PDK 987.2 Overheating Issues
12-30-2014, 11:35 PM
#47
The factory has installed a couple of oil to coolant heat exchangers on these vehicles. They are inadequate for all but the most basic track usage. If you are going to track the car hard or racenit you must add an additional air based cooler.
Furthermore there are two gearboxes. The "open" diff gearbox has a smaller diff. When we designed an LSD for it we were forced to make a smaller LSD. The smaller LSD runs hotter.
If one is serious about building a racecar, spend the extra money up front. Get the LSD version of the gearbox. The LSD for racing we designed is do much more robust and able to better distribute loads and heat. If you are spending 6 figures on a racecar, don't cut corners. Pay a little extra on the front end. The guys who have paid $7500 for a crate LSD gearbox (core exchange) and then had to buy another proper Motorsports LSD have an extra 5 figures in the car. This is not isolated to my LSD. My competition claims their LSD is good to go for your PDK. It's small and will wear out your gearbox, if not overheat things, much more quickly.
Heat is the enemy. Bigger is better and more cooling increases lifespan.
Furthermore there are two gearboxes. The "open" diff gearbox has a smaller diff. When we designed an LSD for it we were forced to make a smaller LSD. The smaller LSD runs hotter.
If one is serious about building a racecar, spend the extra money up front. Get the LSD version of the gearbox. The LSD for racing we designed is do much more robust and able to better distribute loads and heat. If you are spending 6 figures on a racecar, don't cut corners. Pay a little extra on the front end. The guys who have paid $7500 for a crate LSD gearbox (core exchange) and then had to buy another proper Motorsports LSD have an extra 5 figures in the car. This is not isolated to my LSD. My competition claims their LSD is good to go for your PDK. It's small and will wear out your gearbox, if not overheat things, much more quickly.
Heat is the enemy. Bigger is better and more cooling increases lifespan.
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12-31-2014, 07:40 AM
#48
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Is there a need to cool the PDK clutch fluid in addition to the diff oil?
12-31-2014, 08:06 AM
#49
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Hi Mike, I have only seen 1 car before come through here with a true PDK cooler. While this would be the most efficient way to cool the fluid in the PDK which has its own heat exchanger from the factory, it makes me nervous. We removed a tiny bit of fluid from a car and it resulted in needing a calibration. I'm a big fan of leaving that thing alone to work as intended AND "doing everything else." We avoid that cooler but wrap headers, cool the gears and LSD, open up radiators and improve ducting. You definitely want the gears and LSD fluid being cooled but we have had no problems with our approach. Again, the best way to cool the PDK clutch fluid is to run an air-oil cooler directly to it but I'm a HUGE advocate of not screwing with stuff that doesn't need futzing especially when I've seen it get stuck in neutral because of a fluid level change.
12-31-2014, 12:49 PM
#50
This is an interesting thread, I am looking to purchase a 987.2 PDK I can for use as a track car, not race car. Perhaps others can chime in, but it seems like the following order of LSD non LSD would actually help with the PDK track overheating issues, can anyone confirm my assumptions.
Also been doing a lot of digging all over, has anyone actually solved this problem? I don't really see anything the clearly states this mod for x will fix this issue 100 percent.
1. A non LSD car would run the coolest as no LSD heat transfer to PDK clutch side
2. A factory LSD car would overheat more than 1 but less than 3 because its a beefier larger unit?
3. A non lsd car with aftermarket LSD would overheat most as its a smaller unit?
Conclusion a manual with no LSD would overheat least as it cooling system has less to deal with (PDK heat and LSD heat)
Lot of conjecture on my part and hoping for some answers from those that are running any of the configurations I mentioned.
Im not married to any trans yet, so if a six speed has no cooling issues then that for me would be a relatively easy choice.
Thanks much!
Also been doing a lot of digging all over, has anyone actually solved this problem? I don't really see anything the clearly states this mod for x will fix this issue 100 percent.
1. A non LSD car would run the coolest as no LSD heat transfer to PDK clutch side
2. A factory LSD car would overheat more than 1 but less than 3 because its a beefier larger unit?
3. A non lsd car with aftermarket LSD would overheat most as its a smaller unit?
Conclusion a manual with no LSD would overheat least as it cooling system has less to deal with (PDK heat and LSD heat)
Lot of conjecture on my part and hoping for some answers from those that are running any of the configurations I mentioned.
