Sounds like you had a great day.

If you are using a stock radiator, there is your problem.
 
Time to update to a thicker core, and monitor from there.

I like the direction you are taking with this whole project.  All looks very good.   The original brass radiators are very good but may benefit from a proper rodding-out recondition or recore.   A pressure test of the cooling system both cold and as you are driving it hard can sometimes reveal interesting results.  What coolant and what ratio of mix are you using?  Also could the supercharger drive belt be effecting its wrap round the waterpump pulley at higher RPM? Wish you well with it and keep us posted .

Ah Charlies old car. Had the pleasure of going for a spin in that.
 
Love the flat torque curve, perfect setup for the chassis.
 
Great to hear you will be tracking this car, please keep the updates coming.

What tyres are you running?
I just ordered Project Mu 800 for Gen 3 Brakes and Z2221 Semi for MTC16 in hope to get under 1:10.
I will be at Mallala on the 26th Sept.
I be using EBC Reds with new Rotors and Toyo R1R with E85. If I'm up it I hope can get closer to that 1:20 mark. But these tyres and bake may cost me time.
 

Just try to have your front fans on full time will on the Track.
 

I've been pretty busy so haven't really done anything on the car front yet, except booking for the roll cage which is going to "severely damage" my bank account :(
 
Not sure what coolant I currently have in there, but I'm planning on looking into the whole cooling system, and possibly getting a new radiator, some new hoses, coolant flush, driver controlled fan(s), etc..
 
My current tyres are Yokohama AD08R (235 and 215).

grosso
Just try to have your front fans on full time will on the Track.
 

The fans to jack all when going faster than 60 clicks. All they do is interfere with the natural airflow through the front of the car.

EssDub

grosso
Just try to have your front fans on full time will on the Track.
 

The fans to jack all when going faster than 60 clicks. All they do is interfere with the natural airflow through the front of the car.

It works well with my car.
I do have Mishimoto x-line radiator w/fans and shroud in my car.

Lucas
So I had a chat today to Simon from SimonBuilt and Lance from Walker Chassis regarding full roll cage. Hopefully I'll get around to preparing the car for it (removing the interior inc. sound deadening etc..) in Mid Oct.
 
And today I purchased this sweet 6 Point Harness. Another Velo product. Not that I can do anything with it until the whole safety system is in place (seat, harness, HANS, and rollcage)
 
Next is Hans+Helmet, and then the full cage should be the last piece of the safety puzzle :)

An other idea could try cutting a hole in front where the spare wheel is behind the radiator then then duct it out of the top of the bonnet like B24 Car.