Other Areas 

This section is random, but covers the stuff I could not fit anywhere else. 


Engine Oil


After endless debates both offline and online, Gspeed from the FT86 forums posted this excellent thread that shares data he has captured on engine oil degradation in relation to temperature. 


As my car is setup for sprints rather than longer races, I have chosen not to install an oil cooler. Monitoring oil and water temperature becomes crucial and is done with my Pivot DPW gauge mounted in the driver's side air conditioning area. 




Once my oil temp hits 265f (130c) or my water temp hits 225f (108c), I will back off till it reduces to 210f or 100c before I start my next run. 

Best Motoring ran an endurance race a number of years ago which demonstrated how professional drivers manage oil, water and cabin temperature in different ways. It is a good resource to understand the stresses a car and driver goes through lap after lap. 


One compromise I have considering is to add a water to oil cooler kit. This basically revolves around creating a pathway for the oil to be cooled by the radiator, and is an OEM feature of FA20DIT Subaru Forresters. Tested results of such as setup will be around 10% lower oil temp, 5% higher coolant temperature, and faster warmup. These results will be negated the harder and longer a car is driven, so it is not a replacement for a dedicated oil cooler for hard use track cars. 



The stock FRS/GT86/BRZ flywheel weighs 9.45kg. While much has been written about the improved engine response and free revving nature of the lighter flywheels, less has been written about the compromises that they bring. 


Without getting technical, the flywheel does not add power to the car, it just makes the time taken to get from one rpm point to another shorter. Ideal for a race track, tiring day to day. 

Stock flywheels are designed to reduce noise, vibrations, and harshness (NVH), and the lighter you go, the noisier they get. Check out this video of one of the lightest flywheels available (prolite), to get an idea of what this means. 


After much consideration, I have decided to go with the Toyota TRD flywheel. As this car is being built for response, it should be ideal. Even their official website warns against the harsher nature of this part, but I think it should be the best current compromise. 



Alternator, Crank and Air Conditioner Pulleys


Toda is a well respected Japanese racing company that produced a lightweight replacements for the alternator, crank and a/c pulleys that shaves 2kg. Most of that weight savings comes from the crank pulley and I was skeptical of their claim of a 3-10hp gain throughout the power curve. After installing them and tuning the car, I can verify that they were correct, and am extremely happy with the result.