Im not married to any trans yet, so if a six speed has no cooling issues then that for me would be a relatively easy choice.
Thanks much!
01-01-2015, 07:03 PM
#51
Wow.....thanks all, for this discussion. Im with rack henry - i was planning on a 987.2 S pdk to include DE's and stumbled upon this thread. I am really glad i found this info before my purchase. I'm ok doing some modifications - was already planning on seats/roll bar - but it wasn't my intention to have to do extensive cooling upgrades on account of some mid engine design challenges.
Looking forward to any updates. I assume most are much quicker than me (1:47 at mid ohio) but it seems that ANY track driving sessions (that aren't "sunday cruising") above 20 minutes can lead to overheating......is that true?
Looking forward to any updates. I assume most are much quicker than me (1:47 at mid ohio) but it seems that ANY track driving sessions (that aren't "sunday cruising") above 20 minutes can lead to overheating......is that true?
01-01-2015, 09:13 PM
#52
Wow.....thanks all, for this discussion. Im with rack henry - i was planning on a 987.2 S pdk to include DE's and stumbled upon this thread. I am really glad i found this info before my purchase. I'm ok doing some modifications - was already planning on seats/roll bar - but it wasn't my intention to have to do extensive cooling upgrades on account of some mid engine design challenges.
Looking forward to any updates. I assume most are much quicker than me (1:47 at mid ohio) but it seems that ANY track driving sessions (that aren't "sunday cruising") above 20 minutes can lead to overheating......is that true?
Looking forward to any updates. I assume most are much quicker than me (1:47 at mid ohio) but it seems that ANY track driving sessions (that aren't "sunday cruising") above 20 minutes can lead to overheating......is that true?
01-01-2015, 11:54 PM
#54
01-02-2015, 12:24 AM
#55
+1. The cayman is a wonderful car. Few if any mods needed for HPDE. As you push the car to its limits (advanced DE/racing), cooling becomes critical. LSD(PDK), engine, rear brakes, front brakes, all have to be addressed.
01-02-2015, 09:37 AM
#56
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By FAR, this is the best/most popular P-car platform for drivers that I work with at the track, split about 80% club/pro race and 20% DE. Next up are 997 Cups...
A fair number of drivers start with the manual and progress to the PDK, others jump right in. Can you tell I'm a BIG fan of PDK?
Yes, thermal issues do occasionally surface, but they're well known and taken care of in well sorted cars fielded or built by recognized shops with experience in these cars.
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01-02-2015, 11:46 AM
#58
Im pretty experienced 15+ years and raced karts, DE is of no interest TT is my goal and eventually full track. So I will be driving hard off the bat. I do get answers , such as it needs mods. I am doing a cost calucluation and budget, to get the car ready is part of that. Not having hard fixes and hard numbers is not ideal. Reaching out to folks that track these hard, not DE. Should have been more clear..
Regards,
01-02-2015, 11:49 AM
#60
+2
By FAR, this is the best/most popular P-car platform for drivers that I work with at the track, split about 80% club/pro race and 20% DE. Next up are 997 Cups...
A fair number of drivers start with the manual and progress to the PDK, others jump right in. Can you tell I'm a BIG fan of PDK?
Yes, thermal issues do occasionally surface, but they're well known and taken care of in well sorted cars fielded or built by recognized shops with experience in these cars.
By FAR, this is the best/most popular P-car platform for drivers that I work with at the track, split about 80% club/pro race and 20% DE. Next up are 997 Cups...
A fair number of drivers start with the manual and progress to the PDK, others jump right in. Can you tell I'm a BIG fan of PDK?
Yes, thermal issues do occasionally surface, but they're well known and taken care of in well sorted cars fielded or built by recognized shops with experience in these cars.
I know why you're a fan of PDK ( I think anyone who has driven a real sequential and has driven PDK would have to love it!!
, its pretty darn amazing!! My research has indicated that overheating is a known issue, here in SoCal where some tracks are over 100F ambient, this is something I need to have a fix for before I go to track. I am building a track car, not a DE car. 99 percent track right off the bat. Thanks!!