TWIFOSP

This is a hard one to search for, can't get the right keyword to pull up anything usefull.

What is a good basis for turbo cooling?

I have an HKS turbo timer. Its supposed to detect how long you've been driving, and how hard you boost and then time the cool down accordingly. But unless I have it set wrong, it seems to only do 30 seconds each time. Granted I'm still breaking in a new engine so I haven't really even boosted the second turbo yet.

I want to program the memory settings so I don't have to trust the automatic setting so my question is, how long should you let it cool if you are just doing some high way driving? Normal start and stop driving, and then cruising to about 60-80 for a while...

If there is already a thread on this and you know it, please link it, call me a stupid n00b and I'll be on my merry way

neevosh

Not very long under normal driving. The stock turbos are water cooled and don't really need to be cooled down.

BrianK

hmm... I posted a thread on this a while back, but can't seem to find it, soo... what neevosh said is correct. I read an article that intereviewed an engineer from Garrett who said that turbo timers on watered cooled turbos are close to worthless. He said that idling the car for a few seconds after you stop is plenty - as long as the turbine has enough time to stop spinning before you shut it down, you're fine. He also said that idling the car for a long time does more harm than good - being that it will allow the rest of the engine to heat up which isn't good on anything.

suprfast

well i have an apexi turbo timer and it times for 20 seconds. i just do that for the hell of it. you can however set it to run for 10 minutes after the car is turned off. just turn the car off, and go back to the on position. your car will count down again. i think i did waste my money on this part, but i already have it, so...
kris

DavidDeco

Uhh...I don't think so. By keeping the car on you keep coolant flowing. AT least on my car, I can attest to the fact that upon shut off my car jumps a good 10 deg Celsius depending on length of the turbo timer.

I just increased the length of my time doubling what I had before and noticed some reduction in this off ignition temperature increase but it still goes up 5-7 degrees.

I won't debate the turbos because I don't know. However I dispute the fact that leaving the car idling after driving is harmful. AT least not on my car...not even close. I think it helps a significant bit. I just hate the damn music....(yes you turn it off but it always resets when you disconnect the battery).

RedX7

I'd say idling anywhere from 30 seconds to a minute is enough. Any less and you won't get a thorough cool down of the turbos, any more the engine will start to warm up. Just my $0.02.

DavidDeco

Just keep in mind the moment your engine truly shuts off coolant stops flowing....turbos aside, the engine needs more than 1 minute IMHO and what I've seen factually on my own car.

I never noticed before with the stcok water temp gauge (who would?). With the PowerFC I'm very attuned to it. Your temps skyrocket once coolant is cut if still hot. On my car that means at least 5 minutes on normal driving but then I run a little hot with A/C (cured my non A/C issue...now run 89 but still notice the same once engine is cut - that is skyrockets to above 100).

RedX7

[QUOTE]Originally posted by DavidDeco
[B]

Just keep in mind the moment your engine truly shuts off coolant stops flowing....turbos aside, the engine needs more than 1 minute IMHO and what I've seen factually on my own car.

True, very true. But once you stop moving the coolant is no longer getting fresh air to circulate in. And depending on the temp outside, it might make it worse.

DavidDeco

[QUOTE]Originally posted by RedX7
[B]Sounds reasonable but I think I'm in a great test climate. Florida. Late Summer. 90+ deg F weather.

I've been very attuned to this these last months. I just blew a water seal a few months ago and my car has been under reconstruction since then. I have spent a fortune which I will publish shortly when timeslips, dyno run, pics, and final price tag come in.

I religiously check temperatures, shut my engine off and return.

My empirical point being that theory aside, with no circulation, any coolant flowing is better than no coolant flowing and increasing my turbo timer from an average of 4-5 minutes to 9 minutes has resulted in my PowerFC water temp readings being about 5-7 deg higher than at turn off instead of 10-14.

Just my observations. And they have been religious these past weeks. Again = at least for my car.

RedX7

I totally agree with you. It ultimately comes down to where you live, and what condition your car is in.

TWIFOSP

cool, well I have a water temp guage on the way... I'll check it after various cool downs and see whats best for m'lady.

BrianK

you let your car idle for 9 minutes to save 7 degrees *after* you shut off the car?!

not to flame or anything, but that, in my book, falls under the category of "more harm than good" - I'm assuming you have some sort of fan mod going as well, or at the very least turn your interior fans on to 3 to load up the electrical system so the radiator fans turn on sooner... if not, then it's *deffinitely* more harm than good.

I'll stick with my "coast into the driveway from as far away as possible then timer for 30 seconds after key off" method.

DavidDeco

Yes my fans on. I should have been explict about that I guess.

The end point is that my car does not experience as big of spike in water temp with the turbo timer as it does simply turning it off. Moreso, by lengthening the time it has helped it. That certainly is not more harm than good, no??