aircooled vs. oil cooled vs. water cooled turbos?

[Machupo]

just curious what the benefits / detractions of each are...

i haven't a clue what kind my T3 on my 85 740t is... it looks like it's got a hose from the coolant bottle, so i imagine it's watercooled?

the only reason i ask is that i'm looking at a .48/.60 T3/T04E and i want it to plug right in (yes, i know i'll need new air hoses on the compressor side )

thanks in advance!

 

[Machupo]

WTF?!?!

did all of the useful people get lost in the move?

 

[Anonymous]

Aircooled = nonexistant
oilcooled = ok but won't last as long because the oil is more likely to clog in it and it will seize up earlier
watercooled = longer life same qualities as oil cooled (as far as I know.
Sean

 

[Anonymous]

Aircooled = nonexistant
oilcooled = ok but won't last as long because the oil is more likely to clog in it and it will seize up earlier
watercooled = longer life same qualities as oil cooled (as far as I know.
Sean

 

[Machupo]

hrmmm

was doing a bit more research into it, seems like aircooled turbos are the cheap, but quick preferred method for folks who are doing duallies on mousetangs and stuff like that... and porsche seems to love aircooled turbos...

oil cooled turbos seem to last longer if you keep the oil clean / clean oil filter... and you can put more boost into an oil cooled turbo than a watercooled turbo due to the higher specific heat of the oil (if you're using oil that doesn't coke easily)... but that's kind of irrelevant if i'm just going to put a larger turbo on there

the watercooled one seems to be exactly what i need. i was looking around the turbo today and it's already got a link to the coolant bottle (dunno how i missed that last time), so i'll probably go that route...

thanks

 

[CNGBrick]

There is no such thing as an "air cooled" turbo. All turbos have oil circulating through them providing lubrication for the bearings and drawing some heat away. Water cooled turbos have an additional water jacket around them providing additional cooling. Water and oil do not have an effect on performance (oil may have a minor effect) other than keeping the turbo alive. A "water cooled" turbo is in effect a water and oil cooled turbo and is the preferred option for longevity. Oil cooled turbos are simpler to install.

Regarding the issue of heat: cold air is better than hot air as far as engine performance is concerned. The heating of air in a turbo comes mainly from the rapid compression of air in the compressor side, not from oil, water or exhaust heat.

Hope this helps.

Richard Thomas

 

[Machupo]

Regarding the issue of heat: cold air is better than hot air as far as engine performance is concerned. The heating of air in a turbo comes mainly from the rapid compression of air in the compressor side, not from oil, water or exhaust heat.

hence the water inj. system that i'm building

 

[DaButcher]

Ok, Ill bump this thread up from the grave!

Should I fit water cooling on my turbos?
They accept both oil (offcourse, lol) and water.

I was told that watercooling them is "overkill", that its just to protect the turbos from the "noobs" which kill the engine without letting it run at idle before turning it off.

Any inputs?
Also, Can I cut this pipe

You see the waterpipe there, can I cut it and put a hose instead of the part which is colliding with the turbo? eg. if I find a silicone hose with the same diametre?

 

[740ATL]

dude. Bumped threads from the dead almost never work. Just start a new thread.

 

[Forg]

I was told that watercooling them is "overkill", that its just to protect the turbos from the "noobs" which kill the engine without letting it run at idle before turning it off.

Nope, go the water cooling. You still kill water-cooled turbos by turning the engine off while the turbo's still hot; so that argument is a piece of rubbish. It's more about simply keeping the heat inside the turbo down a bit; it has to make your oil last longer as it's not getting so hot, and it has to make your turbo last longer for the same reason.

You can "get away with" not hooking up the water, if it's all too much trouble and you don't care about the reduced turbo life (how much? I don't know). However it's far from optimal. It's not as far from optimal as not running an intercooler; it's probably similar to running a junkyard fuel-pump in a turbo car that's had the boost wound up to 20psi.

Can't answer your pipe-cutting question, sorry.

 

[turbomaniac]

Some old school mechanic told me that actually the concept of watercooling a turbo is just a safety system for ppl who dont know how to maintain a turbo, meaning running their turbos hard and then shutting the engine off right away or not changing the oil in their cars.
According to this gentleman, making sure the engine idles for a couple of more minutes (at least), especially after a hard drive, and changing the oil on time can give a turbo a long, happy life, just likea watercooled unit.

From my experience: I ran an oilcooled T3 from an '84 760 for 2yrs in an '88 760 . I replaced the turbo when the odometer read 180k. The turbo itself was a rebuilt unit with ~2k on it, that came with a very noice pr tag:: free.
When I sold the car, I told the new owner what to do if he wants long life out of the turbo.
Apparently, he took me seriously. That 760 has presently ~260k and turbo is still going.

