New Radiator with F1 tech core
So we've been playing with a new project at BWR. Our Ultimate street car has been upgraded with alot more power with full racegas tune etc. This car is seeing alot of track duty and combined with the front mount intercooler, we've had trouble keeping temps down. Additionally, I wanted to get some weight out of the radiator compared to the big double thick monster in the XP car.
So after talking to several experts in the field, we found a radiator core like none other. It is the Denso F1 core.
It is called the F1 core because F1 cars(as well as NASCAR, INDY etc) use it.
What makes it special? Essentially the tube spacing of the car is very small, only 0.25" center on center vs 0.4" So there are more tubes running across which gives more surface area for the water. Additionally, the fin spacing is very high at 21 Fins per Inch vs 14-18 for other solutions. This gives more surface area for the air to transfer heat.
Here's the last bit that will blow your mind. It is 27mm thick. Yep, not 42, not 45mm, 27mm. That's it.
How can that possibly work? Simple. Specific heat of water is 4.2 times higher than air. That means it takes 4.2 times more energy to heat a qty of water 1 degree than air.
When the cooler outside air hits the radiator, the air heats up 4.2 times the rate the water cools down. Thus the outside face of the radiator does alot of cooling but halfway through the radiator, the air is much hotter but the water only a little cooler. So the back half of the radiator doesn't do much since cooling is also a function of delta between the water and air temps. As the radiator experts told me, the first 1/3 of the radiator does 2/3s of the cooling.
Better to make the radiator thinner, use more tubes and fins to get the flow and surface area for the water and air to exchange heat. This is a more expensive manufacturing process.
We just tested this design on the car this weekend. The car did not get above 190F and recovers much faster. Previously we would see 225F+ Although contrary to conventional wisdom, this radiator will support over 400HP
The last advantage is obviously less weight. It is lighter by over a lb and saves even more in water weight.
The only downside is that it is spendy. We are able to save costs because 1 core is double height of the lotus radiator so we can use one core for 2 radiators. Even with this we are talking about a $725-$750 radiator.
Are there any hardcore autox or track folks that want the lightest and best? Post if you're in and and I'll look at putting a batch together.