Hatzenbach

track day In Laguna-Seca today with HOD
10 minutes into the session the temps were:

• Oil: 265F
• Coolant 235F

I drove back to the pits, went out for another session with the same results and then and called it a day
On the way home the temps were normal (195 / 185)

Outside tnmp was ~90F
The oil and coolant temps were measured with an AIM Solo-DL connected to the CAN bus
The car is a 2009 C4S
I already have
* 3rd radiator
* external PDK cooler

Any ideas what else I could do?

Don Assaf

What external PDK Cooler do you have ?

CAVU

A few of questions:

- Have you seen these temp levels in the past?
- Any recent servicing, additions or maintenance to the cooling system?
- How old is the water pump and if not factory, what brand?
- What coolant is being used and what is the mix ratio with water?
- How many miles on the engine (if not original) and cooling system?

wjk_glynn

Like CAVU, also very interested to know what you were seeing on previous hot days with the 3rd radiator?

Basically, has something changed?

Thanks.

Karl.

MrMoose

Some good questions above. Also, are your radiators clean? Stuff can get trapped between the condensers and radiators and impact cooling performance.

Since you're in CA where It doesn't get too cold you could try going to 40/60 coolant/water, that'll somewhat improve the ability of the system to remove heat.

Hatzenbach

Forgot where I got it. It was for a Cayman, something like this. https://www.tpcracing.com/product/ra...on-cooler-kit/
But due to the different engine/PDK layouts between Cayman and Carrera it was *not* plug & play

Hatzenbach

engine is original (PDK is not) 65k miles

So probably next step is to replace the water pump and change the coolant mixture?

RonD

My 991 C2S with 3rd radiator would reach 265-270F oil temp at Laguna when the outside air temps were high. And 90 OAT is getting up there. I considered it normal for the conditions. I would do a cool down lap and continue to drive in the pit area until the temp was around 200 before I shut it down.

Frank 993 C4S

It's good to shut down the car at those temperature levels.

Things I would check:
- Are the radiators clear of road debris?
- Do you have radiator screens? Some of the designs are very restrictive and actually increase operating temperatures
- Is the bumper bottom behind the center radiator fully cut out. It can be cut quite a bit (see below)
- Do the operating temperatures go down as you turn the cabin heat on?
- Are you running both radiator fans? If you use the car mostly on the track, you can actually remove one radiator fan.

Some people are using Water Wetter with good results Red Line Synthetic Oil. WaterWetter® (redlineoil.com)

Hatzenbach

Hi Ron, good to hear from you again. Are you making it out to Laguna again anytime soon?

MrMoose

If you look at the Redline data, Water wetter really doesn't do much if you're running a 50/50 water/coolant mix. Which makes sense, the coolant manufacturers add a surfactant of their own.

I guess you could check the water pump, but it's not the first thing I'd suspect. I mean, I've seen some photos on the 9A1 engine where the composite pump vanes had cracked or degraded, but I don't think that's super common. At 60K my OEM pump looked new.

swoardrider

I too was at Laguna yesterday, in group C. I don’t have the CANBUS data logging that you have, but my car ran real hot as well, going off of the dash gauges. Oil temp read 275° and maybe even slightly higher. Water temp gauge is pretty useless, but it did move off the 175° mark ever so slightly. My new Sport Cup 2 Track Connect tires saw as high as 215°. No other track days have I seen these high of temps. My mechanic keeps claiming these temps are fine, but I still have my doubts. I can’t imagine what temps will be like in a month or two at places like Buttonwillow or Thunderhill!

RonD

Hi Chris, Probably not until this fall, I like the cooler temps lol. I will be sure to drop you a note when I do a Laguna day. That would be fun!

Hatzenbach

Ah, yes I was in "C" as well. You have this totally "stealth" black 997.2 GTS with a cup wing - right?
I was in the Riviera Blue 997.2 C4S
Good to hear I was not alone with the high temps

Hatzenbach

I texted with my mechanic while I was at the track and he told me to call it a day if the temp goes over 265~270, which I did
I believe at 275 the oil starts to shear and I don't need a 3rd ride in the cab of a flatbed truck from Laguna back home

Yeah, I won't be going to B'Willow or T'Hill this year for exactly these reasons...