OK, so.... I feel like there is a lot of myth and speculation surrounding these S197 cars with respect to cooling - most notably around these parts: grills, brands of radiators, oil coolers, and hoods.
First of all, the GT500s are terrible track cars. The supercharged engine is a massive heat soaked mess. It is a great drag race car. The 5.0 Boss302 and GT are the only track worthy models of the Mustang in the past 4 years, so I'm just ignoring the GT500.
Of these two models the GT's
don't seem to have overheating problems but the Boss302s sure do. They overheat with mild track use as delivered from the factory and it only gets worse they harder they are driven on track, especially at high altitude and in high ambient temps. Ford has sent out a considerable number of free parts and upgrades to Boss302 owners that had overheating issues - kudos to them for some good customer service. And after enough parts get changed out they
seem to overheat
less. But they rarely achieve the rock solid cooling of the GTs.
For the Boss302s I've see all sorts of tricks and doo-dads, special hoods and grills, but the 2011-14 GTs just have virtually no overheating problems with the same motor and power levels. Why is that? What is different on the Boss302?
Two things pop out to us, and they are things we have removed from Boss302s that see track use - with positive results:
1. The factory coolant/oil "cooler" is not a very good design that, we feel strongly, should be removed. It is an oil
heater. The GTs don't have this design and they don't overheat on track. So....
2. The transmission "scoop" cooler. The picture above is a Shelby piece, but the Boss302 unit is just as bad.
But wait, how could this shovel mounted under the car negatively affect the engine/oil cooling? Simply from the massive disruption of airflow under the car it creates. See, the "scoop" is trying to divert under car air flow up towards to the Getrag MT-82 train wreck of a transmission (that can and does overheat badly - we turned 3rd gear blue before it failed). Well what does that scoop really do? Its a huge addition to drag, and
we think it creates a high pressure area under the car that then backs up airflow trying to exit the engine bay... all of that air coming into the upper and lower front grills needs
somewhere to GO. In a stock Boss302 this airflow has to pass through the radiator then exit under the car.... and very possibly it gets
bogged down in the turbulence caused by the "trans scoop".
Now, we haven't done scientific pressure monitoring or wind tunnel testing on the trans scoop, of course. But we HAVE removed these silly trans scoops on some of our customers' Boss302s and some overheating complaints have been reduced. We've also replaced the Boss302 coolant-based oil cooler with the GT radiator hoses added an external fluid-to-air oil cooler with very positive results. We done both to a customer's heavily tracked boss302, which we also added external gauges to, and oil temps dropped markedly.
Venting the hood (aka: Tiger Racing hood) helps the Boss302s so much - and again this is speculation - because we think it allows the backed-up airflow from from the engine bay to finally exhaust out, which the pooper scooper is blocking.
The Boss302 guys flock to the Tiger Racing hoods
because it makes such a huge difference for them. And it looks "cool". If you already have this hood - great. It works. But maybe
first you guys with overheating Boss302s could go and unbolt that
ding-dong trans scoop under the car and do another track event - and then
watch the temps. This one simple "de-mod" alone could make as much or more of a difference as the TR hood, before you drop $2K on the hood + bodywork + fitting + painting. Removing the pooper scooper would obviously cost a lot less, but also crack a lot less, and fit better than these hoods do, in my opinion.
This Pikes Peak ~630 whp Subaru we're working on now has a hood vent similar to the GT500 style
Another upgrade is to remove the factory oil cooler and possibly add an external oil cooler. There are several kits out there around $1000, complete. Maybe try the much larger all-aluminum Mishimoto (or Ford Racing or another) radiator. At least the Mishimoto unit is cheap (right now MAP is $247). And if you want to vent the hood you could just add the GT500's ~$75 plastic hood vent, up at the front of the engine bay in a low pressure zone (not so far back as the Tiger Racing hood's vents, which are a higher pressure area - that won't extract as well). That's my opinion...
For reference, we had no oil cooler nor an aftermarket radiator in our Mustang
GT for the first 3 years of track use. With 430+ whp and ambient temps often above 100°F - and usually 2 people double-driving this car at each event - for 30+ events per year, we had no oil or coolant overheating problems, while setting track records. No problemo. We use 15W50 Mobil1 oil and change it religiously. That was the extent of the changes to the cooling or oiling for the first 3 years.
When we wanted to make a more functional front splitter we
completely blocked off the upper grill (oh n0es!!11!!one!!) and all of the incoming airflow for the radiator now comes from
just the lower opening, sealed to the a/c condenser (gasp!) and radiator.
We upgraded to a Mishimoto aluminum unit at the same time as we updated the front aero. Why? Because it was so cheap and we wanted to test it out. Of course we have reverse ducted the hood, which also works wonders. But the engine cooling is now
rock-freakin-solid. Still no oil cooler, either.
The stock GT radiator with plastic end caps is on the bottom. The ~$250 Mishimoto radiator is on top
Ford Racing and others make beautiful radiators, but most of those cost double what the Mishimoto S197 unit does (or more - some are $700+). Sure, one or two of them have an internal coolant-to-oil cooler stuffed inside one of the end tanks, but again - not a big fan of that type of "oil cooler". Nothing beats a dedicated, external air-to-oil cooler for effectiveness on track.
Anyway, that's my two cents. Take that series of observations as you will...
Cheers,