The Type I DTM took me 8 months of trial and error to beat the best stock system in head temps. It was very easy to beat stock on ultimate cooling on just one side of the engine (right side) but the left side took alot of work. I finally incorporated airfoils, and another diverter and the cooling was cured.
The TI DTM is not sold with a thermostst and won't be. These systems are hand built and already suck up a tremendous amount of labor to assemble. Flaps and a Tstat could be added, however the cost would exceed what anyone could pay. I finished development of this system to be a benefit for performance engines that warm up much quicker than stock, and last winter I measured just how each system warmed up on the same engine, at the same temp in a stone cold 28 degree dyno cell (reversed the exhaust fan and pumped in cold air)
The difference was about 3-5 minutes different on oil temps and maybe
1-2 minutes different on head temps. basically the thermostat was used by VW for a great reason. When I tested the difference in the flaps and T stat for cooling I saw temps rise(maybe 5-8 degrees) and keep the same splits as without the flaps. If someone wants flaps they could arrange them on their own. I have a test version of them but there were so many ways that they could fail and CREATE an issue on the DTM that I have not incorporated them.
Once again, remember that I was testing temps on all 4 cylinders, in 3 different locations on each cylinder and head and inputting data every
2 minutes of engine run time. The same thing was done in the 66 test car but only with 4 head temp gauges.
The shroud is NOT compatible with Berg linkage on purpose.
The DTM diverts 17-20% more air through the cooler cavity than a stock doghouse, with about 10% more velocity. That coupled with the larger TIV oil cooler is a winning combination for oil temps.
The one thing I will add is that ALL ENGINES ARE VASTLY DIFFERENT! I quickly noted after testing 4 engines with the same shroud (aftermarket heads, different cylinders, different shimmage) that it was impossible to create a Type I system that is perfect for everyone!!! My shroud works better with aftermarket heads with less fins (it booosts pressure and then my airfoils and diverters do their job better). Some people will see huge gains on head temps and even temps all around the engine, while some people will see less of a gain. Everyone will benefit from the added air to the oil cooler, as well as the larger cooler overall.
I have put everything I possibly can into this system, and finally found the middle ground that will help enthusiast cool their engines better. The one thing to remember is that COOLING CAPABILITY MUST BE ATTAINED BEFORE ANY COOLING SYSTEM WILL BE EFFECTIVE! On the Type I hundreds of things effect this capability, some that we will never encounter. There will always be guys with misconfigured engines that are heat generators, and mistuned engines that will operate on the brink of meltdown. No cooling system will help those engines.