lee101315

After a quick search, I found 100s of posts debating and speculating on whether to leave the turbo water cooled or not. In my past 6 years of owner ship, Ive run both setups, but on the street. Track temperatures and stress is far higher than street. ( but we already know that )

I am getting serious about tracking/autoxing my 951 now, and more and more its becoming better suited for the track than the street ( high spring rates, many fiber glass panels, no AC or interior, etc )

So for the people who actually have been tracking their 951s, are you guys using the water cooled system or not? After installing a bigger oil cooler and intercooler, I guess anything that would keep the turbo temps down would help. If you are, is it increasing your turbos longevity?

I also enjoy the simplicity of not having that stupid coolant crossover pipe in the way, and less hoses to blow up.

95ONE

It's goes without saying, in my circle of friends, that you water cool it, and never disconnect it.

Van

The #1 goal for a race car should be reliability.

To that end, I'd have to think water cooled it better.

jerome951

My stock cooling system is still in place and I have no plans to remove it. 130k miles on the car and I think still the original turbo. Last 30k miles have mostly been track.

The turbo itself gets absolutely freakin hot on the track and anything you can do to keep it cool(er) has to help.

87944turbo

I agree 100%. I have always viewed this as keep it as simple as possible.

I think water cooling probably is better from a longevity standpoint. Just look how durable the stock KKK turbos are at stock boost levels. Is part of that due to water cooling, and the after shut off pump, probably, but who knows how much.

On the other hand, there are MANY oil only cooled turbos out there in the world. Even if the life of my oil only cooled turbo is shortened by 50% (rough numbers here), so lets say I will only get 50K out of it. Since my car is more or less track/weekend, I bet I wouldn't hit 50K in the next 20 years. And in ten years there will probably be some other turbo I want to try out (if I still have the car by then). And if I really wanted to, I could sent it out for a rebuild and be worry free.

So for my track/DE oriented car it's oil only. Ripping all that extra stuff off was a great day!

86 951 Driver

Keep it water cooled. I would maybe even run a bigger oil cooler if your tracking the car.

lee101315

Yes, I will be keeping the water cooling system for the turbo

As for the oil cooler, im using one from a 1993 968 which is double the size of the 951.

Ive never upgraded an intercooler on a street car, but in this case, I'll most likely be welding two 951 intercooler cores together.

rlm328

I will go against the grain. No water on mine, just oil. Water temps are high enough without adding the heat from the turbo. I just replaced my turbo due to vane damage and due to improved technology in the new turbos. The turbo had 5 years of track usage, the bearings were still in good shape.

ausgeflippt951

My turbo is water cooled. Goes without saying these engines get hot.

That said, the previous owner removed the water pump that circulates water after the car is off. This I don't really see the point of, if you're tracking the car. I always leave my car running for ~10-15 min after coming in from a session and this does way more than the electric water pump ever did.

On my previous 951 (stock) I actually spewed water all over the place when, after driving the car hard at the track in 100+
degrees, the water pump started circulating water thru the red-hot turbo. All this did was superheat the water and cause my reservoir cap to blow off.


Either leave the car running after seasons or install a turbo timer to do it for you.

pontifex4

+1 on leaving the car running. My car came with a bad electric turbo water pump, so I got into the habit of idling the car until the fan turned off after coming in from a run (normally for well under five minutes with the hood popped, but our weather up here rarely gets above 80F). I kept a failing turbo going for two years and around 40 track days like that before replacing it and the pump this winter.

mtnman82

ausgeflippt951 , pm sent - question about the spewing water comment, as I seem to be having the same issue ...

Bri Bro

I just got a used turbo that only had only oil cooling. I always run the car for several minutes before turning it off and I really have noticed that the oil temps went up a little and the water temps went down a little on the track. So far, no problems but time will tell.

lee101315

So does that mean the water pump doesn't circulate water through the turbo while the engine is running? I thought when the temp sensor on the coolant pipe was activated, it turned on while the engine was running as well.

400hp944

Keep it wet and get a big oil cooler!

Bri Bro

Once the turbo thermostat opens up, it gets water all the time from the engine water pump. The small turbo water pump turns on when the water at the turbo exceeds a certain temp or you shut off the engine. That allows circulation while the engine is off as long as the temperature is above the turbo water pump sensor set point.