ATF Fluid with most heat cycle resistance?

[FlyPenFly]

This is for a NC Miata auto-trans (actually it's for a Fiat 124 Abarth but it uses the NC transmission in a different housing).

Redline is not listed here but I believe the D4 ATF is compatible according to their site. Which fluid would you pick if the car will be autocross and tracked every month. An ATF cooler might eventually be installed if temperature becomes a real problem. Fluid will be changed annually and car has 45k miles on it today.

This what RockAuto lists as compatible.

 

[GSCJR]

I'm wondering if a TES-295 fluid would more suited for your application. Maybe @clinebarger can advise here?

 

[MolaKule]

Please explain by what you understand to be "Heat cycle resistance."

Every ATF has thermal conduction and convection coefficients.

Yes, if the temps get too high add an ATF oil cooler in the circuit.

 

[nascarnation]

I'd recommend measuring temps using a heat gun just for interest sake.
Your Allison TES-295 / 668 fluids are going to be robust because of the PAO base.
However you can have issues with heat effect on polymers in the transmission even if the fluid is not breaking down.
Temp data should lead you in the right direction on possible need for cooler upgrades.
But if most of your running is in TCC lock, your automatic may not be making all that much heat.

 

[FlyPenFly]

Please explain by what you understand to be "Heat cycle resistance."

Every ATF has thermal conduction and convection coefficients.

Yes, if the temps get too high add an ATF oil cooler in the circuit.

Track temps frequently overheat ATF which requires giving the car a longer break between sessions. When the heat gets high enough it causes some breakdown of the fluid.

 

[97prizm]

This is for a NC Miata auto-trans (actually it's for a Fiat 124 Abarth but it uses the NC transmission in a different housing).

Redline is not listed here but I believe the D4 ATF is compatible according to their site. Which fluid would you pick if the car will be autocross and tracked every month. An ATF cooler might eventually be installed if temperature becomes a real problem. Fluid will be changed annually and car has 45k miles on it today.

This what RockAuto lists as compatible.

View attachment 291272

Is it a six-speed automatic? Torque converter or dct?