Rb25 R32 Overheating

[The WOR57]

Hey guys - got a dedicated track car - its got forged rb25, oil cooled Master Power GT35R, oil cooler etc etc.

The cooling system comprises of a Greddy 52mm Radiator, 2 x 16" Thermos, Nismo Thermostat, vented bonnet.

Now after basically one hard lap of the track its sitting on 210deg F, after 4 or 5 laps, its on 260deg F - however it has never boiled on me yet. If i let it sit for like 1min after its on 260deg F, temps drop back down to 210deg F.

I am at a loss as to why it keeps cooking - if it was head gasket would it recover so quickly? I haven't compression tested it yet. My mate thinks its my gauge that is faulty - but its a brand new Stewart Warner with new sender etc - all wiring is secure and earthed properly.

I'm mid way through the AU Falcon thermo fitment - I'd like to return the clutch fan to the engine bay but my "whizbang fabricator" has run my I/C piping in a what that does not allow this.

[The WOR57]

I should add that it doesn't use a single drop of water, and theres no residue or trace of oil in the cooling system

[trel]

what sort of thermostat you using? could you possibly try using one that opens at a lesser temp?

[heller44]

Ducting through from the front bar to the radiator? ie rad guides. might be an option.

[The WOR57]

Nismo Thermostat - i forget the temp - was the lowest temp one i could get

[blind_elk]

You need to create a low pressure area behind the radiator - try some bonnet flutes / vents.

[DaGr81]

I reckon it's the thermos, so I've read many times that if not set up correctly they are worse than the clutch fan, try with the clutch fan and see what happens

[The WOR57]

You need to create a low pressure area behind the radiator - try some bonnet flutes / vents.

Vented bonnet is already fitted

[blind_elk]

Then you need to make sure the air wants to pass through the radiator, not down and out under the car.

[The WOR57]

its got full alloy bash plate covering from radiator support to steering rack basically