orthojoe

This is a bummer, Bill. There's got to be some other CRs with PDK out there that track their cars who can chime in. I still feel that there has to be something wrong with the coolant system. Why would a CR and spyder with PDK have such different cooling capacities? It doesn't make sense to me. I can vouch for Ben and confirm that he is a GOOD driver, so it's not like he's a pansy at the track that doesn't push the car.

Why would running PDK cause the engine coolant to overheat?
Ken makes a good point about the mesh covers. Before you give up on the car, try one coolant flush/fill just to make sure there's no air in the system.

Dr.Bill

I do have the grill mesh. I also had it on the Spyder with no issues.

The plan is to take off the grill mesh and have the dealer flush the coolant. I'll give it one more shot before looking at something else. I never had an issue with two different 911 PDK cars or the PDK Spyder. Wonder what is different with the Cayman? Is this just the R or do the base and S versions suffer as well?

Of course, I was chasing and passing 997 C2S's last weekend. Maybe another 'feature' to keep the Cayman from out-performing the 911. LOL

JSF101

I have a 2.9 Cayman w/PDK
added 3rd radiator as a precaution
regularly track it with no problems
to be fair, I do 30-45 minute sessions and go home
last summer was a scorcher here in TX and my car survived just fine but I was seeing some temp increase so I added the 3rd radiator for insurance
guess this summer will tell if it makes any difference

orthojoe

That is so weird. Why would it be problem with only the Caymans? Any guesses?

orthojoe

Where do you add a 3rd radiator? I thought PDK equipped cars came with a 3rd radiator (for the tranny) already?

JSF101

seems they change their mind every year or two

my 2010 Cayman did not have a center radiator
friend just took delivery of a 991 Carrera with PDK, no center radiator

bensf

Bill, I have another data point for you. I was at Thunderhill yesterday and got a coolant temperature reading through the OBDII port as I was coming off track after a 20 minute session. I was able to go at full clip for almost the entire session in Sport + mode due to very minimal traffic. It felt hotter to me (mid 80's) but according to the vehicle thermometer, the ambient temperature was 78 degrees. Coolant temp was 212 but of course the dummy gauge in the car read just a tick above 175. I have the PorscheMesh radiator guards installed as well.

I can't imagine that our cars are that different. I think theres got to be something going on with your particular vehicle. I hope this gets sorted out for you so you can go back to humbling more 997 drivers

Dr.Bill

Thanks Ben.

I took my mesh grill guards off today. The dealer is going to take a look at the car next week. The coolant level was low when I looked this morning.

However, they are getting in a nice 2011 C2S with all the right options, so the problem may be solved. . .

fhp911

OrthoJoe says
It ISN'T restricted to Caymen. I have a manual transmission '11 Boxster S. I ran it on numerous track days last summer without problem (temps in the 80s and 90s.)

Then I had an event with temp of 103. On each of the 4 sessions at the 11 minute mark, the temp needle would go deeply into the redzone. I would park the car for the rest of the session.

Over the winter I had a 3rd radiator installed in the provided spot between the other 2, as in standard on PDK cars. note: this is a water radiator for the engine, not a gearbox radiator as speculated by OrthoJoe.

It hasn't been hot enough for me to know if my new 3rd radiator cures the problem but I'm optimistic.

orthojoe

Hmm... I dunno Bill, with you coming off of a spyder, GT3, and Cayman R, I would think a plain Jane 2011 C2S would seem kind of boring.

f4 plt

Ray, I posted on another thread about my temps with the third radiator on my 2010 Cayman with PDK. Before I put the third radiator on i was getting 225 plus in our hot Texas Summers ( I track with JSF101) but now it stays right at the idiot gauge 175. Speaking of gauges I removed but did not disconnect the sport chrono clock, careful wrapped it in foam and tie wrapped it inside the dash and in its place in the wart I put a real oil pressure gauge on both my Cayman and the spider. Great to see real oil pressure at all times.

By the way I run in Sport not sport plus mode

2slow2speed

Just curious if the coolant temp issues were resolved.

the_vetman

As someone else mentioned, this is not just a Cayman problem but a 987 problem. Mid-engine 987's run incredibly hot under the "hood" - just ask any ITC racers.

With PDK, the gear oil will also get incredibly hot when driven aggressively on the track. Well, OK, this is not a PDK-only problem but PDK compounds the problem in short DE sessions. Gear oil has been known to get as hot as 400 degrees in MT racers. Most use transmission coolers now. BTW, Matt from GT said that transmission coolers (non-PDK) are only necessary for racing - not really needed for 20-30 min. DE sessions.

911's are less prone to problems since they're not mid-engined and have better air flow compared to the current 987 set-up.

I have a MT but do not use any grill mesh. Reason? I'm concerned that any mesh would disrupt airflow to the radiators (though this is in relation to the engine and not transmission cooling). With PDK, the engine is also more likely to overheat because it keeps the revs above 6,000 in Sport Plus mode at the track.

Hope this helps (though I think Dr. Bill may have decided to get rid of his R).

Dr.Bill

Well, it was certainly better. I made sure the coolant was full and added one bottle of water wetter. Also removed the grill mesh.

One track weekend after the above with ambient temps a few degrees lower than when I had issues, so that may have helped too. Only 88 - 90 instead of 94 - 95 out. The temp did move away from the standard 175, but only to 185 or so. No temp warnings.

Still have the Cayman R. Not much else in the price range that handles like this. I'm on a list for one of the new R8's, but that will depend on the price.

orthojoe

Hot track day at Laguna Seca today. Ambient temps in the mid-90s. I logged a peak coolant temp off ECU of 230. Yikes.... (dummy gauge needle only slightly past 175... double yikes)