Just put in K24's with GT2 intercoolers. What kind of cool down do you guys suggest after spirited driving??

 

It has been tested by the gurus and 1min is the minimum, 2 is optimal and after that is heat soak.

 

Exactly!!

 

Pardon my ignorance, but can someone please define "heat soak" for me.

 

Well your car is hot after a drive, that's why you would need a cool down to let the oil cool in the turbo's, that's what its mainly for! Now, you would get heatsoak if you let it idle while hot for more then a 2-3min cool down period because your car isnt getting any air in it or moving for further cooling processes, im sure someone can explain this alot better, but here's just a brief explanation!

 

So if you let it idle for more that 3 or 4 minutes that's bad?

 

2-3 min bro

 

If you let it idle after running it hard for more then 3 minutes,s ome say it starts getting hot again because there is no airflow, which means it will start getting heatsoak again! But in general if you drive it normal or let it startup and idle there isnt a problem.

 

Heatsoak is directly related to thermo dynamics and particularly thermal inertia the best way I find to describe is for instance when you turn off an engine if you turn the ignition on 5 minutes later you'll see (on the dash) the temperature reading is actually higher than before you turned it off thermal inertia makes the metal parts rise their temp. because the cooling system stopped. Did you know the F1 one engines before the 2 races per engine after a hard run couldn't be turned off WITHOUT additional cooling? If they did they'd seize as all the expansion rates are calculated for a specific operating temperature and heatsoaking would make the pistons expand beyond clearance.

 

1 minute it is.............. is it beneficial to open the rear lid after that point or does that negate the effect of the fan if it kicks in?

 

I'm for NOT opening the hood. I heard an explanation which convvinced me and I never did it again.

As you know the fan can operate long after the car is turned off and its triggered by a temp sensor on the upper section of the engine compartment which closes the circuit at 75ºC. The fan will push the air from top to bottom which is from the colder to the hotter part (headers, turbo's, exhaust, etc) of the the engine compartment. If you open the lid convection will naturally make the heated air surrounding the headers, turbo's, etc.) rising and literally cook the hoses, sensors, plastic parts, etc.

I first heard this from "1999PORSCHE" (which I haven't heard from in a long time) and after that my research seemed to comfirm this.

 

I dont know how often or the chances that could happen, but it sounds right. Plain and simple though, with the decklid open it defeats the extra cooling purposes from the fan

 

Do you still need the 1-2 minute cool down after a casual highway drive where you're not in the boost? Do the turbos still spin at cruising speeds with the boost simply bled off or do the turbos not work hard and get hot during a casual drive?

 

60-120 seconds regardless of how you drove (according to the tuners...one in particular that makes turbos )...this includes stops for gas! I hope it is OK to post this quote

 

Always curious about this cool down period....

Why casual driving (low strain and < 2500rpm certainly without turbos engaged) one would do in a residential area just before driving into the garage would not count in the cool down period?

Wouldn't this help the turbos cooling down (oil flowing, air flowing, turbos not generating heat)?

Can someone explain in more detail...

Fortunately, those with cabs get to feel like they are actively doing something (i.e., watching the top close) instead of just fiddling while waiting for the cool down.