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Hi Folks, I've recently taken delivery of my new to me 2006 CS turbo. seriously loving the car so far. Just wondering about cooling down the turbo after a drive by allowing the car to idle for a while before switching off the engine. is this something which is particularly recommended for the TPC turbo kit / anyone here regularly practise this please? my vehicle is fitted with an intercooler so wondering if this is required. thanks folks!
 

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We are very happy to hear that you are enjoying your Cayman Turbo! When you go out and drive the car hard, you can let the car idle for a few seconds before turning off the engine.
 

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The turbo causes the generation of a lot more heat than in the stock engine and with our intentionally innaccurate temp gauge temp gauge that shows 175 deg for any temp from about 170 to 210, you don't know exactly how much heat is in the engine and system.

When I street drive, I don't bother with cool down. I figure the no-boost time for maneuvering through my neighborhood to my garage or finding a parking place while out is cool down enough.

On track, after each session, I drive around the paddock for a few minutes then stop the car and let it idle for perhaps 10 min while feeling the temperature of the air being sucked through the radiator. I can feel the difference in air temp as the car cools, even though the temp gauge never moves. When it seems to have cooled down, I turn the car off. I am going to start monitoring radiator temps with my IR pyrometer to get some data on cool down.

So, while the turbo itself does not require cooldown, allowing the car to cool after a track session is a reasonable thing to do.
 

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I too love my TPC turbo, and am also concerned about operating temp and cool down. Sebring last weekend was VERY hot. Has anyone fitted a separate temp gauge with the sensor somehwere on/along the intercooler to get some real temps??
 

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I'm not sure what intercooler temp is going to show. The intercooler temp is going to be somewhere between the temperature of the compressor air and the cooling water that is circulating through the third radiator.

If the outside air is about 90 deg F and you are operating at 4psi boost, the temperature of the compressor output air is about 140 deg F. At 6 psi, the compressor exit temp will be about 170 deg f. The intercooler takes a bunch of the heat out which is exchanged with air in the third radiator. I do not know the resulting temp of the intake manifold air, but it is definitely somewhere between compressor output and ambient, which is about all I can say about intercooler temp.

The bottom line is that I get off the gas and try not to command any boost as soon as I see the checkered flag and use the rest of the lap to cool down. I think the turbo itself cools down rather quickly because it has cooler exhaust gas going through the turbine and the intake air flowing through the compressor is not being compressed at all, so is a good cooling agent.
 

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Good point, and I really don't have the answer, as I am for sure not a turbo expert. But obviously somehow we would have to establish optimum operating temp before the info I suggested would be of any use. Maybe the intercooler system is not the correct place to check temps. But is a source of concern, especially down here in florida, so it would be nice to have some sort of monitor on it.
 

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I'll take some temps this weekend at Roebling Road. With my setup, I am very concerned about engine temps, especially oil.
 

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I would offer this bit of advice, if you push the car hard, and get the turbo to generate a lot of heat, and then just turn the car off, the oil will turn to ash, and the turbo will have to be either replaced or rebuilt.

This is called 'coking' the turbo, and I did it to a twin turbo system just pushing my car around town real hard, not even driving on a race track.

Take heed, and just remember to let the oiling system cycle through the turbo until it has reached a more typical idling temperature.

One alternative that some turbo owners go for, is a post shutdown oil circulation system.
 

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Also, with regard to intercoolers, they have NO EFFECT on the temperature of the oil in your car. Intercoolers are meant to remove heat from the intake CHARGE AIR in order to make the intake air more dense, and less likely to pre ignite once in the cylinder. If you get preignition, your engine will go boom.
 

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Good point about coking. With the TPC installation, the oil is circulating as long as the engine is running, so I believe that the cool down that involves running the car for 5 to 10 min will allow the turbo to cool down enough so that it does not cook the oil. I'll let my car idle until the fans go to low speed ( about 205 deg, if I remember correctly, On the up side, I think they go from low to high at about 212 deg.) I think they turn all the way off at about 185. And the whole time, the temp gauge points at 175.

I'm really into heat rejection considering that my setup is putting nearly twice the energy into the system as stock. I have already done a fluid exchange in the intercooler recirc system to reduce the antifreeze to about 15% and put in a bottle of RedLine Waterwetter which decreases the surface tension of water and increases the heat transfer efficiency. 15% antifreeze will protect down to about 17 deg F and since I live in SC (in southern SC, to be precise) and my car is always garaged, I don't think I am taking a risk. And if I start noting heat problems with the main cooling system, I'll do the same thing.
 