 

[Homer]

Aye. Might as well watercool it. I bought a turbo timer as well.

 

[Mueller]

straight from Garrett:

Oil & Water Plumbing

The intake and exhaust plumbing often receives the focus leaving the oil and water plumbing neglected.

Garrett ball bearing turbochargers require less oil than journal bearing turbos. Therefore an oil inlet restrictor is recommended if you have oil pressure over about 60 psig. The oil outlet should be plumbed to the oil pan above the oil level (for wet sump systems). Since the oil drain is gravity fed, it is important that the oil outlet points downward, and that the drain tube does not become horizontal or go ?uphill? at any point.

Following a hot shutdown of a turbocharger, heat soak begins. This means that the heat in the head, exhaust manifold, and turbine housing finds it way to the turbo?s center housing, raising its temperature. These extreme temperatures in the center housing can result in oil coking.

To minimize the effects of heat soak-back, water-cooled center housings were introduced. These use coolant from the engine to act as a heat sink after engine shutdown, preventing the oil from coking. The water lines utilize a thermal siphon effect to reduce the peak heat soak-back temperature after key-off. The layout of the pipes should minimize peaks and troughs with the (cool) water inlet on the low side. To help this along, it is advantageous to tilt the turbocharger about 25? about the axis of shaft rotation.

Many Garrett turbos are water-cooled for enhanced durability.

 

[JohnLane]

We are running turbocharged engines.

We should all be using synthetic motor oil. Synthetic oil will not break down as does dinosaur based oils.

The cooling for the center bearing is mostly for those who will mot spend more then 99 cents for a quart of oil and then do not change it.

I've yet to kill a turbo in any of my cars. My cars all get Mobil 1. I'll keep trying to kill one.

 

[kildea]

just an idea, but couldn't one just separate the oil system of the turbo from that of the engine?

what i have in mind is a stand-alone pump and reservoir, and an oil cooler out in front. this way one could design the thing to continue pumping for x-amount of time after shutting the car off if necessary, and if the reservoir is big enough and the cooler is efficient enough i imagine it would keep things cool.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=BMM-70275&N=700+115&autoview=sku

+

http://store.summitracing.com/partdetail.asp?autofilter=1&part=TIL-40-524&N=700+115&autoview=sku

+

http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX-3818&N=700+115&autoview=sku

+ some lines, etc.



just an idea

 

[Mueller]

just an idea, but couldn't one just separate the oil system of the turbo from that of the engine?

what i have in mind is a stand-alone pump and reservoir, and an oil cooler out in front. this way one could design the thing to continue pumping for x-amount of time after shutting the car off if necessary, and if the reservoir is big enough and the cooler is efficient enough i imagine it would keep things cool.

http://store.summitracing.com/partdetail.asp?autofilter=1&part=BMM-70275&N=700+115&autoview=sku

+

http://store.summitracing.com/partdetail.asp?autofilter=1&part=TIL-40-524&N=700+115&autoview=sku

+

http://store.summitracing.com/partdetail.asp?autofilter=1&part=FLX-3818&N=700+115&autoview=sku

+ some lines, etc.



just an idea

google "turbo timer"

 

[kildea]

no, you didn't read carefully.


i'm not suggesting something equivalent to a turbo timer, rather i'm suggesting isolating the turbo cooling system from the engine altogether.

giving it its own oil reservoir, pump, and cooler.

entirely different.

 

[Forg]

It could be done, but it's a fair bit of extra weight & complexity to achieve the same thing as a turbo-timer will achieve; or, if you're not going to be handing your car to a mindless noob, simply not turning it off hot.

We are running turbocharged engines.
We should all be using synthetic motor oil. Synthetic oil will not break down as does dinosaur based oils.
The cooling for the center bearing is mostly for those who will mot spend more then 99 cents for a quart of oil and then do not change it.
I've yet to kill a turbo in any of my cars. My cars all get Mobil 1. I'll keep trying to kill one.

I think the water cooling is a bit like the oil-sprayers. A "safety" device which gives you a bit more overhead for unusual circumstances or when you're pushing something that bit further than normal; something, hopefully, which you'll probably never actually use the fuctionality of.
Except much much much simpler to implement.

 

[Mueller]

no, you didn't read carefully.


i'm not suggesting something equivalent to a turbo timer, rather i'm suggesting isolating the turbo cooling system from the engine altogether.

giving it its own oil reservoir, pump, and cooler.

entirely different.

I read it....way too much cost and complexity added to it...sure it "can" be done, but there are better methods available.....no reason to isolate it....well, now that I think of it, I do think the company that makes the remote turbo installs use something similar to you proposed setup, but they are mounting the turbo near the rear axle...

 

[kildea]

if you read it then why post a "google it dumb-ass" type remark, in particular when what you actually propose i google is entirely unrelated to my suggested remedy?

forget it ...