An Eco endurance car, huh? At least you've got a closed deck. The cooler you keep that engine the better off you'll be on durability. Any knock ends things quickly. Whatever you think you need in terms of cooling, you probably need an extra 25%. By the time you get into the following morning on a long race, the rads are full of so much crap they lose a ton of efficiency.@fatbillybob How is that setup working for you. How long are your track sessions? I am building a endurance racer (6-24 hour races) with a A10 and was wondering if the flow through the cooling circuit is enough? I'm swapping the a 2.3 a10 setup into a smaller car. In a effort to limit the number of heat exchangers crammed into the limited space I have I was gong to try a water to tranny cooler from a dodge truck. I figure if it can keep a heavy duty track tranny cool during towing it should be able to keep up with a 2700 lbs racecar