NOLA_70002 wroteThere is no magic solution for an overheating S65 engine....well, at least not a simple one appropriate for a streetable M3. If you want to do dry sumps and/or run coolant lines to larger coolant reservoirs in trunks, then yeah, I guess you can have a magic solution. But no street M3 is doing that stuff. Stuff like oil diverters, bigger coolers, misting systems.....these are the "normal" tools at our disposal.I am not sure if the epic oil diverter is the magic solution to reduce the oil temp.
NOLA_70002 wroteI can and do run 20 minute HPDEs. And the car runs those laps at a good pace---faster than any moderately prepped M3.The oil return port is poorly blocked by the compressed spring.
The data posted by dogbone shows that the diverter valve mod is just prolong the heat soak and give us few more laps.
So, for TT runner, it could be good.
But for anyone who typically run the full HPDE 20min session, this is not going to help.
The setup of a car has a lot to do with how much you overheat the engine. If someone runs 200 treadwear tires, has stock power, no aero, no race pads, I would say that the car isn't going to overheat quickly---if at all. Adding performance parts like high grip tires, aggressive brakes, aero, etc......these things make a car overheat far more quickly.
Also, weather plays a big part. On a 50º day, a car runs great and can go forever. On a 109º day, the same car puts in lousy times and can overheat quickly.
The AIM data indicates that there is less build up of heat per lap with the oil diverter. I'll take that! Let's put it this way is anyone else posting any kind of truly actionable data that shows that some other solution is better? If someone is willing to share a great cooling solution and post real data, I'm happy to listen.
Getting a few more laps in an HPDE is all you need to get through the 20 minutes. If you were getting 3-4 laps and then overheating, and then you can get another 3-4 laps----let's say the laps are around 2 minutes, and that's 7 hot laps on average, plus a warm up and cool down.....you're over 18 minutes. Sounds like a job well done!
And really, isn't pretty much ANY passive cooling solution like a bigger cooler or an oil diverter just trying to prolong the amount of time it takes for the heat to set in?----Trying to make it so that you simply stop driving the car before the heat is a session-ending problem? Now, something like meth injection is different. But running meth is a solid commitment, and you better not run out!
It's also worth mentioning that no car can run at 100% MAX pace doing laps around a road course-style track for 20 minutes, and it's not because of the engine----it's because of the tires. The tires need a break regardless of what level of motorsport you play in. And the heavier the car, the worse it is. So, regardless of what an engine is capable of, the tires will always be a limitation.
Anyway, the oil diverter is only $80, but it takes 4-5 hours of labor to install. So it's not the cheapest mod if you have to pay for labor. (My shop installed it). Was it worth it? For me it was, but I don't think it was magical.
