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TPC racing in Jessup MD replaces the stock heat exchanger with one from a Gt3. They also offer an auxiliary cooler for the PDK. 270+ oil Temps are common for PDK 981s at the track. I start paddle upshifts when I see 260.
This was my first event so 260F didnt bother me much but let me see how it does on different tracks, tires and ambient temp. With PDK I really dont see why allowing the car to shift gear by itself .... so easy ... the car can be smart but on this case the driver can make a better decision and avoid higher revs where not required.
This was my first event so 260F didnt bother me much but let me see how it does on different tracks, tires and ambient temp. With PDK I really dont see why allowing the car to shift gear by itself .... so easy ... the car can be smart but on this case the driver can make a better decision and avoid higher revs where not required.
Agreed, I'm not saying 260F is going to destroy the powertrain, especially for those who won't only track their car a few times a year. I wouldn't be comfortable living at 270F for any extended period of time if I tracked the car often, however. I know alot of Clubsports race at these temps and above, but how concerned are alot of those owners really? I'm my situation this is a rental car that only sees heavy track use and I intend to keep it past engine or pdk failure, which I'm hoping is years down the road, thus longevity is important. I think one of the biggest impacts on longevity for the engine and the PDK is excessive heat. From what I know about these cars, keeping things close to 250F is ideal. Obviously the cooler the better but I don't think getting temps much under 250F is even feasible with hard use.
Regarding the PDK, I prefer to shift manually myself, but surprisingly the vast majority of renters in the car keep it in auto. I know some racers who keep their Clubsports in full auto as well...
If the radiator doesn’t do enough, I will consider the PDK cooler. It still is in a hot area, but is way bigger than stock. Figure “more cooling” can’t but help the PDK cooler, if it doesn’t help on its own. My local track is mostly turns, so not much full throttle as some.
Saving for a GT4, prefer to put my money towards that than more bits on what will ultimately be my mountain road car. But don’t like excessive heat on a PDK.
BEHOLD... I was able to shoehorn a 991 Turbo/GT3/GT4-sized radiator into my humble Cayman S. Used all OEM parts minus the CSF 7068 radiator. And yes it does vent the air downwards through the appropriate cutouts on the front spoiler/lip.
I think it looks a bit goofy right now since the center radiator is so much shinier/cleaner than the side units. But I'm sure some miles will fix that.
Right now there is no center shroud. That is the one OEM part that will not fit directly on. It looks like its feasible to use a dremel on the stock plastic center covering to fashion a shroud but I'm going to leave it for now.
I was able to shoehorn a 991 Turbo/GT3/GT4-sized radiator into my humble Cayman S.
I don't think I've ever seen coolant temperature readings above normal operating temperature with the standard 3rd radiator, even in ambient temps over 100F, so I don't think the system cooling capacity is an issue. So, I'd be surprised if this provides any value.
Make sure you're getting proper airflow directed through this radiator. The OEM shrouding forces all the incoming air through the radiator. If you're not forcing air through the radiator, it won't cool efficiently.
I don't think I've ever seen coolant temperature readings above normal operating temperature with the standard 3rd radiator, even in ambient temps over 100F, so I don't think the system cooling capacity is an issue. So, I'd be surprised if this provides any value.
Make sure you're getting proper airflow directed through this radiator. The OEM shrouding forces all the incoming air through the radiator. If you're not forcing air through the radiator, it won't cool efficiently.
I examined the set-up pretty thoroughly. There seems to be nowhere else for the air to effectively pass through besides through the radiator and out the bottom cutouts.
As to whether theres a benefit to having a larger radiator I'd agree the difference is most likely marginal in most use cases. But the total cost was just about the same and I didn't like that the standard 3rd radiator utilizes less than half of the available real estate of the center bumper opening.
BEHOLD... I was able to shoehorn a 991 Turbo/GT3/GT4-sized radiator into my humble Cayman S. Used all OEM parts minus the CSF 7068 radiator. And yes it does vent the air downwards through the appropriate cutouts on the front spoiler/lip.
After installing the S/GTS-sized CSF center radiator I notice the studs were already in place to mount the larger GT3/GT4-sized center radiator. I wish I had done this right away as the OEM 3rd radiator is pretty small and only helps a little.
