[Compelica]

Some tidbits of info on a low thermostat on our FA20s by Andre from HP Academy:

"First of all, in terms of the thermostat temperature or the cooling fan. Yes the engine will be more prone to knock or detonation as I've kind of touched on. When the engine's operating temperature is higher. It's all about that combustion temperature. So the trend that we're seeing a lot with a lot of late model cars now is to run a very hot thermostat, perhaps as high as 92 to 95°C, you'll have to convert that into Fahrenheit sorry, my brain doesn't work in imperial.

But that's to aid fuel economy. However that hotter operating temperature does definitely make our engine more knock prone and on engines that are already knock prone, it can make our job tuning the engine a little bit more difficult. This is something I found on our Toyota 86 with the FA20 engine, the stock thermostat on hat is 92° and I dropped that down to an 82° thermostat and found that I did get an improvement in the engine's ability to take timing. One thing, without trying to get too involved with this, one thing that you do want to watch is it's all well and good if your operating temperature on the dyno is perahps 80 or 82°. If however like I see with our Toyota 86, the engine temperature creeps up to 95 or even 100° out on the racetrack, that's the situation we really need to be tuning for and being careful of so you do need to be aware of how the engine coolant temperature may affect the car once it's off the dyno."

https://www.hpacademy.com/previous-w...link-g4-vipec/