator to remain as COOL AS POSSIBLE

skirkland1980

iTrader: (2)

i had my heater hose connected at the radiator and it made my HVAC heat not so warm.

QuickStyle

Nice response red dragon. I am messuring the temperature on the pressure port on the driver side of the case, it was similar in temperature when i was messuring it off the return line.

I have since starting this thread already swapped my trans lines, it now goes to my super cooler then thru the radiator back to the trans, the trans fluid seems to warm up faster now, takes about 3-5 minutes to see 100* trans temp.

whether the heater return was to go back to the water pump or radiator end tank, it all ends back in the water pump anyway, just makes the cool side of the radiator hotter faster, which in turn should warm my trans fluid faster, and returning it to the end tank is the stock configuration anyway, GM had to have some line of thinking to change the return to the endtank, i just dont know what.

As for wanting the radiator to remain cool as possible, i have to disagree, because the hotter the radiator is, the more heat is can remove from the system since the temperature drop is the difference between the radiator water temp and the outside temp times the efficiency. for example if the water temp is 210 minus the outside temp for example 70* the difference being 140 times the efficiency for example 50% would give a temp drop of 70* across the radiator. with a cooler radiator inlet temp for example of 195 we only see a temp drop of 62.5* therefor hotter radiator removes more heat. I think this could possibly be the reason gm returns the heater to the radiator instead of the water pump.

for my particular issue i think it will warm trans fluid even faster if i were to run it back to the radiator since it takes a good 5 minutes for the engine to reach operating temperature, then how ever long it takes for the hot water to reach the cool side of the radiator. but i dont want it to get too hot to where my trans fluid can't cool down enough when its time. i want a max of 180* trans fluid.

You can see the predicament im in here, i don't know if it should weld the bung in or not, i suppose i can weld it in and test it out, and if it doesnt work out well i can always plug it and run it back to the water pump. but i would stll like some more insight on my thoughts, any help is appreciated.

chads89ta

iTrader: (6)

i was always told the cooler the better

Blind Driver

That is the correct routing.