Originally Posted by ledbette
I don't think I've ever seen coolant temperature readings above normal operating temperature with the standard 3rd radiator, even in ambient temps over 100F, so I don't think the system cooling capacity is an issue. So, I'd be surprised if this provides any value.
Our coolant temp drops weren't as significant as I had hoped based on Can data (not the dash readout), but it certainly still helped. We also switch to 80% water and 20% coolant, which has also helped drop temps a few more degrees. The coolant system helps cool everything else, so the lower you can get coolant temps/increase deltas, it will help everything else. The real trick is getting hot air out of the engine bay...
Originally Posted by nhnguy12
I examined the set-up pretty thoroughly. There seems to be nowhere else for the air to effectively pass through besides through the radiator and out the bottom cutouts.
As to whether theres a benefit to having a larger radiator I'd agree the difference is most likely marginal in most use cases. But the total cost was just about the same and I didn't like that the standard 3rd radiator utilizes less than half of the available real estate of the center bumper opening.
Your efficiency will drop without having proper ducting to the radiator, but the larger size will also combat that a little bit.
I think the next area I'll look into if I still feel that my oil temps are too high is a larger oil cooler. I think there are definitely diminishing returns on the radiator side of the cooling system at this point.
I examined the set-up pretty thoroughly. There seems to be nowhere else for the air to effectively pass through besides through the radiator and out the bottom cutouts.
As to whether theres a benefit to having a larger radiator I'd agree the difference is most likely marginal in most use cases. But the total cost was just about the same and I didn't like that the standard 3rd radiator utilizes less than half of the available real estate of the center bumper opening.
Congratulations on fitting the oversized CSF center radiator in your CS. I installed the standard size CSF aluminum radiator in my CS and was impressed with it’s quality. Let us know if you are experiencing lower oil temperatures.
I joined in on the discussion mainly on posts #31 and #34 above when you were planning your larger center radiator upgrade in February. I felt that the weak link with the larger 21”x7” GT radiator was to provide sufficient venting through the 4 small bottom cutouts that only provide about 29 sq inches of opening. The OEM center radiator is 15”x7” (equals 105 sq in) and the larger GT radiator equals 147 sq inches with either venting through the same 29sq inch bottom cutouts. We’re you able to add additional cut out openings or increase the size of the original marked 3-1/4”x2-1/4” vent openings to create more venting for the larger radiator?
I agree with ledbette about forcing or pressurizing air through the radiator with a shroud to force it through the small vent holes. If you are seriously concerned with coolant temperatures the two OEM side radiators could be upgraded to the CSF radiators that claim to be 20% more efficient than the OEM radiators and also have cooling fans that will move a lot of air through the radiators. I know that a larger oil cooler will lower the oil temperature but the more you can lower the coolant temperature the lower the oil temperature will lower.
Jim
I had a track day this past Sunday at Street of Willow, so I did the install of my third radiator from Suncoast on Friday which took about 3 hours. I have taken the bumper off before so knowing that really speeds up the 3rd radiator install. I did what some have done is what I would call 'Quick Change', yeah! Change it quick or you will loose more coolant. I lost around 12-15oz with this process (8 on each side).
Here are the parts I received and some hardware I could not figure out where to use them
My Cayman S is PDK and the center intake ducted to the side radiators which requires a new set of side ducting, which I did not want to buy. I just installed thin fiberglass plates to block the ducting instead.
Are you going to leave the lower lip black or paint it back body color? The reason I ask is that I have a 2016 Guards Red Cayman S with some rash on the bottom lip. I think it actually looks better in black like the base has it and thought of replacing mine with a black one. It matches the rear where you have the black trim on the lower portion and looks more GTS like in a way on the front.
Hi guys, just made an account on here after reading this interesting thread. I am in the market for buying a 981CS, and plan to track it fairly regularly over here in the UK.
There was a post earlier in the discussion from @okie981 where they mentioned later versions of the car (possible 2014?) possibly had an upgraded PDK cooling package? Does anyone know anymore about this? Just wondering if it's worth me spending a bit more on a later car if there are some important upgrades that Porsche made?
08-25-2022, 06:03 PM
