BMW gets it! sort of
 

while people on this board prove every day that small inexpensive changes can have a big impact on FE, carmakers are slow to catch on.

still BMW these days has a number of interesting features in production that hopefully will soon be adopted by other car makers, but if nothing else, could sever as an argument next time someone redicules your cardboard grillblock etc.

theres some simplistic but cool animations that explain every feature

BMW EfficientDynamics : Air vent control

I LOVE the idea of an actuated grill block. I have thought about how to do it numerous times and have a descent system worked up. The only problem I see is icing up in winter time.

i'm working on my own simplified version of this... a single louver will be opened by a 12v motor when the fan kicks in... i've ran a static version of the grillblock at 30°C/ 86F exterior temp... and than the car started to get really hot so i had to take it off.
at 25C/77F engine temps are right where they should be with the block in place.

the only time when i see "normal" people use a grillblock is in winter , so i doubt you can make a car overheat than... but given the proximity to the radiator to the system i think it's got a great defroster behind it, should that be a problem.

what's the biggest hurdle is make something that works reliable enough to trust it to open when your fan kicks in... i'd wire up some led's to monitor the door but for not i haven't been able to build something that's reliable enough

Temperature Activated Switch Kit > Maplin
this circuit might help

as long as it ices up closed! :thumbup:

@modmonster

i've thought of something that looks very similar, but i think i'd just wire ip up to the fan... if somethings wrong witht he fan it'll show on the dash lights and i could hook up a led to the fan fuse terminal that'd save me some wireing.

yesterday i discovered why my temps stay so normal with the grillblock... teh tape holding it shut had come off and the airflow can just blow the doors open....

keeping the door in the right position will be another thing to tackle... a worm gear might work as it won't allow rotations to be transfered back from the door to the motor... but it's hard to find good gears...

common equipment on farm tractors built even before I was born, LOL (not for aero but temp control)

Radiator Shutters

well, as for the icing in the winter..

if it doesn't work.. FORCE IT!!!

Good for them! The T-100 is poised for this,however for now the ogival piston air valve is stationary.After my shop is further along,I can complete that project.Should help this winter,as along with the bellypan,I can close off the engine compartment when parked to conserve heat.