I have 2 bracket cars.On one ,I installed a blanket as soon as it was fast enough to need one,and the temps went way up.And this thing gets cooled between rounds.The second one got the CSR sheild once it was fast enough,without a noticable increase in temps.Both of them have front mounted coolers,and I have had the same convertor in both cars at one time or another.

So really the only difference I can see is the blanket for retaining heat,I can only imagine what it would do on the street.