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Phils65, I just noted that you are down under, so be aware that we yanks are still using the Fahrenheit temp scale, but I think you know that. Some things to consider with you turbo. First: oil change frequency: as jabo correctly points out, turbo coking is an issue that one must keep in mind. For normal or track driving, change the oil every 3,000 miles (5,000 km is close enough). Second, check the fluid level in the intercooler reservoir every month or so. I can send you pictures of how to do it and I am trying to find time to write an article on the subject. Other than that, not much to do except enjoy.

Cheers
 

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Discussion Starter · #12 ·
Thanks for the warm welcome & advice folks. Sounds like it won't do any harm to let her idle for a bit after a spirited drive so that's what she'll get!

Kenny, if you are able to send any photos through as to where to check the inter cooler fluid I would be most appreciative.

Many thanks!
 

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Sure, here goes.

First, make sure the car is cooled since you will be working in the vicinity of and contacting the exhaust pipe.

This first pic shows the intercooler looking straight up from the bottom with the rear of the car to the left and the centerline of the car toward the bottom of the image. The coupling on the bottom of the tank is the recirculating pump feed line. The service port is on the upper aft end of the reservoir



The next picture shows the fill port. It is on the upper left corner of the aft end of the reservoir. This view is taken from directly to the right of the vertical exhaust pipe leading to the exhaust tip.



I'm sorry I do include a picture of the plug, but it is a brass female hex. It is American, so it takes a 3/8 hex, but a 9mm will work nicely since it is a low torque installation. There is not room to use a 3/8 drive ratchet with a hex socket, so the good old manual key works. I actually had to cut my 3/8 down because it was about 5 inches long and would interfere with the exhaust pipe. The 9 mm has just enough play to prevent mandatory cutting but rubs on the exhaust pipe.

Finally, here is yours truly filling the port. The bottle I use is from a pharmacy and is used to humidify medical oxygen in home applications. I just run it backward after trimming the very small air ports off of the bottom of the center hose. Lung power is plenty to force the fluid up into the reservoir port but less exertion is required the higher you can lift the bottle (the old density times height equals pressure relationship). Fill the reservoir to overflowing, reinstall the plug, and you are done.




Why is the fluid red? The picture was taken while I was putting Water wetter into the reservoir. That was after several cycles of siphoning water-antifreeze mixture from the reservoir, fill with distilled water, run the pump for a minute, then repeat the cycle. I did this to reduce the ratio of antifreeze to water because WaterWetter, according to the company, gives better cooling with lower concentrations of antifreeze.
 

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I took some center radiator temps. In low boost after a 20 minute session, the center radiator was 113 deg with ambient being 87. After a 20 minute session in high boost, the temp was 121 with ambient of 88.

I ran high boost because there was a guy there in a vette Z06 that he had done some work on and said dyno'd at 578 at the wheels. In low boost, the cars were nearly exactly even. Going onto the front straight at the same speed, I would stay with him until about 2/3 down the straight when I would just begin to gain on him. He had the same impression when I was in the lead: I would start inching away in the latter parts of the straight. In high boost I would lift slightly when following, but when I took the lead, I would generate about 3 car lengths of lead on the straight. He also stated that in the short straights between turns that I would extend on him every time.

I did not have any overheat issues. The radiator fans would come on in the low range maybe a minute after I stopped the car. They would blow in low range for several minutes and then turn off.
 

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Good info, thanks. Aggravating z-06's is one the best things about the TPC turbo :).

What psi are you running the turbo at - low to high?
 

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6 psi is low boost, 10 psi is high. The performance difference is noticeable, but not dramatic. The biggest perceptual difference is in long accels. Low boost is a constant pull. High boost pulls harder as RPM increases.
 
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As others have mentioned, you definitely want to let the hot oil in the turbo circulate out of the turbo before shutting it down after some hard driving. You could wire in an HKS turbo timer if you wanted and it would determine the amount of time the car needs to continue running once parked, if at all, and then shut the car off for you. I'm not sure if/how it would work if you have the convenience package though. Also, if this car has an electric oil pump(I'm still learning about the platform), I'm sure there is logic somewhere in the can system or dme that could be modified to keep the pump running for an extra minute or two after shutdown.


Hi Folks, I've recently taken delivery of my new to me 2006 CS turbo. seriously loving the car so far. Just wondering about cooling down the turbo after a drive by allowing the car to idle for a while before switching off the engine. is this something which is particularly recommended for the TPC turbo kit / anyone here regularly practise this please? my vehicle is fitted with an intercooler so wondering if this is required. thanks folks!
 

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has anyone hooked up an egt gauge, an iat gauge, a separate oil temp gauge(if the stock is inaccurate) or even a temp gauge for the transmission? It looks like there is most likely a ton of heat being added to the engine and trans oil from the turbo.
 
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