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2011 R8 V10 Spyder 6MT
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Discussion Starter #1
Last month I was driving up a mountain got to the top, parked, and then turned the the car off. A few minutes later we heard a bang that sounded like a backfire, followed by steam coming out of the engine bay. After getting towed home and removing the cover I found the coolant tank had split on 3 of the 4 sides. My tank did not have the metal strap retrofitted to help prevent this from happening. Seeing as this was a colder day (snow was on the ground) and I track the car I wanted a better solution than a strap on the same poorly designed coolant tank.

I bought the coolant tank from the gen 2 cars. This is shaped like a ball, as any pressure vessel should be. It is also smaller so I guess you save some weight (unfortunately I didn't weigh it before I installed it). The coolant level sensor is plug and play on the gen 1 (I had to Dremel the connector on the tank to actually make is snap). The issue is the mounting and outlet are completely different.

I ended up buying some molded silicone rubber hoses to make a couple of tight bends that were required (3/4 inch/19mm inside diameter 180 and 90 degree bends). You have to completely remove the stock hose between the coolant tank and firewall mounted hardline. Once you remove the heat shielding and wire harness support you have enough access to do this. Pictures below on what these bends looked like.

The mounting of the gen 2 tank was the hardest part. I have a spyder, so I didn't have to be exact in the position of the cap. There is just enough room to get it exactly right if you want to spend more time fine tuning the bracket. I kept the tank and hoses are far away from the engine as possible. My process was getting the rough shape done out of cardboard and tape. Then a second cardboard one, but with all of the bends and minimal tape were welds need to be. I then transferred this pattern to a piece of 1/8 inch/3mm aluminum. I was then able to bend it into shape with a hammer and vice. I turned some aluminum spacers for the mounting bolts, but these can be bough from a hardware store like McMaster. Some welding, a lot of sanding, and some paint later and the bracket was done.

I have done some driving on it since and everything seems good so far. I'll report back if this changes. I probably could have avoided this whole ordeal by just letting the car idle after pushing it (I did this at a track day and had no issues on the original tank). If anyone wants to repeat this I would incorporate slots in the mounting holes to help get the position just right. Having access to a welder to tack things in place would have helped a lot as well. Now since the general shape is known, a well equipped shop could probably make something better in a few hours.
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I too thought about this but chickened out.. I figured it wasn’t a bad thing to have a failure point (the coolant tank) which was both easy to change and inexpensive (£50 part) compared to the rest of the system. I might stretch to some reflective tape underneath it as similarly to what you found, I’m convinced it’s temperature change or extremes that kill it.
 

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2011 R8 V10 Spyder 6MT
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Discussion Starter #6
Well the tanks have pressure relief valves built into them with the caps. Ideally that just pops and dumps some coolant without any part failing. That way you can wait for it to cool down, add some water and get home.

The service manual procedures only test the coolant system to 14psi (likely cold). The caps can be tested separately and they are supposed to open between 23-28psi. Seems like poor engineering to me. One of these days I'll have the dealer test my cap and then the whole cooling system to the pressure the cap opens at. This should make it so in the event of overheating I can just add water and call it good.
 

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I’d say there’s a reason the LMS Cars run round ones. Makes sense.

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I’ve got the strap on mine, but wouldn’t mind swapping it out to the Gen2 as well.
Thanks for the write up.
 
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